Topical Collection "Heterocycle Reactions"

Molbank 2023, 2023(2), M1614; https://doi.org/10.3390/M1614 - 30 Mar 2023

Viewed by 121

Abstract

Non-fullerene acceptors have recently attracted much attention as components of organic solar cells. 1H-indene-1,3(2H)-dione is a key compound for the synthesis of the end-capping component of non-fullerene acceptors. In this communication, an intermediate for the synthesis of this compound, [...] Read more.

Non-fullerene acceptors have recently attracted much attention as components of organic solar cells. 1H-indene-1,3(2H)-dione is a key compound for the synthesis of the end-capping component of non-fullerene acceptors. In this communication, an intermediate for the synthesis of this compound, tert-butyl (E)-3-oxo-2-(3-oxoisobenzofuran-1(3H)-ylidene)butanoate, was prepared by the reaction between phthalic anhydride and tert-butyl acetoacetate. Further treatment with sodium methoxide in methanol led to the formation of 1H-indene-1,3(2H)-dione in a high yield. The structure of the newly synthesized compound was established by means of elemental analysis, high-resolution mass spectrometry, ¹H, ¹³C NMR, IR spectroscopy, mass spectrometry and X-ray analysis. Full article

New 2-(2,4-Dihydroxyphenyl)benzimidazolines

Figure 1

Open AccessShort Note

by

Yordan Stremski

,

Maria Bachvarova

,

Desislava Kirkova

and

Stela Statkova-Abeghe

Molbank 2023, 2023(1), M1602; https://doi.org/10.3390/M1602 - 10 Mar 2023

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Abstract

New 2-(2,4-dihydroxyphenyl)benzimidazolines are synthesized in an easily accessible approach. The method is based on the reaction of resorcinol with in situ-formed electrophilic N-ethoxycarbonylbenzimidazolium reagents. The structure of the two newly formed products was spectrally characterized by 1D and 2D NMR, IR, and [...] Read more.

New 2-(2,4-dihydroxyphenyl)benzimidazolines are synthesized in an easily accessible approach. The method is based on the reaction of resorcinol with in situ-formed electrophilic N-ethoxycarbonylbenzimidazolium reagents. The structure of the two newly formed products was spectrally characterized by 1D and 2D NMR, IR, and MS spectral analyses. Full article

4,4′-Difluoro-[3,3′-bi(1,2,5-oxadiazole)] 2,2′-Dioxide

Graphical abstract

Open AccessShort Note

by

Natalia V. Obruchnikova

and

Molbank 2023, 2023(1), M1596; https://doi.org/10.3390/M1596 - 23 Feb 2023

Viewed by 435

Abstract

1,2,5-Oxadiazole oxides (furoxans) are well known nitric oxide donors; among them, 4-fluorofuroxans have recently been found to be important photoinduced nitric oxide donors. In this research, it was shown that the reaction of 4,4′-dinitro-[3,3′-bi(1,2,5-oxadiazole)] 2,2′-dioxide with fluoro-containing reagents (tetrabutylammonium fluoride or cesium fluoride) [...] Read more.

1,2,5-Oxadiazole oxides (furoxans) are well known nitric oxide donors; among them, 4-fluorofuroxans have recently been found to be important photoinduced nitric oxide donors. In this research, it was shown that the reaction of 4,4′-dinitro-[3,3′-bi(1,2,5-oxadiazole)] 2,2′-dioxide with fluoro-containing reagents (tetrabutylammonium fluoride or cesium fluoride) selectively gave the bis-substitution product 4,4′-difluoro-[3,3′-bi(1,2,5-oxadiazole)] 2,2′-dioxide. The structure of the synthesized compound was established by elemental analysis, ¹³C, ¹⁹F-NMR and IR spectroscopy, and mass-spectrometry. Full article

(E)-1-(5-Methyl-1-(4-nitrophenyl)-1H-1,2,3-triazol-4-yl)ethan-1-one Oxime

Scheme 1

Open AccessShort Note

by

Bakr F. Abdel-Wahab

,

Abdelbasset A. Farahat

,

Benson M. Kariuki

and

Gamal A. El-Hiti

Molbank 2023, 2023(1), M1593; https://doi.org/10.3390/M1593 - 21 Feb 2023

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Abstract

The reaction of 1-(5-methyl-1-(4-nitrophenyl)-1H-1,2,3-triazol-4-yl)ethan-1-one (1) with excess hydroxylamine hydrochloride (2 mole equivalents) in dry ethanol afforded (E)-1-(5-methyl-1-(4-nitrophenyl)-1H-1,2,3-triazol-4-yl)ethan-1-one oxime (2) in 86% yield. The structure of the new heterocycle 2 was confirmed using nuclear magnetic resonance spectroscopy, single crystal X-ray and elemental analysis. Full article

Triethylammonium 2-(3-Hydroxy-2-oxoindolin-3-yl)-5,5-dimethyl-3-oxocyclohex-1-en-1-olate

Graphical abstract

Open AccessShort Note

by

Yuliya E. Ryzhkova

,

Fedor V. Ryzhkov

and

Michail N. Elinson

Molbank 2023, 2023(1), M1589; https://doi.org/10.3390/M1589 - 15 Feb 2023

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Abstract

In recent years, the application of privileged structures has become a powerful approach in the discovery of new biologically active molecules. Ion pairing is a strategy used to enhance the permeation of ionized topical drugs. A convenient and efficient method for the synthesis [...] Read more.

In recent years, the application of privileged structures has become a powerful approach in the discovery of new biologically active molecules. Ion pairing is a strategy used to enhance the permeation of ionized topical drugs. A convenient and efficient method for the synthesis of triethylammonium 2-(3-hydroxy-2-oxoindolin-3-yl)-5,5-dimethyl-3-oxocyclohex-1-en-1-olate has been developed. The presented protocol includes an aldol reaction and the formation of an ammonium salt. Triethylamine is both a reactant and a catalyst in the process. The structure of the synthesized title compound has been established by ¹H, ¹³C-NMR and IR spectroscopy, mass spectrometry, and elemental analysis. Full article

4-Benzoyl-2-(4-bromophenyl)-1-(4-methoxyphenyl)-1,2-dihydropyrimidino[4,3-c][1,4]benzoxazine-3,5-dione

Graphical abstract

Open AccessShort Note

by

Ekaterina E. Khramtsova

,

Maksim V. Dmitriev

and

Andrey N. Maslivets

Molbank 2023, 2023(1), M1583; https://doi.org/10.3390/M1583 - 08 Feb 2023

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Abstract

The reaction of 3-benzoylpyrrolo[2,1-c][1,4]benzoxazin-1,2,4-trione with N-(4-bromophenyl)-1-(4-methoxyphenyl)methanimine under thermolytical conditions afforded 4-benzoyl-2-(4-bromophenyl)-1-(4-methoxyphenyl)-1,2-dihydropyrimidino[4,3-c][1,4]benzoxazine-3,5-dione in a good yield. The reaction proceeded via in situ generation of a reactive intermediate, acyl(imidoyl)ketene. The compound was fully characterized. Full article

(Z)-3-(Dicyanomethylene)-4-((5-fluoro-3,3-dimethyl-1-(3-phenylpropyl)-3H-indol-1-ium-2-yl) methylene)-2-(((E)-5-fluoro-3,3-dimethyl-1-(3-phenylpropyl)indolin-2-ylidene)methyl) cyclobut-1-en-1-olate

Figure 1

Open AccessShort Note

by

Stefanie Casa

,

Guliz Ersoy Ozmen

and

Maged Henary

Molbank 2023, 2023(1), M1576; https://doi.org/10.3390/M1576 - 03 Feb 2023

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Abstract

Recent literature on this topic highlights the significance of adding malononitrile moiety and halogen substituents to the squaraine scaffold to create redshifted fluorophores into the near-infrared optical region. Herein, a redshifted hydrophobic squaraine dye is synthesized via a three-step pathway. The reported dye [...] Read more.

Recent literature on this topic highlights the significance of adding malononitrile moiety and halogen substituents to the squaraine scaffold to create redshifted fluorophores into the near-infrared optical region. Herein, a redshifted hydrophobic squaraine dye is synthesized via a three-step pathway. The reported dye is characterized by spectroscopic techniques, such as ¹H NMR, ¹⁹F NMR, ¹³C NMR, and high-resolution mass spectroscopy. Optical properties are also reported using absorbance and fluorescence studies. The hydrophobicity of the dye was studied with absorbance and fluorescence spectroscopy in water–methanol mixtures and showed J-aggregates as the water concentration increased. Density functional theory calculations were conducted to assess its electron delocalization as well as observe the three-dimensional geometry of the dye as a result of the dicyanomethylene modification and the two bulky phenyl groups. Full article

6-Chloro-3-nitro-2-[(phenylsulfonyl)methyl]imidazo[1,2-b]pyridazine

Graphical abstract

Open AccessShort Note

by

Romain Paoli-Lombardo

,

Nicolas Primas

,

Sébastien Hutter

,

Sandra Bourgeade-Delmas

,

Clotilde Boudot

,

Caroline Castera-Ducros

,

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and

Molbank 2023, 2023(1), M1573; https://doi.org/10.3390/M1573 - 01 Feb 2023

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Abstract

As part of our ongoing scaffold-hopping work on an antikinetoplastid 3-nitroimidazo[1,2-a]pyridine scaffold, we explored 3-nitroimidazo[1,2-b]pyridazine as a potential new antikinetoplastid series. Using conditions previously described by our lab, we obtained 6-chloro-3-nitro-2-[(phenylsulfonyl)methyl]imidazo[1,2-b]pyridazine with 54% yield. In vitro activity [...] Read more.

As part of our ongoing scaffold-hopping work on an antikinetoplastid 3-nitroimidazo[1,2-a]pyridine scaffold, we explored 3-nitroimidazo[1,2-b]pyridazine as a potential new antikinetoplastid series. Using conditions previously described by our lab, we obtained 6-chloro-3-nitro-2-[(phenylsulfonyl)methyl]imidazo[1,2-b]pyridazine with 54% yield. In vitro activity of this compound was evaluated against both the promastigote form of Leishmania donovani, the axenic amastigote form of Leishmania infantum and the trypomastigote blood stream form of Trypanosomabrucei brucei, and its influence on cell viability was assessed on the HepG2 cell line. However, despite good activity against the trypomastigote blood stream form of T. b. brucei (EC₅₀ = 0.38 µM), it showed poor solubility in both HepG2 (CC₅₀ > 7.8 µM) and L. infantum axenic amastigotes (EC₅₀ > 1.6 µM) culture media, associated with a loss of activity against the promastigote form of L. infantum (EC₅₀ > 15.6 µM). Full article

(3-(1H-Indol-3-yl)-2-(7,8,12,13-tetraoxa-10-azaspiro[5.7]tridecan-10-yl)propanoic acid) with Cytotoxic Activity

Figure 1

Open AccessCommunication

by

Nataliya N. Makhmudiyarova

,

Irina R. Ishmukhametova

,

Lilya U. Dzhemileva

and

Usein M. Dzhemilev

Molbank 2023, 2023(1), M1572; https://doi.org/10.3390/M1572 - 01 Feb 2023

Viewed by 419

Abstract

An efficient method for the synthesis of 3-(1H-indol-3-yl)-2-(7,8,12,13-tetraoxa-10-azaspiro[5.7]tridecan-10-yl)propanoic acid) via condensation of 7,8,10,12,13-pentaoxaspiro[5.7]tridecane with tryptophan under the action of a catalyst based on Sm(NO₃)₃·6H₂O has been developed. A high cytotoxic activity of eight-membered azadiperoxide against [...] Read more.

