Molbank

Open AccessShort Note

5-((8-Hydroxyquinolin-5-yl)diazenyl)-3-methyl-1H-pyrazole-4-carboxylic Acid

by

Ion Burcă

,

Valentin Badea

,

Calin Deleanu

and

Vasile-Nicolae Bercean

Molbank 2021, 2021(2), M1238; https://doi.org/10.3390/M1238 - 16 Jun 2021

Viewed by 1272

Abstract

A new azo compound was prepared via the azo coupling reaction between 4-(ethoxycarbonyl)-3-methyl-1H-pyrazole-5-diazonium chloride and 8-hydroxyquinoline (oxine). The ester functional group of the obtained compound was hydrolyzed and thus a new chemical structure with a carboxylic functional group resulted. The structures [...] Read more.

A new azo compound was prepared via the azo coupling reaction between 4-(ethoxycarbonyl)-3-methyl-1H-pyrazole-5-diazonium chloride and 8-hydroxyquinoline (oxine). The ester functional group of the obtained compound was hydrolyzed and thus a new chemical structure with a carboxylic functional group resulted. The structures of the new compounds were fully characterized by: UV–Vis, FT-IR, 1D and 2D NMR spectroscopy, and HRMS spectrometry. Full article

(This article belongs to the Section Organic Synthesis)

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Scheme 1

Open AccessShort Note

4-Amino-2-(p-tolyl)-7H-chromeno[5,6-d]oxazol-7-one

by

Evangelia-Eirini N. Vlachou

,

Thomas D. Balalas

,

Dimitra J. Hadjipavlou-Litina

and

Konstantinos E. Litinas

Molbank 2021, 2021(2), M1237; https://doi.org/10.3390/M1237 - 15 Jun 2021

Cited by 1 | Viewed by 1257

Abstract

The new 4-amino-2-(p-tolyl)-7H-chromeno[5,6-d]oxazol-7-one was successfully prepared through the Au/TiO₂-catalyzed NaBH₄ activation and chemoselective reduction of the new 4-nitro-2-(p-tolyl)-7H-chromeno[5,6-d]oxazol-7-one. The latter was synthesized by the one-pot tandem reactions of [...] Read more.

The new 4-amino-2-(p-tolyl)-7H-chromeno[5,6-d]oxazol-7-one was successfully prepared through the Au/TiO₂-catalyzed NaBH₄ activation and chemoselective reduction of the new 4-nitro-2-(p-tolyl)-7H-chromeno[5,6-d]oxazol-7-one. The latter was synthesized by the one-pot tandem reactions of 6-hydroxy-5,7-dinitrocoumarin with p-tolylmethanol under Au/TiO₂ catalysis. The dinitrocoumarin was obtained by the nitration of 6-hydroxycoumarin with cerium ammonium nitrate (CAN). The structure of the synthesized compounds was confirmed by FT-IR, HR-MS, ¹H-NMR and ¹³C-NMR analysis. Preliminary biological tests show low anti-lipid peroxidation activity for the title compound. Full article

(This article belongs to the Special Issue Nitrogen-Containing Molecules: Natural and Synthetic Products Including Coordination Compounds)

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Scheme 1

Open AccessShort Note

(E)-2-(2-Oxo-4-phenylbut-3-en-1-yl)benzo[d]thiazole-3(2H)-carboxylates

by

Yordan Stremski

and

Stela Statkova-Abeghe

Molbank 2021, 2021(2), M1236; https://doi.org/10.3390/M1236 - 13 Jun 2021

Cited by 1 | Viewed by 1847

Abstract

An convenient one-pot approach for the synthesis of new (E)-2-(2-oxo-4-phenylbut-3-en-1-yl)benzo[d]thiazole-3(2H)-carboxylates is demonstrated. The method is based on a three-component reaction of benzylideneacetone with electrophilic N-alkoxycarbonylbenzothiazolium species formed in situ. The newly synthesized compounds were fully [...] Read more.

An convenient one-pot approach for the synthesis of new (E)-2-(2-oxo-4-phenylbut-3-en-1-yl)benzo[d]thiazole-3(2H)-carboxylates is demonstrated. The method is based on a three-component reaction of benzylideneacetone with electrophilic N-alkoxycarbonylbenzothiazolium species formed in situ. The newly synthesized compounds were fully characterized by 1D ¹H, ¹³C- NMR, IR and MS. Full article

(This article belongs to the Section Organic Synthesis)

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Graphical abstract

Open AccessArticle

Ag(I) Complexes of Imine Derivatives of Unexpected 2-Thiophenemethylamine Homo-Coupling and Bis-(E)-N-(furan-2-ylmethyl)-1-(quinolin-2-yl)methanimine

by

Adesola A. Adeleke

,

Sizwe J. Zamisa

and

Bernard Omondi

Molbank 2021, 2021(2), M1235; https://doi.org/10.3390/M1235 - 12 Jun 2021

Cited by 3 | Viewed by 1734

Abstract

Imines are fundamental organic compounds used as synthetic intermediates and as ligands in coordination chemistry. They are also found to be important pharmacophores in various bioactive compounds. In this report, two Schiff bases were prepared using the traditional condensation of 4-pyridinecarboxaldehyde with 2-thiophenemethylamine [...] Read more.

Imines are fundamental organic compounds used as synthetic intermediates and as ligands in coordination chemistry. They are also found to be important pharmacophores in various bioactive compounds. In this report, two Schiff bases were prepared using the traditional condensation of 4-pyridinecarboxaldehyde with 2-thiophenemethylamine and 2-quinolinecarboxaldehyde with furfurylamine to form (E)-1-(pyridin-4-yl)-N-(thiophen-2-ylmethyl)methanimine (L₁) and (E)-N-(furan-2-ylmethyl)-1-(quinolin-2-yl)methanimine (L₂) respectively. L₁ and L₂ were complexed with silver perchlorate in 2:1 [M:L] stoichiometry to obtain complexes 1 and 2, respectively. The crystal structures of 1 and 2 were unequivocally determined by single-crystal X-ray diffraction analysis. The resulting structures revealed 2 to be a four-coordinate as expected. In contrast, an unexpected chemoselective hydrolytic cleavage of one mole of the (CH=N) imine ligands occurred in complex 2 and, further, the amines (thiophenemethylamine) homo-coupled to form a new imine ligand derivative in situ (L_1a) before coordinating to the Ag(I) center along with L₁. This observation described an alternative synthetic route to be explored to synthesize a diverse range of imine derivatives, which involves the Ag(I)-promoted homo-coupling of amines. Herein, the crystal structures of Ag(I) complexes of pyridinyl [Ag(L₁)(L_1a)]ClO₄ (1) and quinolinyl [Ag(L₂)₂]ClO₄ (2) Schiff bases are presented. Full article

(This article belongs to the Section Organic Synthesis)

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Graphical abstract

Open AccessCommunication

Bioactive Antidiabetic Flavonoids from the Stem Bark of Cordia dichotoma Forst.: Identification, Docking and ADMET Studies

by

Nazim Hussain

,

Bibhuti Bhushan Kakoti

,

Mithun Rudrapal

,

Khomendra Kumar Sarwa

,

Ismail Celik

,

Emmanuel Ifeanyi Attah

,

Shubham Jagadish Khairnar

,

Soumya Bhattacharya

,

Ranjan Kumar Sahoo

and

Sanjay G. Walode

Molbank 2021, 2021(2), M1234; https://doi.org/10.3390/M1234 - 11 Jun 2021

Cited by 14 | Viewed by 2099

Abstract

Cordia dichotoma Forst. (F. Boraginaceae) has been traditionally used for the management of a variety of human ailments. In our earlier work, the antidiabetic activity of methanolic bark extract of C. dichotoma (MECD) has been reported. In this paper, two flavonoid molecules were [...] Read more.

Cordia dichotoma Forst. (F. Boraginaceae) has been traditionally used for the management of a variety of human ailments. In our earlier work, the antidiabetic activity of methanolic bark extract of C. dichotoma (MECD) has been reported. In this paper, two flavonoid molecules were isolated (by column chromatography) and identified (by IR, NMR and mass spectroscopy/spectrometry) from the MECD with an aim to investigate their antidiabetic effectiveness. Molecular docking and ADMET studies were carried out using AutoDock Vina software and Swiss ADME online tool, respectively. The isolated flavonoids were identified as 3,5,7,3′,4′-tetrahydroxy-4-methoxyflavone-3-O-l-rhamnopyranoside and 5,7,3′-trihydroxy-4-methoxyflavone-7-O-l-rhamnopyranoside (quercitrin). Docking and ADMET studies revealed the promising binding affinity of flavonoid molecules for human lysosomal α-glucosidase and human pancreatic α-amylase with acceptable ADMET properties. Based on computational studies, our study reports the antidiabetic potential of the isolated flavonoids with predictive pharmacokinetics profile. Full article

(This article belongs to the Special Issue Synthesis of Flavonoids or Other Nature-Inspired Small Molecules)

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Figure 1

Open AccessShort Note

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

by

Andreas S. Kalogirou

,

Andreas Kourtellaris

and

Panayiotis A. Koutentis

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

Viewed by 1373

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

(This article belongs to the Collection Heterocycle Reactions)

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Graphical abstract

Open AccessShort Note

Kokosanolide D: A New Tetranortriterpenoid from Fruit Peels of Lansium domesticum Corr. cv Kokossan

by

,

,

,

,

,

and

Molbank 2021, 2021(2), M1232; https://doi.org/10.3390/M1232 - 10 Jun 2021

Cited by 5 | Viewed by 1783

Abstract

A novel tetranortriterpenoid named kokosanolide D has been isolated from fruit peels of Lansium domesticum. The structure of kokosanolide D was elucidated primarily on the basis of spectroscopic data including infrared, 1D and 2D-NMR, as well as high resolution mass spectroscopy analysis [...] Read more.