An efficient method for the synthesis of 3-(1H-indol-3-yl)-2-(7,8,12,13-tetraoxa-10-azaspiro[5.7]tridecan-10-yl)propanoic acid) via condensation of 7,8,10,12,13-pentaoxaspiro[5.7]tridecane with tryptophan under the action of a catalyst based on Sm(NO₃)₃·6H₂O has been developed. A high cytotoxic activity of eight-membered azadiperoxide against tumor cells Jurkat, K562, U937, and HL60 was established. Additionally, this compound is an inducer of apoptosis and affects the cell cycle. Full article

2-{9-(10-Bromoanthracenyl)}-1,3-dihydro-1H-[d]-1,3,2-benzodiazaborole

Figure 1

Open AccessShort Note

by

Siphamandla Sithebe

Molbank 2023, 2023(1), M1569; https://doi.org/10.3390/M1569 - 27 Jan 2023

Viewed by 511

Abstract

In this paper, a synthesis and characterization of a novel three coordinate 2-{9-(10-Bromoanthracenyl)}-1,3-dihydro-1H-[d]-1,3,2-benzodiazaborole from a cyclo-condensation reaction of o-phenylenediamine and 10-bromoanthracene-9-boronic acid is described. The desired product was obtained in 0.343 g (92% yields) with its structure characterized [...] Read more.

In this paper, a synthesis and characterization of a novel three coordinate 2-{9-(10-Bromoanthracenyl)}-1,3-dihydro-1H-[d]-1,3,2-benzodiazaborole from a cyclo-condensation reaction of o-phenylenediamine and 10-bromoanthracene-9-boronic acid is described. The desired product was obtained in 0.343 g (92% yields) with its structure characterized by ¹H, ¹¹B, ¹³C NMR, HRMS and FT-IR. Full article

Synthesis of Pentacycloundecane (PCUD) Based Spiro-Pyrano-Cage Framework via Ring-Closing Metathesis

Scheme 1

Open AccessCommunication

by

Sambasivarao Kotha

,

Mohammad Salman

and

Subba Rao Cheekatla

Molbank 2023, 2023(1), M1567; https://doi.org/10.3390/M1567 - 23 Jan 2023

Viewed by 660

Abstract

Here, we demonstrate a short synthetic route to pyrano cage systems containing pentacycloundecane units by employing ring-closing metathesis (RCM) as a key step. These cage systems were constructed starting with readily available starting materials by adopting atomic economic processes such as cycloadditions (Diels-Alder [...] Read more.

Here, we demonstrate a short synthetic route to pyrano cage systems containing pentacycloundecane units by employing ring-closing metathesis (RCM) as a key step. These cage systems were constructed starting with readily available starting materials by adopting atomic economic processes such as cycloadditions (Diels-Alder reaction and [2+2] cycloaddition), Grignard addition, and olefin metathesis. The key building block, such as hexacyclic cage dione, was prepared from 1,4-naphthoquinone derivative and freshly cracked 1,3-cyclopentadiene. Some of these heterocyclic motifs are useful in biological chemistry and valuable as key synthons for high-energy-density materials. Full article

Synthesis of Bis(1,2,3-triazolyl)alkanes in Superbasic and Solvent-Free Conditions

Figure 1

Open AccessCommunication

by

Roman D. Marchenko

and

Andrei S. Potapov

Molbank 2023, 2023(1), M1551; https://doi.org/10.3390/M1551 - 13 Jan 2023

Viewed by 637

Abstract

Nucleophilic substitution reactions between 1,2,3-triazole and dibromomethane or 1,2-dirbomoethane in a superbasic medium potassium hydroxide–dimethyl sulfoxide gave mixtures of the isomeric bis(1,2,3-triazolyl)alkanes, in which (1,2,3-triazol-1-yl)(1,2,3-triazol-2-yl)alkanes and bis(1,2,3-triazol-2-yl)alkanes were the dominating products, while bis(triazol-1-yl)alkanes were detected only in trace amounts. The same products could [...] Read more.

Nucleophilic substitution reactions between 1,2,3-triazole and dibromomethane or 1,2-dirbomoethane in a superbasic medium potassium hydroxide–dimethyl sulfoxide gave mixtures of the isomeric bis(1,2,3-triazolyl)alkanes, in which (1,2,3-triazol-1-yl)(1,2,3-triazol-2-yl)alkanes and bis(1,2,3-triazol-2-yl)alkanes were the dominating products, while bis(triazol-1-yl)alkanes were detected only in trace amounts. The same products could also be obtained under solvent-free conditions in a neat reaction mixture. The proposed methods are economically feasible, do not require using toxic solvents or catalysts, and make the (1,2,3-triazol-2-yl)-derivatives, inaccessible by alkyne-azide cycloaddition (click) reactions, readily available. Full article

2,4-Diamino-5-(5-hydroxy-1-phenyl-3-(trifluoromethyl)-1H-pyrazol-4-yl)-5H-chromeno[2,3-b]pyridine-3-carbonitrile

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by

,

,

and

Molbank 2023, 2023(1), M1541; https://doi.org/10.3390/M1541 - 09 Jan 2023

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Abstract

5H-Chromeno[2,3-b]pyridines are important compounds with industrial, biological, and medicinal properties. In this short note, the multicomponent reaction of salicylaldehyde, malononitrile dimer, and 2-phenyl-5-(trifluoromethyl)-2,4-dihydro-3H-pyrazol-3-one in dimethyl sulfoxide at ambient temperature was investigated to give 2,4-diamino-5-(5-hydroxy-1-phenyl-3-(trifluoromethyl)-1H-pyrazol-4-yl)-5H [...] Read more.

5H-Chromeno[2,3-b]pyridines are important compounds with industrial, biological, and medicinal properties. In this short note, the multicomponent reaction of salicylaldehyde, malononitrile dimer, and 2-phenyl-5-(trifluoromethyl)-2,4-dihydro-3H-pyrazol-3-one in dimethyl sulfoxide at ambient temperature was investigated to give 2,4-diamino-5-(5-hydroxy-1-phenyl-3-(trifluoromethyl)-1H-pyrazol-4-yl)-5H-chromeno[2,3-b]pyridine-3-carbonitrile with good yield. The structure of the previously unknown chromeno[2,3-b]pyridine derivative was confirmed by elemental analysis, mass, nuclear magnetic resonance, and infrared spectroscopy data. The ADME (absorption, distribution, metabolism, and excretion) properties were also assessed. Full article

2-[2-(Diphenylphosphoryl)phenyl]-1H-perimidine

Graphical abstract

2022

Jump to: 2023, 2021, 2020, 2019

Open AccessShort Note

by

Mangaliso N. Goge

,

Siphamandla Sithebe

and

Tshephiso R. Papo

Molbank 2023, 2023(1), M1537; https://doi.org/10.3390/M1537 - 29 Dec 2022

Viewed by 735

Abstract

In this paper, we report the crystal structure of 2-[2-(diphenylphosphoryl)phenyl]-1H-perimidine (L1) obtained from the ring closure reaction of 1,8-diaminonaphthalene and 2-(diphenylphosphino)benzaldehyde, followed by the dehydrogenation reaction with sodium metabisulfite (Na₂S₂O₅). L1 was characterised using ¹H, ¹³ [...] Read more.

In this paper, we report the crystal structure of 2-[2-(diphenylphosphoryl)phenyl]-1H-perimidine (L1) obtained from the ring closure reaction of 1,8-diaminonaphthalene and 2-(diphenylphosphino)benzaldehyde, followed by the dehydrogenation reaction with sodium metabisulfite (Na₂S₂O₅). L1 was characterised using ¹H, ¹³C & ³¹P NMR, FT-IR and X-ray single structure analyses. Full article

1-(4-{[3,5-bis({[3,5-Dimethyl-4-(4-methyl-3,5-dioxo-1,2,4-triazolidin-1-yl)-phenoxy]methyl})phenyl]methoxy}-2,6-dimethyl-phenyl)-4-methyl-1,2,4-triazolidine-3,5-dione

Figure 1

Open AccessCommunication

by

Gary W. Breton

and

James Alexander Bowron, Jr.

Molbank 2023, 2023(1), M1535; https://doi.org/10.3390/M1535 - 27 Dec 2022

Viewed by 552

Abstract

Appropriately substituted N-centered urazolyl radicals are capable of generating interesting cage-like structures upon forming N-N bonds. The radicals are generated by the oxidation of the corresponding NH urazole precursors. We synthesized a triurazole precursor that we hoped would dimerize through the formation of [...] Read more.

Appropriately substituted N-centered urazolyl radicals are capable of generating interesting cage-like structures upon forming N-N bonds. The radicals are generated by the oxidation of the corresponding NH urazole precursors. We synthesized a triurazole precursor that we hoped would dimerize through the formation of three N-N bonds to afford a large molecular cage. Unfortunately, the attempts at the oxidation of the urazoles to form urazolyl radicals instead only lead to random oligomerization, forming plastic-like materials rather than the desired cages. Full article

1-[2-(1H-Pyrrole-2-carbonyl)phenyl]-3-(4-methoxyphenyl)urea

Figure 1

Open AccessShort Note

by

Antonia G. Sarantou

and

George Varvounis

Molbank 2023, 2023(1), M1531; https://doi.org/10.3390/M1531 - 22 Dec 2022

Viewed by 833

Abstract

For the synthesis of 1-(2-(1H-pyrrole-2-carbonyl)phenyl)-3-(4-methoxyphenyl)urea, the final product, two different methods were used, in one or two steps, from (2-aminophenyl)(1H-pyrrol-2-yl)methanone. The one-step synthesis entailed a carbonylation reaction with 1/3 equivalent of triphosgene in the presence of two equivalents of [...] Read more.

For the synthesis of 1-(2-(1H-pyrrole-2-carbonyl)phenyl)-3-(4-methoxyphenyl)urea, the final product, two different methods were used, in one or two steps, from (2-aminophenyl)(1H-pyrrol-2-yl)methanone. The one-step synthesis entailed a carbonylation reaction with 1/3 equivalent of triphosgene in the presence of two equivalents of trimethylamine, followed by the addition of 4-methoxyaniline to the in situ generated aryl isocyanate. The two-step synthesis required first the preparation of phenyl(2-(1H-pyrrole-2-carbonyl)phenyl)carbamate and then a substitution reaction by 4-methoxyaniline. The first method produced the final product in 72% yield, which was the best yield. The structure of the final product was confirmed by FTIR, UV-VIS, ¹H and ¹³C NMR spectroscopy and high resolution mass spectrometry. Full article

2-Benzyl-3-morpholino-7-(thiophen-2-yl)-6-(thiophen-2-ylmethyl)-6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-5-one

Figure 1

Open AccessShort Note

by

Ivette Morales-Salazar

,

Mónica A. Rincón-Guevara

,

Eduardo González-Zamora

and

Alejandro Islas-Jácome

Molbank 2022, 2022(4), M1503; https://doi.org/10.3390/M1503 - 23 Nov 2022

Viewed by 552

Abstract

The new polyheterocyclic compound 2-benzyl-3-morpholino-7-(thiophen-2-yl)-6-(thiophen-2-ylmethyl)-6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-5-one (1) was synthesized via a one-pot process involving an Ugi-Zhu three-component reaction coupled to a cascade aza-Diels-Alder cycloaddition/N-acylation/decarboxylation/dehydration process, using toluene as the solvent, ytterbium (III) triflate as the [...] Read more.

The new polyheterocyclic compound 2-benzyl-3-morpholino-7-(thiophen-2-yl)-6-(thiophen-2-ylmethyl)-6,7-dihydro-5H-pyrrolo[3,4-b]pyridin-5-one (1) was synthesized via a one-pot process involving an Ugi-Zhu three-component reaction coupled to a cascade aza-Diels-Alder cycloaddition/N-acylation/decarboxylation/dehydration process, using toluene as the solvent, ytterbium (III) triflate as the Lewis acid catalyst, and microwave-dielectric heating to increase the overall yield by up to 73%, while decreasing the reaction time to less than one hour. Product 1 was fully characterized by its physicochemical properties and using spectroscopic techniques (IR, HRMS and NMR). Full article

4-Methyl-7-((2-((5-methyl-1,3,4-thiadiazol-2-yl)thio)ethyl)thio)-coumarin

Graphical abstract

Open AccessShort Note

by

Vanya Kurteva

,

Rusi Rusew

and

Boris Shivachev

Molbank 2022, 2022(4), M1491; https://doi.org/10.3390/M1491 - 12 Nov 2022

Viewed by 908

Abstract

The novel compound 4-methyl-7-((2-((5-methyl-1,3,4-thiadiazol-2-yl)thio)ethyl)thio)-coumarin is obtained in good yield via a two-step protocol; that is, initial synthesis of the reagent 2-((2-chloroethyl)thio)-5-methyl-1,3,4-thiadiazole followed by alkylation of 7-mercapto-4-methylcoumarin. The product’s structure is assigned by 1D and 2D NMR experiments and is confirmed by single-crystal XRD. [...] Read more.

The novel compound 4-methyl-7-((2-((5-methyl-1,3,4-thiadiazol-2-yl)thio)ethyl)thio)-coumarin is obtained in good yield via a two-step protocol; that is, initial synthesis of the reagent 2-((2-chloroethyl)thio)-5-methyl-1,3,4-thiadiazole followed by alkylation of 7-mercapto-4-methylcoumarin. The product’s structure is assigned by 1D and 2D NMR experiments and is confirmed by single-crystal XRD. Full article

5-Chloro-6-oxo-6H-xantheno[4,3-d]thiazole-2-carbonitrile

Figure 1

Open AccessShort Note

by

Konstantinos Paraskevas

,

Christos Iliopoulos-Tsoutsouvas

,

Eleftheria A. Georgiou

and

Ioannis K. Kostakis

Molbank 2022, 2022(4), M1489; https://doi.org/10.3390/M1489 - 10 Nov 2022

Viewed by 780

Abstract

Xanthones and benzothiazoles are important classes of heterocyclic compounds with versatile biological activities. Herein, we describe a straightforward and scalable synthesis of 5-chloro-6-oxo-6H-xantheno[4,3-d]thiazole-2-carbonitrile, a thiazole-fused xanthone, via a six-step approach, using Appel’s salt for the synthesis of the thiazole [...] Read more.

Xanthones and benzothiazoles are important classes of heterocyclic compounds with versatile biological activities. Herein, we describe a straightforward and scalable synthesis of 5-chloro-6-oxo-6H-xantheno[4,3-d]thiazole-2-carbonitrile, a thiazole-fused xanthone, via a six-step approach, using Appel’s salt for the synthesis of the thiazole ring. The thiazole-fused xanthone was fully characterized employing ¹H and ¹³C NMR spectra, using direct and long-range heteronuclear correlation experiments (HMBC and HMQC). Full article

Synthesis and Characterization of 3-Methyl-1-(4-(trifluoromethyl)phenyl)indeno [1,2-c]pyrazol-4(1H)-one

Graphical abstract

Open AccessCommunication

by

Linh Lam

,

Sang H. Park

and

Joseph Sloop

Molbank 2022, 2022(4), M1483; https://doi.org/10.3390/M1483 - 07 Nov 2022

Viewed by 974

Abstract

Pyrazoles have potential applications in the agrochemical and medicinal chemistry industries as pesticides, anti-inflammatory medications, and antitumor drugs. Fluorinated fused-ring pyrazoles may also possess medicinally useful properties. Herein, we report the acid-catalyzed synthesis of a new tricyclic, trifluoromethylated indenopyrazole, 3-methyl-1-(4-(trifluoromethyl)phenyl)indeno[1,2-c]pyrazol-4(1H)-one, from [...] Read more.

Pyrazoles have potential applications in the agrochemical and medicinal chemistry industries as pesticides, anti-inflammatory medications, and antitumor drugs. Fluorinated fused-ring pyrazoles may also possess medicinally useful properties. Herein, we report the acid-catalyzed synthesis of a new tricyclic, trifluoromethylated indenopyrazole, 3-methyl-1-(4-(trifluoromethyl)phenyl)indeno[1,2-c]pyrazol-4(1H)-one, from 2-acetyl-1,3-indanedione and 4-trifluoromethylphenylhydrazine. This isomeric pyrazole was obtained in yields ranging from 4–24%. NMR spectroscopic characterization and elemental analysis support the structural assignment, identity, and purity of the product. Full article

Dimethyl 3,7-diamino-4,8-bis((2-methoxy-2-oxoethyl)thio)benzo[1,2-b:4,5-b’]dithiophene-2,6-dicarboxylate

Figure 1

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Molbank 2022, 2022(4), M1474; https://doi.org/10.3390/M1474 - 27 Oct 2022

Viewed by 605

Abstract

The convenient and multigram synthesis of a linear benzo[b]dithiophene (BDT) structure is proposed (dimethyl 3,7-diamino-4,8-bis((2-methoxy-2-oxoethyl)thio)benzo[1,2-b:4,5-b’]dithiophene-2,6-dicarboxylate). The starting materials are commercially available 2,3,5,6-tetrachloroterephthalonitrile and methyl 2-mercaptoacetate, which undergo aromatic substitution, followed by a cyclization reaction in basic conditions [...] Read more.

The convenient and multigram synthesis of a linear benzo[b]dithiophene (BDT) structure is proposed (dimethyl 3,7-diamino-4,8-bis((2-methoxy-2-oxoethyl)thio)benzo[1,2-b:4,5-b’]dithiophene-2,6-dicarboxylate). The starting materials are commercially available 2,3,5,6-tetrachloroterephthalonitrile and methyl 2-mercaptoacetate, which undergo aromatic substitution, followed by a cyclization reaction in basic conditions to form suitable BDT for potential optoelectronic applications. Full article

1-Phenyl-3-tosyl-1H-pyrrole

Figure 1

Open AccessShort Note

by

Zoumpoulia Kechagioglou

and

Vassilis J. Demopoulos

Molbank 2022, 2022(4), M1471; https://doi.org/10.3390/M1471 - 26 Oct 2022

Viewed by 632

Abstract

1-Phenyl-3-tosyl-1H-pyrrole was prepared, in moderate yield, by the electrophilic aromatic substitution of 1-phenyl-1H-pyrrole with tosyl chloride in the presence of excess zinc oxide under solvent-free conditions. A minor product was its isomer, 1-phenyl-2-tosyl-1H-pyrrole. Full article

3-Methyl 5-{3-[(4-Methylbenzenesulfonyl)oxy]propyl} 4-(2,3-Dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate

Scheme 1

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Molbank 2022, 2022(4), M1460; https://doi.org/10.3390/M1460 - 09 Oct 2022

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Abstract

The 1,4-dihydropyridine is a ubiquitous scaffold employed not only in medicinal chemistry but also in organic synthesis, given its ability to act as a hydrogen transfer reagent, thus emulating NAD(P)H reducing agents. In this work, we describe the synthesis of 3-methyl 5-{3-[(4-methylbenzenesulfonyl)oxy]propyl} 4-(2,3-dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate [...] Read more.

The 1,4-dihydropyridine is a ubiquitous scaffold employed not only in medicinal chemistry but also in organic synthesis, given its ability to act as a hydrogen transfer reagent, thus emulating NAD(P)H reducing agents. In this work, we describe the synthesis of 3-methyl 5-{3-[(4-methylbenzenesulfonyl)oxy]propyl} 4-(2,3-dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate as scaffold, which enables downstream derivatization towards new 1,4-dihydropyridine molecules. Inspired by the literature, a new two-step synthesis was planned that involved: (i) synthesis of a silylated 1,4-dihydropyridine derivative and (ii) deprotection and tosylation in one step using tosyl fluoride. Full article

Ferrocenyl-bis-(1-(4-benzyl-5-morpholinooxazol-2-yl)-N-(4-(trifluoromethyl)benzyl)methanamine)

Figure 1

Open AccessShort Note

by

Roberto E. Blanco-Carapia

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Enrique A. Aguilar-Rangel

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Alejandro Islas-Jácome

and

Eduardo González-Zamora

Molbank 2022, 2022(3), M1444; https://doi.org/10.3390/M1444 - 13 Sep 2022

Viewed by 864

Abstract

The new bis-heterocyclic compound ferrocenyl-bis-(1-(4-benzyl-5-morpholinooxazol-2-yl)-N-(4-(trifluoromethyl)benzyl)methanamine) (1) was synthesized in 73% overall yield in 1.5 hours via a pseudo-repetitive Ugi-Zhu five-component reaction, starting from 1,1′-ferrocenedicarboxaldehyde, 4-(trifluoromethyl)benzylamine, and 2-isocyano-1-morpholino-3-phenylpropan-1-one, in 1:2.1:2.2 proportions, respectively, using scandium(III) triflate as a [...] Read more.