A novel tetranortriterpenoid named kokosanolide D has been isolated from fruit peels of Lansium domesticum. The structure of kokosanolide D was elucidated primarily on the basis of spectroscopic data including infrared, 1D and 2D-NMR, as well as high resolution mass spectroscopy analysis and comparison with related compounds previously reported. Full article

(This article belongs to the Special Issue Synthesis of Flavonoids or Other Nature-Inspired Small Molecules)

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Graphical abstract

Open AccessShort Note

(R,S)-2-{[4-(4-Methoxyphenyl)-5-phenyl-4H-1,2,4-triazol-3-yl] thio}-1-phenyl-1-ethanol

by

Flavius-Gabriel Wurfer

and

Valentin Badea

Molbank 2021, 2021(2), M1231; https://doi.org/10.3390/M1231 - 08 Jun 2021

Viewed by 1433

Abstract

4-(4-Methoxyphenyl)-5-phenyl--4H-1,2,4-triazole-3-thiol (4) was alkylated to 2-{[4-(-4-methoxyphenyl)-5-phenyl-4H-1,2,4-triazol-3-yl]thio}-1-phenylethan-1-one (5) in alkaline conditions using 2-bromo-1-phenylethanone. The alkylated compound (5) was reduced at the carbonyl group to the corresponding racemic secondary alcohol with an asymmetric carbon, ( [...] Read more.

4-(4-Methoxyphenyl)-5-phenyl--4H-1,2,4-triazole-3-thiol (4) was alkylated to 2-{[4-(-4-methoxyphenyl)-5-phenyl-4H-1,2,4-triazol-3-yl]thio}-1-phenylethan-1-one (5) in alkaline conditions using 2-bromo-1-phenylethanone. The alkylated compound (5) was reduced at the carbonyl group to the corresponding racemic secondary alcohol with an asymmetric carbon, (R,S)-2-{[4-(4-methoxyphenyl)-5-phenyl-4H-1,2,4-triazol-3-yl]thio}-1-phenyl-1-ethanol (6). Both synthesized compounds, ketone (5) and secondary alcohol (6), are new and have not been reported yet in the literature. All the synthesized compounds were characterized by IR, 1D and 2D NMR ¹H-¹H, ¹H-¹³C and ¹H-¹⁵N-NMR spectroscopy and by elemental analysis. Full article

(This article belongs to the Section Organic Synthesis)

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Graphical abstract

Open AccessShort Note

Crystal Structure of 9-Dibenzylsulfide-7,8-dicarba-nido-undecaborane 9-Bn₂S-7,8-C₂B₉H₁₁

by

,

,

and

Molbank 2021, 2021(2), M1230; https://doi.org/10.3390/M1230 - 07 Jun 2021

Viewed by 1483

Abstract

The crystal structure of 9-dibenzylsulfide-7,8-dicarba-nido-undecaborane 9-Bn₂S-7,8-C₂B₉H₁₁ was determined by a single-crystal X-ray diffraction. One of the benzyl groups is located above the open face of the carborane cage with a short H···H distance (2.29 [...] Read more.

The crystal structure of 9-dibenzylsulfide-7,8-dicarba-nido-undecaborane 9-Bn₂S-7,8-C₂B₉H₁₁ was determined by a single-crystal X-ray diffraction. One of the benzyl groups is located above the open face of the carborane cage with a short H···H distance (2.29 and 2.71 Å for two symmetrically independent molecules) between the BHB-bridging hydrogen atom of the carborane fragment and the ortho-CH group of the aromatic ring. Topological analysis has revealed the existence of a critical bond point with a calculated energy of −0.8 kcal/mol in accordance with an X-ray diffraction molecular geometry. The crystal packing analysis revealed that this benzyl group is also involved in π-stacking interactions, while another benzyl group participates in numerous weak H···π, H···H and van der Waals interactions. Full article

(This article belongs to the Section Structure Determination)

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Figure 1

Open AccessShort Note

7-Bromo-[1,2,5]selenadiazolo[3,4-d]pyridazin-4(5H)-one

by

Timofey N. Chmovzh

and

Oleg A. Rakitin

Molbank 2021, 2021(2), M1229; https://doi.org/10.3390/M1229 - 05 Jun 2021

Cited by 1 | Viewed by 1413

Abstract

New heterocyclic systems containing 1,2,5-chalcogenadiazoles are of great interest for the creation of organic photovoltaic materials and biologically active compounds. In this communication, 3,6-dibromopyridazine-4,5-diamine was investigated in reaction with selenium dioxide in order to obtain 4,7-dibromo-[1,2,5]selenadiazolo[3,4-d]pyridazine. We found that 7-bromo-[1,2,5]selenadiazolo[3,4-d [...] Read more.

New heterocyclic systems containing 1,2,5-chalcogenadiazoles are of great interest for the creation of organic photovoltaic materials and biologically active compounds. In this communication, 3,6-dibromopyridazine-4,5-diamine was investigated in reaction with selenium dioxide in order to obtain 4,7-dibromo-[1,2,5]selenadiazolo[3,4-d]pyridazine. We found that 7-bromo-[1,2,5]selenadiazolo[3,4-d]pyridazin-4(5H)-one, the first representative of the new heterocyclic system, was isolated as a hydrolysis product of the corresponding 4,7-dibromoderivative. The structure of the newly synthesized compound was established by means of elemental analysis, high-resolution mass spectrometry, ¹H, ¹³C NMR, IR and UV spectroscopy, and mass spectrometry. Full article

(This article belongs to the Special Issue Heteroatom Rich Organic Heterocycles)

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Scheme 1

Open AccessShort Note

1-Methyl-8-phenyl-1,3-diazaspiro[4.5]decane-2,4-dione

by

Vasiliki Pardali

,

Sotirios Katsamakas

,

Erofili Giannakopoulou

and

Grigoris Zoidis

Molbank 2021, 2021(2), M1228; https://doi.org/10.3390/M1228 - 04 Jun 2021

Cited by 1 | Viewed by 1395

Abstract

A simple, fast and cost-effective three-step synthesis of 1-methyl-8-phenyl-1,3-diazaspiro[4.5]decane-2,4-dione has been developed. The reactions described herein proceed readily, with high yields and no further purification. Therefore, the proposed method, with an overall yield of 60%, offers a facile pathway to the synthesis of [...] Read more.