The new bis-heterocyclic compound ferrocenyl-bis-(1-(4-benzyl-5-morpholinooxazol-2-yl)-N-(4-(trifluoromethyl)benzyl)methanamine) (1) was synthesized in 73% overall yield in 1.5 hours via a pseudo-repetitive Ugi-Zhu five-component reaction, starting from 1,1′-ferrocenedicarboxaldehyde, 4-(trifluoromethyl)benzylamine, and 2-isocyano-1-morpholino-3-phenylpropan-1-one, in 1:2.1:2.2 proportions, respectively, using scandium(III) triflate as a Lewis-acid catalyst, microwaves as a heat source, and toluene as a solvent. The synthesized compound was characterized by 1D (¹H, ¹³C, and ¹⁹F) and 2D (COSY, HSQC, and HMBC) NMR, HRMS, and FT-IR. Full article

1,1′-{[3,5-Bis((dodecyloxycarbonyl)-4-phenyl-1,4-dihydropyridine-2,6-diyl]bis(methylene)}bis[4-(anthracen-9-yl)pyridin-1-ium] Dibromide

Figure 1

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Molbank 2022, 2022(3), M1438; https://doi.org/10.3390/M1438 - 02 Sep 2022

Viewed by 892

Abstract

A synthesis of a cationic moiety and fluorescent moieties containing amphiphilic 1,4-dihydropyridine (1,4-DHP) derivatives was performed starting with the Hantzsch-type cyclization of dodecyl acetoacetate, phenylaldehyde and ammonium acetate. Bromination of the 2,6-dimethyl groups of a parent 1,4-DHP compound, followed by nucleophilic substitution of [...] Read more.

A synthesis of a cationic moiety and fluorescent moieties containing amphiphilic 1,4-dihydropyridine (1,4-DHP) derivatives was performed starting with the Hantzsch-type cyclization of dodecyl acetoacetate, phenylaldehyde and ammonium acetate. Bromination of the 2,6-dimethyl groups of a parent 1,4-DHP compound, followed by nucleophilic substitution of bromine with 4-(anthracen-9-yl)pyridine, produced the desired 1,1′-{[3,5-bis((dodecyloxycarbonyl)-4-phenyl-1,4-dihydropyridine-2,6-diyl]bis(methylene)}bis[4-(anthracen-9-yl)pyridin-1-ium] dibromide. The obtained target compound was fully characterized by the IR, ¹H NMR, ¹³C NMR and HRMS data. Studies of the self-assembling properties and characterization of the nanoparticles obtained by the ethanol injection method were performed using dynamic light scattering (DLS) measurements. DLS measurement data showed that 1,1′-{[3,5-bis((dodecyloxycarbonyl)-4-phenyl-1,4-dihydropyridine-2,6-diyl]bis(methylene)}bis[4-(anthracen-9-yl)pyridin-1-ium] dibromide produced liposomes that had average diameters of 200 nm when the samples were freshly prepared, and 140 nm after 7 days or 1 month storage. The PDI values of the samples were approximately 0.50 and their zeta-potential values were approximately 41 mV when the samples were freshly prepared, and 33 mV after storage. The obtained nanoparticles were stored at room temperature for one month and remained stable during that period. The mean molecular area of the cationic 1,4-DHP-anthracene hybrid 4 was 118 Å², while the mean molecular area of the cationic 1,4-DHP 5 without anthracene substituents was only 83 Å². The photoluminescence quantum yield (PLQY) value for the EtOH solution of the 1,4-DHP derivative 4 was 10.8%, but for the 1,4-DHP derivative 5 it was only 1.8%. These types of compounds could be used as synthetic lipids in the further development of prospective theranostic delivery systems. Full article

3-(1-Cyclohexyl-2-(cyclohexylamino)-4-(4-ethoxyphenyl)-6-oxo-1,6-dihydropyrimidin-5-yl)-1-methylquinoxalin-2(1H)-one

Figure 1

Open AccessShort Note

by

Ekaterina E. Khramtsova

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Svetlana O. Kasatkina

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Maksim V. Dmitriev

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Andrey N. Maslivets

Molbank 2022, 2022(3), M1421; https://doi.org/10.3390/M1421 - 05 Aug 2022

Viewed by 1001

Abstract

The reaction of 3-cyclohexyl-2-(cyclohexylimino)-6-(4-ethoxyphenyl)-5-(4-methyl-3-oxo-3,4-dihydroquinoxalin-2-yl)-2,3-dihydro-4H-1,3-oxazin-4-one with ammonium acetate afforded 3-(1-cyclohexyl-2-(cyclohexylamino)-4-(4-ethoxyphenyl)-6-oxo-1,6-dihydropyrimidin-5-yl)-1-methylquinoxalin-2(1H)-one in a good yield. The compound was fully characterized. Full article

12H-Dibenzo[d,g][1,2,3]triselenocin-12-ol

Figure 1

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Molbank 2022, 2022(3), M1418; https://doi.org/10.3390/M1418 - 01 Aug 2022

Viewed by 912

Abstract

Reaction of diphenylmethanol (4) with n-butyllithium and subsequent treatment with selenium resulted in 12H-dibenzo[d,g][1,2,3]triselenocin-12-ol (5) comprising a novel heterocyclic ring system. The title compound 5 was analyzed by ¹H-NMR, ¹³C-NMR [...] Read more.

Reaction of diphenylmethanol (4) with n-butyllithium and subsequent treatment with selenium resulted in 12H-dibenzo[d,g][1,2,3]triselenocin-12-ol (5) comprising a novel heterocyclic ring system. The title compound 5 was analyzed by ¹H-NMR, ¹³C-NMR and HPLC. Additionally, the structure of 5 was confirmed by single crystal X-ray diffraction. Full article

3-Amino-4-(diphenylamino)-1H-2-benzopyran-1-one

Figure 1

Open AccessShort Note

by

Felipe Quiroga-Suavita

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Ricaurte Rodríguez

and

Omar León

Molbank 2022, 2022(3), M1408; https://doi.org/10.3390/M1408 - 14 Jul 2022

Viewed by 965

Abstract

Various synthetic methodologies to obtain 3,4-diaminoisocumarin nucleus have been reported and described. However, mechanistic analysis based on experimental evidence is lacking. Herein, we report the synthesis of the novel 3-amino-4-(diphenylamino)-1H-2-benzopyran-1-one using a two-step methodology with a new mechanistic proposal to explain [...] Read more.

Various synthetic methodologies to obtain 3,4-diaminoisocumarin nucleus have been reported and described. However, mechanistic analysis based on experimental evidence is lacking. Herein, we report the synthesis of the novel 3-amino-4-(diphenylamino)-1H-2-benzopyran-1-one using a two-step methodology with a new mechanistic proposal to explain the formation of the latter based on previously reported precursors and the established conditions. This compound was afforded in 80% yield. Full article

Unexpected Formation of 4-[(1-Carbamoyl-3-oxo-1,3-dihydro-2-benzofuran-1-yl)amino]benzoic Acid from 4-[(3-Amino-1-oxo-1H-2-benzopyran-4-yl)amino]benzoic Acid

Graphical abstract

Open AccessCommunication

by

Ricaurte Rodríguez

,

Felipe Quiroga-Suavita

and

Mónica Yadira Dotor Robayo

Molbank 2022, 2022(3), M1407; https://doi.org/10.3390/M1407 - 12 Jul 2022

Viewed by 914

Abstract

With the aim of obtaining derivatives belonging to 2′,3′-diphenyl-3H-spiro[[2]benzofuran-1,4′-imidazole]-3,5′(3′H)-dione nucleus, we synthesized 4-[(3-amino-1-oxo-1H-2-benzopyran-4-yl)amino]benzoic acid (a 3,4-diaminoisocoumarine derivative), a known precursor of 4-[(1-carbamoyl-3-oxo-1,3-dihydro-2-benzofuran-1-yl)amino]benzoic acid (a phthalide–carboxamide-bearing system) by a novel methodology that we report here. The reaction conditions [...] Read more.

With the aim of obtaining derivatives belonging to 2′,3′-diphenyl-3H-spiro[[2]benzofuran-1,4′-imidazole]-3,5′(3′H)-dione nucleus, we synthesized 4-[(3-amino-1-oxo-1H-2-benzopyran-4-yl)amino]benzoic acid (a 3,4-diaminoisocoumarine derivative), a known precursor of 4-[(1-carbamoyl-3-oxo-1,3-dihydro-2-benzofuran-1-yl)amino]benzoic acid (a phthalide–carboxamide-bearing system) by a novel methodology that we report here. The reaction conditions were optimized to afford the latter in 62% yield. Full article

Synthesis and Evaluation of Self-Assembling Properties of 3-(3,5-Difluoro-3,5-bis((alkoxy)carbonyl)-2,6-dioxoheptan-4-yl)-1-methylpyridin-1-ium Iodides

Graphical abstract

Open AccessCommunication

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Molbank 2022, 2022(3), M1402; https://doi.org/10.3390/M1402 - 06 Jul 2022

Viewed by 1009

Abstract

A synthesis of 3-(3,5-difluoro-3,5-bis((alkoxy)carbonyl)-2,6-dioxoheptan-4-yl)-1-methylpyridin-1-ium iodides with ethyl or nonyl ester groups at positions 3 and 5 was performed. Treatment of the corresponding 2’,6’-dimethyl-1’,4’-dihydro-[3,4’-bipyridine]-3’,5’-dicarboxylates with Selectfluor^® followed by quaternization of pyridine moiety in the obtained dialkyl 2,4-diacetyl-2,4-difluoro-3-(pyridin-3-yl)pentanedioates with methyl iodide gave the desired [...] Read more.