A simple, fast and cost-effective three-step synthesis of 1-methyl-8-phenyl-1,3-diazaspiro[4.5]decane-2,4-dione has been developed. The reactions described herein proceed readily, with high yields and no further purification. Therefore, the proposed method, with an overall yield of 60%, offers a facile pathway to the synthesis of N-1 monosubstituted spiro carbocyclic imidazolidine-2,4-diones (hydantoins), which constitute a privileged class of heterocyclic scaffolds with pharmacological interest. Full article

(This article belongs to the Special Issue Nitrogen-Containing Molecules: Natural and Synthetic Products Including Coordination Compounds)

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Graphical abstract

Open AccessShort Note

4-[(2,4-Dichlorophenyl)carbamoyl]butanoic Acid

by

,

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,

,

,

and

Molbank 2021, 2021(2), M1227; https://doi.org/10.3390/M1227 - 04 Jun 2021

Cited by 3 | Viewed by 1391

Abstract

The synthesis and spectroscopic characterization of the glutaric acid-amide derivative, 2,4-Cl₂C₆H₃N(H)C(=O)(CH₂)₃C(=O)OH (1), are described. The X-ray crystal structure determination of (1) shows the backbone of the molecule to be [...] Read more.

The synthesis and spectroscopic characterization of the glutaric acid-amide derivative, 2,4-Cl₂C₆H₃N(H)C(=O)(CH₂)₃C(=O)OH (1), are described. The X-ray crystal structure determination of (1) shows the backbone of the molecule to be kinked about the methylene-C–N(amide) bond as seen in the C(p)–N–C(m)–C(m) torsion angle of −157.0(2)°; m = methylene and p = phenyl. An additional twist in the molecule is noted between the amide and phenyl groups as reflected in the C(m)–N–C(p)–C(p) torsion angle of 138.2(2)°. The most prominent feature of the molecular packing is the formation of supramolecular tapes assembled through carboxylic acid-O–H^…O(carbonyl) and amide-N–H^…O(amide) hydrogen bonding. Full article

(This article belongs to the Section Structure Determination)

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Graphical abstract

Open AccessShort Note

(E)-1-(3,4-Dimethoxyphenyl)-2-methyl-3-phenylprop-2-en-1-one: A P-Type Acid-Stable Photochromic α-Methylchalcone

by

Banu Öngel

,

Jörg M. Neudörfl

and

Axel G. Griesbeck

Molbank 2021, 2021(2), M1226; https://doi.org/10.3390/M1226 - 04 Jun 2021

Viewed by 1653

Abstract

The α-methylated chalcone 3 with an electron-donor substituted A-aryl ring and an unsubstituted B-phenyl ring was synthesized by base-catalyzed aldehyde/acetophenone condensation. Compound 3 can be photo-switched from E→Z by irradiation with long-wavelength light λ > 350 nm, whereas irradiation with shorter wavelengths leads [...] Read more.

The α-methylated chalcone 3 with an electron-donor substituted A-aryl ring and an unsubstituted B-phenyl ring was synthesized by base-catalyzed aldehyde/acetophenone condensation. Compound 3 can be photo-switched from E→Z by irradiation with long-wavelength light λ > 350 nm, whereas irradiation with shorter wavelengths leads to photo-stationary states (PSS) with lower amounts of the Z-isomer. The limiting wavelength for fully equilibrated E⮀Z (PSS = 1) can be achieved around 240 nm. The stability of both E- and Z-isomers at the wavelength-dependent PSS under UV-irradiation between 250 and 350 nm is remarkably high as observed from UV and NMR spectroscopy. Compound 3 is fatigue resistant even after more than 10 days continuous irradiation and is also oxygenation-stable under singlet oxygen sensitization conditions. In remarkable contrast to many other α-methylated chalcones, no change in the E/Z-ratio was detected when PSS samples were treated with Broensted acids. The negative photochromic E→Z switch of 3 is accompanied by a conformational switch from the E-form in its preferred s-trans conformation to the Z-form in a distorted s-cis conformation (E_s-c→Z_s-t). Full article

(This article belongs to the Section Organic Synthesis)

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Figure 1

Open AccessShort Note

2-{3,5-Bis-[5-(3,4-didodecyloxyphenyl)thien-2-yl]phenyl}-5-(3,4-didodecyloxyphenyl)thiophene

by

Matthias Jochem

and

Heiner Detert

Molbank 2021, 2021(2), M1225; https://doi.org/10.3390/M1225 - 01 Jun 2021

Viewed by 1256

Abstract

Star-shaped compounds are widely recognized as emerging materials for optical and electrical applications and as scaffolds of discotic liquid crystal. While the C₃-symmetrical tri(phenylthienyl)benzene is the core for several electroopotical materials, no liquid crystal with this scaffold has yet been reported. [...] Read more.