A synthesis of 3-(3,5-difluoro-3,5-bis((alkoxy)carbonyl)-2,6-dioxoheptan-4-yl)-1-methylpyridin-1-ium iodides with ethyl or nonyl ester groups at positions 3 and 5 was performed. Treatment of the corresponding 2’,6’-dimethyl-1’,4’-dihydro-[3,4’-bipyridine]-3’,5’-dicarboxylates with Selectfluor^® followed by quaternization of pyridine moiety in the obtained dialkyl 2,4-diacetyl-2,4-difluoro-3-(pyridin-3-yl)pentanedioates with methyl iodide gave the desired 3-(3,5-difluoro-3,5-bis((alkoxy)carbonyl)-2,6-dioxoheptan-4-yl)-1-methylpyridin-1-ium iodides. This type of compound would be useful as synthetic lipids for further development of the delivery systems. The obtained target compounds were fully characterized by ¹H NMR, ¹⁹F NMR, ¹³C NMR, HRMS, IR and UV data. The estimation of self-assembling properties and characterization of the nanoparticles obtained by ethanol solution injection in an aqueous media were performed by dynamic light scattering (DLS) measurements. DLS measurement data showed that 3-(3,5-difluoro-3,5-bis((nonyloxy)carbonyl)-2,6-dioxoheptan-4-yl)-1-methylpyridin-1-ium iodide created liposomes with the average diameter of 300–400 nm and polydispersity index (PDI) value around 0.30–0.40, while 3-(3,5-difluoro-3,5-bis((ethyloxy)carbonyl)-2,6-dioxoheptan-4-yl)-1-methylpyridin-1-ium iodide formed a heterogeneous sample with PDI value 1, which was not prospective for delivery system development. Full article

Styryl Hemicyanine Dye (E)-3-Methyl-2-(4-thiomorpholinostyryl)benzo[d]thiazol-3-ium Iodide for Nucleic Acids and Cell Nucleoli Visualization

Scheme 1

Open AccessCommunication

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Molbank 2022, 2022(2), M1392; https://doi.org/10.3390/M1392 - 20 Jun 2022

Cited by 1 | Viewed by 1182

Abstract

(E)-3-Methyl-2-(4-thiomorpholinostyryl)benzo[d]thiazol-3-ium iodide 1 was prepared by a convenient and reliable reaction procedure. The slight molar excess of the starting benzaldehyde and the mixture of ethanol: ethyl acetate in the ratio 3:1 as a solvent afforded a pure reaction product. The photophysical [...] Read more.

(E)-3-Methyl-2-(4-thiomorpholinostyryl)benzo[d]thiazol-3-ium iodide 1 was prepared by a convenient and reliable reaction procedure. The slight molar excess of the starting benzaldehyde and the mixture of ethanol: ethyl acetate in the ratio 3:1 as a solvent afforded a pure reaction product. The photophysical properties of the dye in a TE buffer in the absence and presence of double-stranded DNA (dsDNA) were elucidated. The low intrinsic fluorescence of 1 in TE buffer is followed by an increase in the fluorescence after dsDNA binding. The dye is nontoxic for stem cells from apical papilla and the most concentrated fluorescence is detected in the cell nucleoli. Full article

Synthesis, Crystal Structure and Anti-Leukemic Activity of 1,3-Dihydro-1-{1-[4-(4-phenylpyrrolo[1,2-a]quinoxalin-3-yl)benzyl]piperidin-4-yl}-2H-benzimidazol-2-one

Graphical abstract

Open AccessCommunication

by

Jean Guillon

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Solène Savrimoutou

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Sandra Albenque-Rubio

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Noël Pinaud

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Stéphane Moreau

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Vanessa Desplat

Molbank 2022, 2022(1), M1333; https://doi.org/10.3390/M1333 - 09 Feb 2022

Viewed by 1329

Abstract

1,3-Dihydro-1-{1-[4-(4-phenylpyrrolo[1,2-a]quinoxalin-3-yl)benzyl]piperidin-4-yl}-2H-benzimidazol-2-one has been synthesized through a multi-step pathway starting from commercially available 2-nitroaniline. A structure characterization of this new substituted pyrrolo[1,2-a]quinoxaline compound was achieved by using FT-IR, ¹H-NMR, ¹³C-NMR, X-Ray and HRMS spectral analysis. This [...] Read more.

1,3-Dihydro-1-{1-[4-(4-phenylpyrrolo[1,2-a]quinoxalin-3-yl)benzyl]piperidin-4-yl}-2H-benzimidazol-2-one has been synthesized through a multi-step pathway starting from commercially available 2-nitroaniline. A structure characterization of this new substituted pyrrolo[1,2-a]quinoxaline compound was achieved by using FT-IR, ¹H-NMR, ¹³C-NMR, X-Ray and HRMS spectral analysis. This new pyrroloquinoxaline derivative shows an interesting cytotoxic potential against several human leukemia cell lines (HL60, K562 and U937 cells). Full article

CF₃-Bis-TEMPO-Vis: New Visible Light Active Bis-Benzimidazolequinone Alkoxyamine

Graphical abstract

2021

Jump to: 2023, 2022, 2020, 2019

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Molbank 2021, 2021(4), M1300; https://doi.org/10.3390/M1300 - 26 Nov 2021

Viewed by 1668

Abstract

Alkoxyamines of TEMPO usually dissociate thermally at >100 °C; however, room temperature homolysis, activated by visible light, occurs with benzimidazolequinone derivatives. 1,1’-Dimethyl-2,2’-bis{[(2,2,6,6-tetramethylpiperidin-1-yl)oxy]methyl}-6-(trifluoromethyl)-1H,1’H-[5,5’-bibenzimidazole]-4,4’,7,7’-tetrone (CF₃-Bis-TEMPO-Vis) is prepared in a 59% yield through NBS/H₂SO₄ oxidative [...] Read more.

Alkoxyamines of TEMPO usually dissociate thermally at >100 °C; however, room temperature homolysis, activated by visible light, occurs with benzimidazolequinone derivatives. 1,1’-Dimethyl-2,2’-bis{[(2,2,6,6-tetramethylpiperidin-1-yl)oxy]methyl}-6-(trifluoromethyl)-1H,1’H-[5,5’-bibenzimidazole]-4,4’,7,7’-tetrone (CF₃-Bis-TEMPO-Vis) is prepared in a 59% yield through NBS/H₂SO₄ oxidative demethylations of the dimethoxybenzimidazole-benzimidazolequinone precursor with aqueous work up. The alternative basic work up in air gave the epoxide derivative of CF₃-Bis-TEMPO-Vis. Unlike the latter CF₃-epoxide, both alkoxyamine residues are labile under green light (470–600 nm), and the rate of TEMPO release is three times slower than Bis-TEMPO-Vis. Full article

Regioselective Synthesis of 4-Bromo-3-formyl-N-phenyl-5-propylthiophene-2-carboxamide

Graphical abstract

Open AccessCommunication

by

Sukanta Bar

and

Maxwell Israel Martin

Molbank 2021, 2021(4), M1296; https://doi.org/10.3390/M1296 - 16 Nov 2021

Cited by 1 | Viewed by 1643

Abstract

We synthesized 4-bromo-3-formyl-N-phenyl-5-propylthiophene-2-carboxamide by using three successive direct lithiations and a bromination reaction starting from thiophene. All these lithiation reactions were carried out at −78 °C to RT over a period of 1 to 24 h based on the reactivity of [...] Read more.

We synthesized 4-bromo-3-formyl-N-phenyl-5-propylthiophene-2-carboxamide by using three successive direct lithiations and a bromination reaction starting from thiophene. All these lithiation reactions were carried out at −78 °C to RT over a period of 1 to 24 h based on the reactivity of electrophile. This is a four-step protocol starting from thiophene with an overall yield of 47%. Full article

4,7-Bis(1,2,3,4,4a,9a-Hexahydro-9H-carbazol-9-yl)-[1,2,5]oxadiazolo[3,4-d]pyridazine

Graphical abstract

Open AccessShort Note

by

Timofey N. Chmovzh

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Karim S. Gaisin

and

Molbank 2021, 2021(4), M1295; https://doi.org/10.3390/M1295 - 05 Nov 2021

Cited by 1 | Viewed by 1507

Abstract

New donor-acceptor-donor (D-A-D)-type structures are widely used to design effective organic light-emitting diodes (OLEDs). In this communication, 4,7-bis(1,2,3,4,4a,9a-hexahydro-9H-carbazol-9-yl)-[1,2,5]oxadiazolo[3,4-d]pyridazine was obtained in a 65% yield by the treatment of 4,7-dichloro[1,2,5]oxadiazolo[3,4-d]pyridazine 1-oxide with 2,3,4,4a,9,9a-hexahydro-1H-carbazole. The structure of [...] Read more.

New donor-acceptor-donor (D-A-D)-type structures are widely used to design effective organic light-emitting diodes (OLEDs). In this communication, 4,7-bis(1,2,3,4,4a,9a-hexahydro-9H-carbazol-9-yl)-[1,2,5]oxadiazolo[3,4-d]pyridazine was obtained in a 65% yield by the treatment of 4,7-dichloro[1,2,5]oxadiazolo[3,4-d]pyridazine 1-oxide with 2,3,4,4a,9,9a-hexahydro-1H-carbazole. The structure of the newly synthesized compounds was established by means of an elemental analysis, ¹H, ¹³C NMR, IR and UV spectroscopy, and HRMS and LR mass-spectrometry. Full article

6-(Chloromethyl)-N,1-dimethyl-1H-pyrazolo[3,4-d]pyrimidin-4-amine

Graphical abstract

Open AccessShort Note

by

Vladimir A. Ogurtsov

and

Molbank 2021, 2021(4), M1294; https://doi.org/10.3390/M1294 - 01 Nov 2021

Cited by 1 | Viewed by 1555

Abstract

Functionally 4,6-disubstituted 1H-pyrazolo[3,4-d]pyrimidines are important compounds with various pharmacological activities. 1-Substituted 4-chloro-6-(chloromethyl)-1H-pyrazolo[3,4-d]pyrimidines are practically unexplored derivatives in this series. In this paper, it was shown that the nucleophilic substitution of 4-Chloro-6-(chloromethyl)-1-methyl-1H-pyrazolo[3,4-d]pyrimidine [...] Read more.

Functionally 4,6-disubstituted 1H-pyrazolo[3,4-d]pyrimidines are important compounds with various pharmacological activities. 1-Substituted 4-chloro-6-(chloromethyl)-1H-pyrazolo[3,4-d]pyrimidines are practically unexplored derivatives in this series. In this paper, it was shown that the nucleophilic substitution of 4-Chloro-6-(chloromethyl)-1-methyl-1H-pyrazolo[3,4-d]pyrimidine with methylamine produced selectively 4-substituted product, 6-(chloromethyl)-N,1-dimethyl-1H-pyrazolo[3,4-d]pyrimidin-4-amine. The structure of the synthesized compound was established by elemental analysis, high resolution mass-spectrometry, ¹H, ¹³C-NMR, and IR spectroscopy, mass-spectrometry, and X-ray analysis. Full article

Ambient-Temperature Synthesis of (E)-N-(3-(tert-Butyl)-1-methyl-1H-pyrazol-5-yl)-1-(pyridin-2-yl)methanimine

Graphical abstract

Open AccessCommunication

by

Diana Becerra

,

Justo Cobo

and

Juan-Carlos Castillo

Molbank 2021, 2021(3), M1250; https://doi.org/10.3390/M1250 - 07 Jul 2021

Viewed by 1564

Abstract

We report the ambient-temperature synthesis of novel (E)-N-(3-(tert-butyl)-1-methyl-1H-pyrazol-5-yl)-1-(pyridin-2-yl)methanamine 3 in 81% yield by a condensation reaction between 3-(tert-butyl)-1-methyl-1H-pyrazol-5-amine 1 and 2-pyridinecarboxaldehyde 2 in methanol using magnesium sulfate as a drying agent. [...] Read more.

We report the ambient-temperature synthesis of novel (E)-N-(3-(tert-butyl)-1-methyl-1H-pyrazol-5-yl)-1-(pyridin-2-yl)methanamine 3 in 81% yield by a condensation reaction between 3-(tert-butyl)-1-methyl-1H-pyrazol-5-amine 1 and 2-pyridinecarboxaldehyde 2 in methanol using magnesium sulfate as a drying agent. The N-pyrazolyl imine 3 was full characterized by IR, 1D, and 2D NMR spectroscopy, mass spectrometry, and elemental analysis. Full article

(2,3-Dihydro-1H-indol-5-ylmethyl)amine

Figure 1

Open AccessShort Note

by

Vladimir A. Ogurtsov

and

Molbank 2021, 2021(3), M1248; https://doi.org/10.3390/M1248 - 05 Jul 2021

Viewed by 1432

Abstract

New (2,3-dihydro-1H-indol-5-ylmethyl)amine was synthesized from 2-((1-acetylindolin-5-yl)methyl)isoindoline-1,3-dione by simultaneous deprotection of phthalimide and acetyl groups. The structure of the newly synthesized compounds was established by elemental analysis, high resolution mass-spectrometry, ¹H, ¹³C NMR and IR spectroscopy and mass-spectrometry. The resulting [...] Read more.

New (2,3-dihydro-1H-indol-5-ylmethyl)amine was synthesized from 2-((1-acetylindolin-5-yl)methyl)isoindoline-1,3-dione by simultaneous deprotection of phthalimide and acetyl groups. The structure of the newly synthesized compounds was established by elemental analysis, high resolution mass-spectrometry, ¹H, ¹³C NMR and IR spectroscopy and mass-spectrometry. The resulting compound is a convenient intermediate for various disubstituted 1-(indolin-5-yl)methanamines, which may be of interest as substances with useful pharmacological properties. Full article

(E)-4-Oxo-3,4-dihydroquinazoline-2-carbaldehyde Oxime

Graphical abstract

Open AccessShort Note

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Andreas Kourtellaris

and

Molbank 2021, 2021(2), M1233; https://doi.org/10.3390/M1233 - 11 Jun 2021

Viewed by 1481

Abstract

Reaction of 4-oxo-3,4-dihydroquinazoline-2-carbaldehyde with hydroxylamine hydrochloride (1.1 equiv) in the presence of K₂CO₃ (1 equiv) gave (E)-4-oxo-3,4-dihydroquinazoline-2-carbaldehyde oxime (8) in 58% yield. The compound was fully characterized and the conformation of the oxime was supported by single crystal x-ray diffractometry. Full article

3-(tert-Butyl)-N-(4-methoxybenzyl)-1-methyl-1H-pyrazol-5-amine

Graphical abstract

Open AccessShort Note

by

Diana Becerra

,

Hugo Rojas

and

Juan-Carlos Castillo

Molbank 2021, 2021(1), M1196; https://doi.org/10.3390/M1196 - 10 Mar 2021

Cited by 2 | Viewed by 1746

Abstract

We reported an efficient one-pot two-step synthesis of 3-(tert-butyl)-N-(4-methoxybenzyl)-1-methyl-1H-pyrazol-5-amine 3 in good yield by a solvent-free condensation/reduction reaction sequence starting from 3-(tert-butyl)-1-methyl-1H-pyrazol-5-amine 1 and p-methoxybenzaldehyde 2. The one-pot reductive amination proceeded [...] Read more.

We reported an efficient one-pot two-step synthesis of 3-(tert-butyl)-N-(4-methoxybenzyl)-1-methyl-1H-pyrazol-5-amine 3 in good yield by a solvent-free condensation/reduction reaction sequence starting from 3-(tert-butyl)-1-methyl-1H-pyrazol-5-amine 1 and p-methoxybenzaldehyde 2. The one-pot reductive amination proceeded by the formation in situ of the N-(5-pyrazolyl)imine 4 as key synthetic intermediate of other valuable pyrazole derivatives. This methodology is distinguished by its operational easiness, short reaction time, isolation and purification of the aldimine intermediate is not required. The structure of the synthesized N-heterocyclic amine 3 was fully characterized by FTIR-ATR, 1D and 2D NMR experiments, EIMS, and elemental analysis. Full article

Synthesis of 1,5-Disubstituted Tetrazoles in Aqueous Micelles at Room Temperature

Graphical abstract

Open AccessCommunication

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Molbank 2021, 2021(1), M1194; https://doi.org/10.3390/M1194 - 09 Mar 2021

Cited by 2 | Viewed by 1525

Abstract

The ongoing study is a Ugi-azide four-component reaction for the synthesis of 1,5-disubstituted tetrazole(1,5-DST), which involves an aldehyde, different amines, isocyanides, and as azide’s source the Trimethylsilylazide (TMSN₃), in water as solvent using as catalyst the tetradecyltrimethylammonium bromide (TTAB) with a [...] Read more.

The ongoing study is a Ugi-azide four-component reaction for the synthesis of 1,5-disubstituted tetrazole(1,5-DST), which involves an aldehyde, different amines, isocyanides, and as azide’s source the Trimethylsilylazide (TMSN₃), in water as solvent using as catalyst the tetradecyltrimethylammonium bromide (TTAB) with a load of (10% mole), which provides a hydrophobic micellar reaction site. This approach is a step toward a green chemistry reaction of 1,5 disubstituted tetrazole. A serie of 1, 5- disubstituted tetrazole was synthesized by engaging a large substrate scope, leading to yields between 43% and 56%, which are compared afterwards with those obtained with methanol as solvent. The results were confirmed by HRMS, IR, and 1D NMR experiments. Full article

Ethyl 1-Butyl-2-(2-hydroxy-4-methoxyphenyl)-1H-benzo[d]imidazole-5-carboxylate

Figure 1

Open AccessShort Note

by

Reshma Sathyanarayana

and

Boja Poojary

Molbank 2021, 2021(1), M1192; https://doi.org/10.3390/M1192 - 24 Feb 2021

Viewed by 1469

Abstract

Ethyl 4-(butylamino)-3-nitrobenzoate upon “one-pot” nitro-reductive cyclization using sodium dithionite and substituted aldehyde in dimethyl sulphoxide affords ethyl 1-butyl-2-(2-hydroxy-4-methoxyphenyl)-1H-benzo[d]imidazole-5-carboxylate in an 87% yield. The structural characterization was determined by Fourier-transfer infrared spectroscopy (FT-IR), Proton nuclear magnetic resonance (¹H-NMR), [...] Read more.

Ethyl 4-(butylamino)-3-nitrobenzoate upon “one-pot” nitro-reductive cyclization using sodium dithionite and substituted aldehyde in dimethyl sulphoxide affords ethyl 1-butyl-2-(2-hydroxy-4-methoxyphenyl)-1H-benzo[d]imidazole-5-carboxylate in an 87% yield. The structural characterization was determined by Fourier-transfer infrared spectroscopy (FT-IR), Proton nuclear magnetic resonance (¹H-NMR), Carbon-13 nuclear magnetic resonance (¹³C-NMR), mass spectrometry, Ultraviolet-visible(UV-Vis), photoluminescence (PL), thin-film solid emission spectra, cyclic voltammetry (CV) and thermogravimetric (TGA) analysis. Molecular electrostatic potential (MEP) was studied to determine the reactive sites of the molecule. Full article

2-Amino-5-chloro-1H-pyrrole-3,4-dicarbonitrile

Figure 1

Open AccessShort Note

by

and

Molbank 2021, 2021(1), M1191; https://doi.org/10.3390/M1191 - 13 Feb 2021

Cited by 1 | Viewed by 2127

Abstract

The reaction of tetracyanoethylene (TCNE) with HCl (g) in the presence of Sn (1 equiv) and AcOH resulted in 2-amino-5-chloro-1H-pyrrole-3,4-dicarbonitrile in a 74% yield. The compound was fully characterized. Full article

Tetramethyl 1,1′-(2-[{4,5-bis(Methoxycarbonyl)-1H-1,2,3-triazol-1-yl}methyl]-2-[(4-methylphenyl)sulfonamido]propane-1,3-diyl)bis(1H-1,2,3-triazole-4,5-dicarboxylate)

Graphical abstract

Open AccessCommunication

by

Serigne Abdou Khadir Fall

,

Sara Hajib

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Oumaima Karai

,

Younas Aouine

,

Salaheddine Boukhssas

,

Hassane Faraj

and

Anouar Alami

Molbank 2021, 2021(1), M1186; https://doi.org/10.3390/M1186 - 31 Jan 2021

Cited by 1 | Viewed by 1775

Abstract

A new compound tetramethyl 1,1′-(2-[{4,5-bis(methoxycarbonyl)-1H-1,2,3-triazol-1-yl}methyl]-2-[(4-methylphenyl)sulfonamido]propane-1,3-diyl)bis(1H-1,2,3-triazole-4,5-dicarboxylate) (3) was prepared in two steps starting from 2-((4-methylphenyl)sulfonamido)-2-((tosyloxy)methyl)propane-1,3-diylbis(4-methylbenzenesulfonate) (1), with an overall yield of 74%. The key step being the copper-free Huisgen cycloaddition between N [...] Read more.

A new compound tetramethyl 1,1′-(2-[{4,5-bis(methoxycarbonyl)-1H-1,2,3-triazol-1-yl}methyl]-2-[(4-methylphenyl)sulfonamido]propane-1,3-diyl)bis(1H-1,2,3-triazole-4,5-dicarboxylate) (3) was prepared in two steps starting from 2-((4-methylphenyl)sulfonamido)-2-((tosyloxy)methyl)propane-1,3-diylbis(4-methylbenzenesulfonate) (1), with an overall yield of 74%. The key step being the copper-free Huisgen cycloaddition between N-(1,3-diazido-2-(azidomethyl)propan-2-yl)-4-methylbenzenesulfonamide (2) and commercially available dimethyl acetylenedicarboxylate. The chemical structure of compound 3 was determined by IR, 1D and 2D NMR experiments, and elemental analysis. Full article

N-(6-Chloro-3-nitropyridin-2-yl)-5-(1-methyl-1H-pyrazol-4-yl)isoquinolin-3-amine

Graphical abstract

Open AccessShort Note

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Ricardo Augusto Massarico Serafim

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Stefan Laufer

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Matthias Gehringer

Molbank 2021, 2021(1), M1181; https://doi.org/10.3390/M1181 - 18 Jan 2021

Cited by 1 | Viewed by 2373

Abstract

Here we describe the synthesis of N-(6-chloro-3-nitropyridin-2-yl)5-(1-methyl-1H-pyrazol-4-yl)isoquinolin-3-amine via a three-step procedure including a Buchwald–Hartwig arylamination with benzophenone imine and a highly regioselective nucleophilic aromatic substitution. The title compound was analyzed by nuclear magnetic resonance spectroscopy (¹H, ¹³C, [...] Read more.