Star-shaped compounds are widely recognized as emerging materials for optical and electrical applications and as scaffolds of discotic liquid crystal. While the C₃-symmetrical tri(phenylthienyl)benzene is the core for several electroopotical materials, no liquid crystal with this scaffold has yet been reported. Acid-catalyzed cyclocondensation of bromoacetylthiophene gives a C₃-symmetrical star, threefold Suzuki coupling results in extension of the conjugated system. With 3,4-didodecylocyphenyl boronic acid, a star with a large rigid conjugated system and flexible aliphatic periphery is obtained. Differentials scanning calorimetry and polarized optical microscopy reveal an enantiotropic mesophase from 66 °C to 106 °C. Full article

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Figure 1

Open AccessCommunication

1,2-Bis(4-(1,3-dioxolan-2-yl)phenyl)diazene Oxide

by

Ekaterina S. Spesivaya

,

Ida A. Lupanova

,

Dzhamilya N. Konshina

and

Valery V. Konshin

Molbank 2021, 2021(2), M1224; https://doi.org/10.3390/M1224 - 01 Jun 2021

Cited by 2 | Viewed by 1446

Abstract

A simple approach to synthesizing 1,2-bis(4-(1,3-dioxolan-2-yl)phenyl)diazene oxide was developed in this study, based on glucose as an eco-friendly reductant. Full article

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Open AccessShort Note

Diethyl (2-(4-Phenyl-1H-1,2,3-triazol-1-yl)benzyl) Phosphate

by

Gabriel P. da Costa

,

Diego Alves

and

Márcio S. Silva

Molbank 2021, 2021(2), M1223; https://doi.org/10.3390/M1223 - 01 Jun 2021

Viewed by 1290

Abstract

Here we describe a full structural elucidation of the diethyl (2-(4-phenyl-1H-1,2,3-triazol-1-yl)benzyl) phosphate. This compound is a common by-product present in the synthetic protocols to access the α-hydroxy phosphonate compounds through of a Phospha-Brook rearrangement. Thus, a complete NMR structural characterization [...] Read more.

Here we describe a full structural elucidation of the diethyl (2-(4-phenyl-1H-1,2,3-triazol-1-yl)benzyl) phosphate. This compound is a common by-product present in the synthetic protocols to access the α-hydroxy phosphonate compounds through of a Phospha-Brook rearrangement. Thus, a complete NMR structural characterization of this rearrangement by-product was performed by ¹H, ¹³C{¹H}, ³¹P{¹H}, COSY, HSQC, and HMBC NMR experiments. Additionally, we have demonstrated that the ¹H-³¹P HMBC is a 2D heteroatom NMR experiment which combines the simple identification by ³¹P chemical shift with the detection sensitivity by ¹H spectrum in a practical procedure. Full article

(This article belongs to the Section Structure Determination)

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Figure 1

Open AccessCommunication

Synthesis and Cytotoxic Potential of 3-Oxo-19β-trifluoroacetoxy-18αH-oleane-28-oic Acid

by

Elmira F. Khusnutdinova

,

Alexander I. Poptsov

and

Oxana B. Kazakova

Molbank 2021, 2021(2), M1222; https://doi.org/10.3390/M1222 - 01 Jun 2021

Cited by 1 | Viewed by 1380

Abstract

Trifluoroacetic acid-promoted Wagner-Meerwein rearrangement of betulonic acid carboxamide led to the formation of the expected 19β,28-lactam along with a new germanicane-type 3-oxo-19β-trifluoroacetoxy-18αH-oleane-28-oic acid. The structure of this triterpenoid was confirmed by 2D NMR analyses. A primary evaluation of biological potency revealed [...] Read more.

Trifluoroacetic acid-promoted Wagner-Meerwein rearrangement of betulonic acid carboxamide led to the formation of the expected 19β,28-lactam along with a new germanicane-type 3-oxo-19β-trifluoroacetoxy-18αH-oleane-28-oic acid. The structure of this triterpenoid was confirmed by 2D NMR analyses. A primary evaluation of biological potency revealed an anticancer activity with GI₅₀ < 5 μM against leukemia, colon cancer, breast cancer, and prostate cancer cell lines, while the parent compounds were not active. Full article

(This article belongs to the Section Natural Products)

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Graphical abstract

Open AccessShort Note

2-Cyclopropyl-6-phenyl-2,3-dihydrothieno[3,2-d][1,3,2]diazaborinin-4(1H)-one

by

Romain Mustière

,

Patrice Vanelle

and

Nicolas Primas

Molbank 2021, 2021(2), M1221; https://doi.org/10.3390/M1221 - 01 Jun 2021

Viewed by 1613

Abstract

As part of our ongoing scaffold hopping work on antimalarial 2-aminothieno[3,2-d]pyrimidin-4-one scaffold, we explored the dihydrothieno[3,2-d][1,3,2]diazaborinin-4(1H)-one as a potential new antimalarial series. Using conditions found in the literature, we obtained 2-cyclopropyl-6-phenyl-2,3-dihydrothieno[3,2-d][1,3,2]diazaborinin-4(1H)-one with 93% [...] Read more.