Here we describe the synthesis of N-(6-chloro-3-nitropyridin-2-yl)5-(1-methyl-1H-pyrazol-4-yl)isoquinolin-3-amine via a three-step procedure including a Buchwald–Hartwig arylamination with benzophenone imine and a highly regioselective nucleophilic aromatic substitution. The title compound was analyzed by nuclear magnetic resonance spectroscopy (¹H, ¹³C, HSQC, HMBC, COSY, DEPT90 and NOESY), high resolution mass spectrometry (ESI-TOF-HRMS) and infrared spectroscopy (ATR-IR) and its structure was confirmed by single crystal X-ray diffraction. The inhibitory potency of the title compound was evaluated for selected kinases harboring a rare cysteine in the hinge region (MPS1, MAPKAPK2 and p70S6Kβ/S6K2). Full article

(S)-1-(Ethoxycarbonyl)ethyl(2R,5S)-2,5-dimethyl-1,3-dioxolan-4-one-2-carboxylate

Figure 1

Open AccessShort Note

by

R. Alan Aitken

,

Oliver E. Haslett

and

Alexandra M. Z. Slawin

Molbank 2021, 2021(1), M1178; https://doi.org/10.3390/M1178 - 02 Jan 2021

Cited by 1 | Viewed by 1650

Abstract

The title compound was obtained in low yield in the condensation of ethyl pyruvate and lactic acid. Its structure is determined by NMR methods and x-ray diffraction and the mechanism for formation of this 1:2 adduct from the initial 1:1 adduct is considered. [...] Read more.

The title compound was obtained in low yield in the condensation of ethyl pyruvate and lactic acid. Its structure is determined by NMR methods and x-ray diffraction and the mechanism for formation of this 1:2 adduct from the initial 1:1 adduct is considered. Full article

Methyl (2E)-3-[3-Benzyl-2-(3-methoxy-3-oxoprop-1-yn-1-yl)-2-(1-naphthyl)imidazolidin-1-yl]acrylate

Figure 1

2020

Jump to: 2023, 2022, 2021, 2019

Open AccessShort Note

by

Alexandra S. Golubenkova

,

Nikita E. Golantsov

and

Leonid G. Voskressensky

Molbank 2021, 2021(1), M1176; https://doi.org/10.3390/M1176 - 30 Dec 2020

Viewed by 1617

Abstract

Compounds with propargylamine moiety are useful synthetic precursors of several important classes of nitrogen-containing heterocycles. The title compound, methyl (2E)-3-[3-benzyl-2-(3-methoxy-3-oxoprop-1-yn-1-yl)-2-(1-naphthyl)imidazolidine-1-yl]acrylate, has been prepared by domino-reaction, employing easily available 1-benzyl-2-(1-naphthyl)-4,5-dihydro-1H-imidazole and methyl propiolate in a high 92% yield. The structure [...] Read more.

Compounds with propargylamine moiety are useful synthetic precursors of several important classes of nitrogen-containing heterocycles. The title compound, methyl (2E)-3-[3-benzyl-2-(3-methoxy-3-oxoprop-1-yn-1-yl)-2-(1-naphthyl)imidazolidine-1-yl]acrylate, has been prepared by domino-reaction, employing easily available 1-benzyl-2-(1-naphthyl)-4,5-dihydro-1H-imidazole and methyl propiolate in a high 92% yield. The structure of title compound was determined using ¹H-NMR, ¹³C-NMR, UV, FT-IR and HRMS (High-Resolution Mass Spectrometry). Full article

4,4′-(Pyrrolo[3,2-b]pyrrole-1,4-diyl)dianiline

Scheme 1

Open AccessShort Note

by

Lorenza Giordano

,

Rafael Ballesteros

and

Rafael Ballesteros-Garrido

Molbank 2020, 2020(4), M1169; https://doi.org/10.3390/M1169 - 23 Nov 2020

Cited by 2 | Viewed by 1663

Abstract

4,4′-(Pyrrolo[3,2-b]pyrrole-1,4-diyl)dianiline was synthesized in one step from benzene-1,4-diamine and ethylene glycol with Pd/Al₂O₃ and ZnO. The title compound was characterized by means of NMR techniques and HRMS mass spectrometry. Full article

6-Nitro-7-tosylquinazolin-4(3H)-one

Scheme 1

Open AccessShort Note

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Nguyet Suong Huyen Dao

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Molbank 2020, 2020(4), M1168; https://doi.org/10.3390/M1168 - 21 Nov 2020

Viewed by 2136

Abstract

Sulfones are important building blocks in the construction of biologically active molecules or functional materials. The sulfonyl functional group in sulfones is so versatile that it can act as either a nucleophile, an electrophile, or a radical in different organic reactions. Recently, quinazoline [...] Read more.

Sulfones are important building blocks in the construction of biologically active molecules or functional materials. The sulfonyl functional group in sulfones is so versatile that it can act as either a nucleophile, an electrophile, or a radical in different organic reactions. Recently, quinazoline sulfones have been used to build asymmetrical ether derivatives as inhibitors of signaling pathways governed by tyrosine kinases and the epidermal growth factor-receptor. In this paper, we report a facile synthesis of a novel quinazoline sulfone, 6-nitro-7-tosylquinazolin-4(3H)-one (III), using the modified protocol from 7-chloro-6-nitroquinazolin-4(3H)-one (I) and sodium p-toluenesulfinate (II). The structure of the title compound III was determined using mass-spectrometry, FT-IR, ¹H-NMR, ¹³C-NMR, DEPT, HSQC (Heteronuclear single quantum coherence), HMBC (Heteronuclear Multiple Bond Correlation Spectroscopy) spectroscopies, and PXRD analysis. Full article

Ethyl (S)-2-Benzamido-5-[(4,6-dimethylpyrimidin-2-yl)amino]pentanoate

Graphical abstract

Open AccessShort Note

by

Mario A. Leyva-Acuña

,

Francisco Delgado-Vargas

,

Gabriela López-Angulo

and

Julio Montes-Avila

Molbank 2020, 2020(4), M1166; https://doi.org/10.3390/M1166 - 13 Nov 2020

Viewed by 1787

Abstract

Pyrimidines are compounds with a wide range of biological activities, and the synthesis of pyrimidine derivatives—useful in chemical and medicinal applications—is important in medicinal chemistry. This work shows the synthesis under microwave irradiation of the novel compound ethyl (S)-2-benzamido-5-[(4,6-dimethylpyrimidin-2-yl)amino]pentanoate (3 [...] Read more.

Pyrimidines are compounds with a wide range of biological activities, and the synthesis of pyrimidine derivatives—useful in chemical and medicinal applications—is important in medicinal chemistry. This work shows the synthesis under microwave irradiation of the novel compound ethyl (S)-2-benzamido-5-[(4,6-dimethylpyrimidin-2-yl)amino]pentanoate (3) from (S)-N-α-benzoyl-l-arginine ethyl ester hydrochloride (1) and acetylacetone (2). Compound 3 was easily purified, obtained in moderate yield (70%), and fully characterized by UV-Vis, FTIR-ATR spectroscopy, ¹H-NMR, ¹³C-NMR, HRMS, and EI-MS. Full article

Sodium N-(3,5-Bis(ethoxycarbonyl)-2,6-dimethyl-1,4-dihydropyridine-4-carbonyl)-l-methioninate

Scheme 1

Open AccessShort Note

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Molbank 2020, 2020(3), M1148; https://doi.org/10.3390/M1148 - 14 Jul 2020

Viewed by 2320

Abstract

The development of the methods for amide bond formation is important for various uses in the laboratory and industrial applications. The compounds combined in their structures 1,4-dihydroisonicotinic acids and amino acids linked with an amide bond can be considered as “privileged structures” due [...] Read more.

The development of the methods for amide bond formation is important for various uses in the laboratory and industrial applications. The compounds combined in their structures 1,4-dihydroisonicotinic acids and amino acids linked with an amide bond can be considered as “privileged structures” due to their broad range of biological activities. Herein, the formation of amide bond between 1,4-dihydroisonicotinic acid and l-methionine is reported. The coupling of l-methionine with pentafluorophenyl active ester of 1,4-dihydroisonicotinic acid appears to be a convenient and effective method for amide bond formation. Sodium N-(3,5-bis(ethoxycarbonyl)-2,6-dimethyl-1,4-dihydropyridine-4-carbonyl)-l-methioninate has been successfully synthesized via a procedure where the key step is amide formation from 5-diethyl 4-(perfluorophenyl) 2,6-dimethyl-1,4-dihydropyridine-3,4,5-tricarboxylate and l-methionine. Sodium salt formation was performed to improve physicochemical properties, such as solubility of the l-methionine-derived 1,4-dihydroisonicotinamide. The obtained target compound was fully characterized by UV, IR, ¹H NMR, ¹³C NMR, MS, and microanalysis. Full article

(2S,3R,6R)-2-[(R)-1-Hydroxyallyl]-4,4-dimethoxy-6-methyltetrahydro-2H-pyran-3-ol

Graphical abstract

Open AccessFeature PaperShort Note

by

Jack Bennett

and

Paul V. Murphy

Molbank 2020, 2020(2), M1140; https://doi.org/10.3390/M1140 - 03 Jun 2020

Viewed by 1818

Abstract

(2S,3R,6R)-2-[(R)-1-Hydroxyallyl]-4,4-dimethoxy-6-methyltetrahydro-2H-pyran-3-ol was isolated in 18% after treating the glucose derived (5R,6S,7R)-5,6,7-tris[(triethylsilyl)oxy]nona-1,8-dien-4-one with (1S)-(+)-10-camphorsulfonic acid (CSA). The one-pot formation of the title compound involved triethylsilyl (TES) [...] Read more.