As part of our ongoing scaffold hopping work on antimalarial 2-aminothieno[3,2-d]pyrimidin-4-one scaffold, we explored the dihydrothieno[3,2-d][1,3,2]diazaborinin-4(1H)-one as a potential new antimalarial series. Using conditions found in the literature, we obtained 2-cyclopropyl-6-phenyl-2,3-dihydrothieno[3,2-d][1,3,2]diazaborinin-4(1H)-one with 93% yield through a simple treatment. It was then characterized by NMR (¹H and ¹³C) and HRMS. Given the structure of this molecule, its aqueous stability was assessed to determine its suitability for biological tests. To our knowledge, this is the first dihydrothieno[3,2-d][1,3,2]diazaborinin-4(1H)-one described. Full article

(This article belongs to the Section Organic Synthesis)

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Figure 1

Open AccessShort Note

(2S*,4S*)-4-[(E)-(2,2-Dimethylhydrazono)methyl]-6-methoxy-4-methyl-2-[(E)-styryl]-1,2,3,4-tetrahydroquinoline

by

José Clerigué

,

M. Teresa Ramos

and

J. Carlos Menéndez

Molbank 2021, 2021(2), M1220; https://doi.org/10.3390/M1220 - 01 Jun 2021

Viewed by 1417

Abstract

The Povarov reaction of p-anisidine, cinnamaldehyde and methacrolein dimethylhydrazone afforded a 1,2,3,4-tetrahydroquinoline derivative bearing 2-styryl, 4-methyl and 4-dimethylhydrazono substituents in a fully diastereoselective fashion. This is the first example of the combination of a type I aza-vinylogous Povarov reaction and a type [...] Read more.

The Povarov reaction of p-anisidine, cinnamaldehyde and methacrolein dimethylhydrazone afforded a 1,2,3,4-tetrahydroquinoline derivative bearing 2-styryl, 4-methyl and 4-dimethylhydrazono substituents in a fully diastereoselective fashion. This is the first example of the combination of a type I aza-vinylogous Povarov reaction and a type II vinylogous Povarov reaction in the same process. Full article

(This article belongs to the Special Issue Quinoline, Derivatives and Applications)

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Graphical abstract

Open AccessCommunication

Ammonium Salts of 5-(3-Chromenyl)-5H-chromeno[2,3-b]pyridines

by

Yuliya E. Ryzhkova

,

Artem N. Fakhrutdinov

and

Michail N. Elinson

Molbank 2021, 2021(2), M1219; https://doi.org/10.3390/M1219 - 30 May 2021

Cited by 2 | Viewed by 1627

Abstract

The ammonium salts of many drugs have significantly improved the solubility and, accordingly, the bioavailability of medicinal substances in the human body. 5-(4-Hydroxy-2-oxo-2H-chromen-3-yl)-5H-chromeno[2,3-b]pyridines are potential NPY1R ligands, which are attractive for antiobesity treatment. Ammonium salts of 5 [...] Read more.

The ammonium salts of many drugs have significantly improved the solubility and, accordingly, the bioavailability of medicinal substances in the human body. 5-(4-Hydroxy-2-oxo-2H-chromen-3-yl)-5H-chromeno[2,3-b]pyridines are potential NPY1R ligands, which are attractive for antiobesity treatment. Ammonium salts of 5H-chromeno[2,3-b]pyridines were previously unknown. In this communication, it was found that the four-component reaction of salicylaldehyde, 2-aminoprop-1-ene-1,1,3-tricarbonitrile, 4-Hydroxy-2H-chromen-2-one and amines results in the formation of ammonium salts of 5-(3-chromenyl)-5H-chromeno[2,3-b]pyridines. The structure of these previously unknown compounds was confirmed by means of ¹H, ¹³C NMR and IR spectroscopy, mass spectrometry and elemental analysis. Full article

(This article belongs to the Section Organic Synthesis)

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5-Ethoxy-1-(4-methoxyphenyl)-5-methyl-3-phenylimidazolidine-2,4-dione

by

Xabier del Corte

,

Adrián López-Francés

,

Edorta Martinez de Marigorta

,

Francisco Palacios

and

Javier Vicario

Molbank 2021, 2021(2), M1218; https://doi.org/10.3390/M1218 - 28 May 2021

Viewed by 1461

Abstract

The title compound is a hydantoin derivative that has been synthesized through a three-component reaction of ethyl pyruvate, p-anisidine and phenyl isocyanate. This paper provides a comprehensive spectral dataset for the title compound, including ¹H and ¹³C{¹H} NMR, [...] Read more.

The title compound is a hydantoin derivative that has been synthesized through a three-component reaction of ethyl pyruvate, p-anisidine and phenyl isocyanate. This paper provides a comprehensive spectral dataset for the title compound, including ¹H and ¹³C{¹H} NMR, IR, HRMS, and X-ray crystallography analyses. A tentative mechanism comprising two complementary pathways is provided based on additional experiments with the preformed intermediates. Full article

(This article belongs to the Section Organic Synthesis)

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Dichloro(η⁶-p-cymene)(P,P-diphenyl-N-propyl-phosphinous amide-κP)ruthenium(II)

by

Rebeca González-Fernández

,

Pascale Crochet

and

Victorio Cadierno

Molbank 2021, 2021(2), M1217; https://doi.org/10.3390/M1217 - 28 May 2021

Viewed by 1292

Abstract

The title compound, i.e., [RuCl₂(η⁶-p-cymene)(PPh₂NHⁿPr)] (2), was obtained in a 71% yield by reacting a toluene solution of the chlorophosphine complex [RuCl₂(η⁶-p-cymene)(PPh₂ [...] Read more.

The title compound, i.e., [RuCl₂(η⁶-p-cymene)(PPh₂NHⁿPr)] (2), was obtained in a 71% yield by reacting a toluene solution of the chlorophosphine complex [RuCl₂(η⁶-p-cymene)(PPh₂Cl)] (1) with two equivalents of n-propylamine at room temperature. The aminophosphine complex 2 was characterized by elemental analysis, multinuclear NMR (³¹P{¹H}, ¹H and ¹³C{¹H}) and IR spectroscopy. In addition, its catalytic behavior in the hydration of benzonitrile was briefly explored. Full article

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Trans-[Cu(quin)₂(EtOH)₂]

by

Nina Podjed

,

Jerneja Črepinšek

and

Barbara Modec

Molbank 2021, 2021(2), M1216; https://doi.org/10.3390/M1216 - 27 May 2021

Viewed by 1663

Abstract

Trans-[Cu(quin)₂(EtOH)₂] (1) was synthesized as part of our study on copper(II) quinaldinate complexes with various O- and N-donor ligands. Compound 1 was characterized by infrared spectroscopy, thermal analysis and X-ray structure analysis. Full article

(This article belongs to the Section Structure Determination)

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Open AccessCommunication

Synthesis, Characterization, and DFT Studies of N-(3,5-Bis(trifluoromethyl)benzyl)stearamide

by

Angélica Salinas-Torres

,

,

,

and

Molbank 2021, 2021(2), M1215; https://doi.org/10.3390/M1215 - 25 May 2021

Viewed by 1320

Abstract

The novel N-(3,5-bis(trifluoromethyl)benzyl)stearamide 3 was prepared in moderate yield by a solventless direct amidation reaction of stearic acid 1 with 3,5-bis(trifluoromethyl)benzylamine 2 at 140 °C for 24 h under metal- and catalyst-free conditions. This practical method was conducted [...] Read more.

The novel N-(3,5-bis(trifluoromethyl)benzyl)stearamide 3 was prepared in moderate yield by a solventless direct amidation reaction of stearic acid 1 with 3,5-bis(trifluoromethyl)benzylamine 2 at 140 °C for 24 h under metal- and catalyst-free conditions. This practical method was conducted in air without any special treatment or activation. The fatty acid amide 3 was fully characterized by IR, UV–Vis, 1D and 2D NMR spectroscopy, mass spectrometry, and elemental analysis. Moreover, molecular electrostatic potential studies, determination of quantum descriptors, fundamental vibrational frequencies, and intensity of vibrational bands were computed by density functional theory (DFT) using the B3LYP method with 6-311+G(d,p) basis set in gas phase. Simulation of the infrared spectrum using the results of these calculations led to good agreement with the observed spectral patterns. Full article

(This article belongs to the Section Organic Synthesis)

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3′-Methyl-2-oxo-1′,5′-diphenyl-1′,7′-dihydrospiro[indoline-3,4′-pyrazolo[3,4-b]pyridine]-6′-carboxylic Acid

by

,

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and

Molbank 2021, 2021(2), M1214; https://doi.org/10.3390/M1214 - 21 May 2021

Viewed by 1091

Abstract

3′-methyl-2-oxo-1′,5′-diphenyl-1′,7′-dihydrospiro[indoline-3,4′-pyrazolo[3,4-b]pyridine]-6′-carboxylic acid was synthesized using diverse conditions. The best reaction condition consisted of using water as solvent under microwave irradiation, affording product in 76% yield. Full article

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N-[7-Chloro-4-[4-(phenoxymethyl)-1H-1,2,3-triazol-1-yl]quinoline]-acetamide

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,

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and

Molbank 2021, 2021(2), M1213; https://doi.org/10.3390/M1213 - 20 May 2021

Cited by 4 | Viewed by 1662

Abstract

The 1,2,3-triazole is a well-known biologically active pharmacophore constructed by the copper-catalyzed azide–alkyne cycloaddition. We herein reported the synthesis of 4-amino-7-chloro-based [1,2,3]-triazole hybrids via Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition of 4-azido-7-chloroquinoline with an alkyne derivative of acetaminophen. The compound was fully characterized by Fourier-transform [...] Read more.

The 1,2,3-triazole is a well-known biologically active pharmacophore constructed by the copper-catalyzed azide–alkyne cycloaddition. We herein reported the synthesis of 4-amino-7-chloro-based [1,2,3]-triazole hybrids via Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition of 4-azido-7-chloroquinoline with an alkyne derivative of acetaminophen. The compound was fully characterized by Fourier-transform infrared (FTIR), proton nuclear magnetic resonance (¹H-NMR), carbon-13 nuclear magnetic resonance (¹³C-NMR), heteronuclear single quantum coherence (HSQC), ultraviolet (UV) and high-resolution mass spectroscopies (HRMS). This compound was screened in vitro with different normal and cancer cell lines. The drug likeness of the compound was also investigated by predicting its pharmacokinetic properties. Full article

(This article belongs to the Special Issue Synthesis of Flavonoids or Other Nature-Inspired Small Molecules)

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(E)-3-((2-Fluorophenyl)(hydroxy)methylene)imidazo[1,2-a]pyridin-2(3H)-one

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,

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and

Molbank 2021, 2021(2), M1212; https://doi.org/10.3390/M1212 - 14 May 2021

Cited by 1 | Viewed by 1229

Abstract

Treatment of a N-2-pyridyl-β-ketoamide precursor with bromine afforded the first example of the 3-aryl(α-hydroxy)methylenelimidazo[1,2-a]pyridin-2(3H)-one framework. This transformation proceeded through a domino process comprising an initial bromination, cyclization via an intramolecular S_N reaction, and a final keto-enol tautomerism, and [...] Read more.