(2S,3R,6R)-2-[(R)-1-Hydroxyallyl]-4,4-dimethoxy-6-methyltetrahydro-2H-pyran-3-ol was isolated in 18% after treating the glucose derived (5R,6S,7R)-5,6,7-tris[(triethylsilyl)oxy]nona-1,8-dien-4-one with (1S)-(+)-10-camphorsulfonic acid (CSA). The one-pot formation of the title compound involved triethylsilyl (TES) removal, alkene isomerization, intramolecular conjugate addition and ketal formation. The compound was characterized by ¹H and ¹³C NMR spectroscopy, ESI mass spectrometry and IR spectroscopy. NMR spectroscopy was used to establish the product structure, including the conformation of its tetrahydropyran ring. Full article

Synthesis of (R) and (S)-3-Chloro-5-(2,4-dimethylpiperazin-1-yl)-4H-1,2,6-thiadiazin-4-ones

Scheme 1

Open AccessCommunication

by

Christopher R. M. Asquith

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and

Molbank 2020, 2020(2), M1139; https://doi.org/10.3390/M1139 - 01 Jun 2020

Cited by 2 | Viewed by 2075

Abstract

The reaction of 3,5-dichloro-4H-1,2,6-thiadiazin-4-one with (R) and (S)-1,3-dimethylpiperazines (1 equiv), in THF, at ca. 20 °C gives (R) and (S)-3-chloro-5-(2,4-dimethylpiperazin-1-yl)-4H-1,2,6-thiadiazin-4-ones in 70% and 68% yields, respectively. The new compounds were fully characterized. Full article

Methyl 2-(1-methyl-3-oxoisoindolin-1-yl)acetate

Figure 1

Open AccessShort Note

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Molbank 2020, 2020(2), M1131; https://doi.org/10.3390/M1131 - 08 May 2020

Cited by 1 | Viewed by 1874

Abstract

In this work, we report a facile access to a 3,3-disubstituted isoindolinone by means of Krapcho decarboxylation reaction of the respective substituted dimethyl malonate derivative. Good isolated yields were obtained under mild reaction conditions. Full article

2-(Fluoromethyl)-4,7-dimethoxy-1-methyl-1H-benzimidazole

Graphical abstract

Open AccessFeature PaperShort Note

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Molbank 2020, 2020(2), M1129; https://doi.org/10.3390/M1129 - 01 May 2020

Viewed by 2379

Abstract

Selectfluor (1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate)) substitutes the TEMPO free radical with fluorine on 4,7-dimethoxy-1-methyl-2-{[(2,2,6,6-tetramethylpiperidin-1-yl)oxy]methyl}-1H-benzimidazole to give the title compound in a 77% yield. A mechanism is proposed for the formation of this novel methylene fluoride. Full article

Synthesis of (R) and (S)-3-Chloro-5-(3-methylmorpholino)-4H-1,2,6-thiadiazin-4-ones

Graphical abstract

Open AccessCommunication

by

Christopher R. M. Asquith

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and

Molbank 2020, 2020(2), M1128; https://doi.org/10.3390/M1128 - 27 Apr 2020

Cited by 1 | Viewed by 1846

Abstract

Reaction of 3,5-dichloro-4H-1,2,6-thiadiazin-4-one with (R) and (S)-3-methylmorpholines (2 equiv), in THF, at ca. 20 °C gave (R) and (S)-3-chloro-5-(3-methylmorpholino)-4H-1,2,6-thiadiazin-4-ones in 95 and 97% yields, respectively. The new compounds were fully characterized. Full article

2,6-exo-8,12-exo-10-Butyl-13-oxa-3,5-dithia-10-azatetracyclo[5.5.1.0^2,6.0^8,12]tridecane-9,11-dione

Graphical abstract

Open AccessShort Note

by

R. Alan Aitken

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Fiona M. Fotherby

and

Alexandra M. Z. Slawin

Molbank 2020, 2020(2), M1123; https://doi.org/10.3390/M1123 - 02 Apr 2020

Cited by 2 | Viewed by 2234

Abstract

The title compound was obtained in low yield and spectroscopically characterised. Its X-ray structure was compared with the X-ray structures of other crystallographically-characterised 2-unsubstituted 1,3-dithiolanes. Full article

6-Imino-1,2,3,4,8,9,10,11-octahydropyrido[1,2-a]pyrido[1′,2′:1,2]imidazo[4,5-f]benzimidazole-13-one: Synthesis and Cytotoxicity Evaluation

Graphical abstract

Open AccessCommunication

by

Darren Conboy

and

Fawaz Aldabbagh

Molbank 2020, 2020(1), M1118; https://doi.org/10.3390/M1118 - 05 Mar 2020

Cited by 2 | Viewed by 1978

Abstract

The first report of an iminoquinone of imidazo[4,5-f]benzimidazole is described. The 2D-NOESY spectrum of 1,2,3,4,8,9,10,11-octahydropyrido[1,2-a]pyrido[1’,2’:1,2]imidazo[4,5-f]benzimidazol-6-amine was used to confirm the location of the imine moiety at the C-6 position of the title compound. Cytotoxicity data from the National Cancer Institute are included. Full article

Diethyl pyrrole-2,5-dicarboxylate

Figure 1

Open AccessShort Note

by

R. Alan Aitken

,

Charles Bloomfield

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Liam J. R. McGeachie

and

Alexandra M. Z. Slawin

Molbank 2020, 2020(1), M1117; https://doi.org/10.3390/M1117 - 17 Feb 2020

Cited by 1 | Viewed by 1838

Abstract

The title compound was obtained in moderate yield by a new and unexpected base-induced ring contraction from a 1,4-thiazine precursor. Its X-ray structure showing hydrogen bonded dimers was compared with those of other crystallographically characterised 2-acylpyrroles. Full article

1-Phenyl-8-[[4-(pyrrolo[1,2-a]quinoxalin-4-yl)phenyl]methyl]-1,3,8-triazaspiro[4.5]decan-4-one: Synthesis, Crystal Structure and Anti-Leukemic Activity

Figure 1

Open AccessCommunication

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Molbank 2020, 2020(1), M1113; https://doi.org/10.3390/M1113 - 29 Jan 2020

Cited by 4 | Viewed by 2061

Abstract

1-Phenyl-8-[[4-(pyrrolo[1,2-a]quinoxalin-4-yl)phenyl]methyl]-1,3,8-triazaspiro[4.5]decan-4-one has been successfully synthesized via a multi-step pathway starting from 2-nitroaniline. Structure characterization of this original pyrrolo[1,2-a]quinoxaline derivative was achieved by FT-IR, ¹H-NMR, ¹³C-NMR, X-Ray and HRMS spectral analysis. This title compound shows interesting cytotoxic potential [...] Read more.

1-Phenyl-8-[[4-(pyrrolo[1,2-a]quinoxalin-4-yl)phenyl]methyl]-1,3,8-triazaspiro[4.5]decan-4-one has been successfully synthesized via a multi-step pathway starting from 2-nitroaniline. Structure characterization of this original pyrrolo[1,2-a]quinoxaline derivative was achieved by FT-IR, ¹H-NMR, ¹³C-NMR, X-Ray and HRMS spectral analysis. This title compound shows interesting cytotoxic potential against several human leukemia cell lines (K562, HL60, and U937 cells). Full article

Novel One-Pot Synthesis of Methyl 4-Hydroxy-2-thioxo-1,2-dihydroquinoline-3-carboxylate: Synthetic and Crystallographic Studies

Graphical abstract

2019

Jump to: 2023, 2022, 2021, 2020

Open AccessCommunication

by

Sergiy M. Kovalenko

,

Oleksandr G. Drushlyak

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Irina S. Konovalova

,

Illia O. Mariutsa

,

Dmitry V. Kravchenko

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Alexandre V. Ivachtchenko

and

Oleg D. Mitkin

Molbank 2019, 2019(4), M1085; https://doi.org/10.3390/M1085 - 14 Oct 2019

Cited by 2 | Viewed by 1986

Abstract

A new suitable method of synthesis of methyl 4-hydroxy-2-thioxo-1,2-dihydroquinoline-3-carboxylate by condensation of methyl 2-isothiocyanatobenzoate and methyl malonate is described. The structure of the compound both and by-product methyl 2-(methoxycarbonothioylamino)benzoate was confirmed by means of elemental analysis, ¹H NMR, ¹³C NMR, LC/MS [...] Read more.

A new suitable method of synthesis of methyl 4-hydroxy-2-thioxo-1,2-dihydroquinoline-3-carboxylate by condensation of methyl 2-isothiocyanatobenzoate and methyl malonate is described. The structure of the compound both and by-product methyl 2-(methoxycarbonothioylamino)benzoate was confirmed by means of elemental analysis, ¹H NMR, ¹³C NMR, LC/MS and single crystal X-ray diffraction. UV/Vis and IR spectra of compounds are described. The presence of a strong intramolecular hydrogen bond between the hydroxy group and the carbonyl oxygen atom of the ester group in methyl 4-hydroxy-2-thioxo-1,2-dihydroquinoline-3-carboxylate is shown. The crystal structure of product was stabilized through intermolecular hydrogen bonds. Full article

3-{[(2,3-Dichlorophenyl)amino]methyl}-5-(furan-2-ylmethylidene)-1,3-thiazolidine-2,4-dione

Graphical abstract

Open AccessShort Note

by

Nadine Uwabagira

and

Balladka Kunhana Sarojini

Molbank 2019, 2019(4), M1083; https://doi.org/10.3390/M1083 - 03 Oct 2019

Viewed by 1725

Abstract

The compound 3-{[(2,3-Dichlorophenyl)amino]methyl}-5-(furan-2-ylmethylidene)-1,3-thiazolidine-2,4-dione has been designed, synthesized, and screened for its in vitro antibreast cancer activity, using human breast adenocarcinoma cell lines (MCF-7) and in vitro anti-inflammatory activity. By hemolysis assay, it showed that it has a nonhemolytic and nontoxic effect on human [...] Read more.

The compound 3-{[(2,3-Dichlorophenyl)amino]methyl}-5-(furan-2-ylmethylidene)-1,3-thiazolidine-2,4-dione has been designed, synthesized, and screened for its in vitro antibreast cancer activity, using human breast adenocarcinoma cell lines (MCF-7) and in vitro anti-inflammatory activity. By hemolysis assay, it showed that it has a nonhemolytic and nontoxic effect on human blood cell. The title compound 5, subjected to in vitro activities, showed that it is cytotoxic with an IC₅₀ of 42.30 µM and a good anti-inflammatory agent. The docking results against cyclin dependent kinase 2 (CDK2) (PDB ID: 3QQK) gave insights on its inhibitory activity. Full article

4-[(3,5-Dimethyl-1H-pyrazol-1-yl)methyl]-4-methyl-2-phenyl-4,5-dihydrooxazole

Figure 1

Open AccessShort Note

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Molbank 2019, 2019(3), M1074; https://doi.org/10.3390/M1074 - 19 Jul 2019

Cited by 1 | Viewed by 2061

Abstract

The compound, 4-[(3,5-dimethyl-1H-pyrazol-1-yl)methyl]-4-methyl-2-phenyl-4,5-dihydrooxazole 2 was prepared in high yield, through nucleophilic substitution reaction of the O-tosyl oxazoline derivative 1, by heating in dimethyl sulfoxide (DMSO) and in presence of KOH as base. The structure of the synthesized compound was [...] Read more.

The compound, 4-[(3,5-dimethyl-1H-pyrazol-1-yl)methyl]-4-methyl-2-phenyl-4,5-dihydrooxazole 2 was prepared in high yield, through nucleophilic substitution reaction of the O-tosyl oxazoline derivative 1, by heating in dimethyl sulfoxide (DMSO) and in presence of KOH as base. The structure of the synthesized compound was established on the basis of NMR spectroscopy (¹H, ¹³C), MS data and elemental analysis. Full article