Treatment of a N-2-pyridyl-β-ketoamide precursor with bromine afforded the first example of the 3-aryl(α-hydroxy)methylenelimidazo[1,2-a]pyridin-2(3H)-one framework. This transformation proceeded through a domino process comprising an initial bromination, cyclization via an intramolecular S_N reaction, and a final keto-enol tautomerism, and allows generation of the fused heterocyclic system and installation of the acyl substituent in a single operation. Full article

(This article belongs to the Special Issue Nitrogen-Containing Molecules: Natural and Synthetic Products Including Coordination Compounds)

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N-(3-Cyano-4,5,6,7-tetrahydrobenzothiophen-2-yl)-2-[[5-[(1,5-dimethyl-3-oxo-2-phenylpyrazol-4-yl)amino]-1,3,4-thiadiazol-2-yl]sulfanyl]acetamide

by

,

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and

Molbank 2021, 2021(2), M1211; https://doi.org/10.3390/M1211 - 10 May 2021

Cited by 3 | Viewed by 1614

Abstract

The small pyrazolone-bearing molecules attract attention and are widely explored in drug design as pharmacological agents. The new pyrazolone-thiadiazole hybrid molecule N-(3-cyano-4,5,6,7-tetrahydrobenzothiophen-2-yl)-2-[[5-[(1,5-dimethyl-3-oxo-2-phenylpyrazol-4-yl)amino]-1,3,4-thiadiazol-2-yl]sulfanyl]acetamide (3) has been synthesized following a two-stage protocol using simple, convenient transformations and cheap, commercially available reagents. The [...] Read more.

The small pyrazolone-bearing molecules attract attention and are widely explored in drug design as pharmacological agents. The new pyrazolone-thiadiazole hybrid molecule N-(3-cyano-4,5,6,7-tetrahydrobenzothiophen-2-yl)-2-[[5-[(1,5-dimethyl-3-oxo-2-phenylpyrazol-4-yl)amino]-1,3,4-thiadiazol-2-yl]sulfanyl]acetamide (3) has been synthesized following a two-stage protocol using simple, convenient transformations and cheap, commercially available reagents. The compound’s structure was confirmed using ¹H, ¹³C nuclear magnetic resonance (NMR), and liquid chromatography–mass spectrometry (LC–MS) spectra. The anti-inflammatory potency of 3 was evaluated in silico using molecular docking. The docking studies results suggest that title compound 3 is of great interest for further structure optimization and in-depth studies as a possible 5-lipoxygenase (5-LOX) inhibitor. Full article

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Palladium-Catalyzed Direct Mono- and Diarylation of Diphenydithienylethenes: A Useful Method for Enhancing Fluorescence Intensity and Aggregation-Induced Emission

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,

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,

,

and

Molbank 2021, 2021(2), M1210; https://doi.org/10.3390/M1210 - 10 May 2021

Viewed by 1458

Abstract

In this study we report efficient method for the syntheses of mono- and diarylated diphenyldithienylethene (DPDTE) via a palladium-catalyzed C–H arylation reaction. These new derivatives showed amplified luminescent properties thanks to a change in polarity, particularly in the presence of an electron-withdrawing groups [...] Read more.

In this study we report efficient method for the syntheses of mono- and diarylated diphenyldithienylethene (DPDTE) via a palladium-catalyzed C–H arylation reaction. These new derivatives showed amplified luminescent properties thanks to a change in polarity, particularly in the presence of an electron-withdrawing groups (EWG). Moreover, the arylated DPDTEs showed dual-emissive phenomena, including fluorescence in organic solvents and aggregation-induced emission. Full article

(This article belongs to the Section Organic Synthesis)

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4-[(4-Chlorophenyl)carbamoyl]butanoic Acid

by

,

,

,

,

and

Molbank 2021, 2021(2), M1209; https://doi.org/10.3390/M1209 - 06 May 2021

Cited by 3 | Viewed by 1388

Abstract

The X-ray crystal structure determination of the glutaric acid-amide derivative, 4-ClC₆H₄N(H)C(=O)(CH₂)₃C(=O)OH (1), is described. The backbone of the molecule adopts an extended, all-trans configuration but the terminal carboxylic acid and phenyl resides are [...] Read more.

The X-ray crystal structure determination of the glutaric acid-amide derivative, 4-ClC₆H₄N(H)C(=O)(CH₂)₃C(=O)OH (1), is described. The backbone of the molecule adopts an extended, all-trans configuration but the terminal carboxylic acid and phenyl resides are twisted out of the plane through the bridging atoms, as seen in the torsion angles of O(carboxylic acid)–C(m)–C(m)–C(m) [13.9(5)°] and C(m)–N–C(p)–C(p) [47.1(4)°]; m = methylene and p = phenyl. The most striking feature of the molecular packing is the formation of supramolecular tapes mediated by carboxylic acid-O–H⋯O(carbonyl) and amide-N–H⋯O(amide) hydrogen bonding. Full article

(This article belongs to the Section Structure Determination)

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