Molbank

6 pages, 1240 KiB

Open AccessCommunication

Synthesis of (5Z)-3-Allyl-5-{[5-(4-methoxyphenyl)thiophen-2-yl]methylidene}-2-sulfanylidene-1,3-thiazolidin-4-one in L-Proline-Based Deep Eutectic Solvent

by Stéphanie Hesse, Isabelle Jourdain, Abderrahim Khatyr and Michael Knorr

Molbank 2024, 2024(4), M1936; https://doi.org/10.3390/M1936 - 10 Dec 2024

Abstract

3-N-allylrhodanine was condensed with 5-(4-methoxyphenyl)-thiophene-2-carbaldehyde in an L-proline-based deep eutectic solvent (DES) to obtain the π-conjugated heterocyclic rhodanine compound (5Z)-3-allyl-5-{[5-(4-methoxyphenyl)thiophen-2-yl]methylidene}-2-sulfanylidene-1,3-thiazolidin-4-one (2). Compound 2 was characterized by NMR spectroscopy, and its UV-vis spectrum was compared with that of [...] Read more.

3-N-allylrhodanine was condensed with 5-(4-methoxyphenyl)-thiophene-2-carbaldehyde in an L-proline-based deep eutectic solvent (DES) to obtain the π-conjugated heterocyclic rhodanine compound (5Z)-3-allyl-5-{[5-(4-methoxyphenyl)thiophen-2-yl]methylidene}-2-sulfanylidene-1,3-thiazolidin-4-one (2). Compound 2 was characterized by NMR spectroscopy, and its UV-vis spectrum was compared with that of the related derivative 3-allyl-5-(4-methoxybenzylidene)-2-sulfanylidene-1,3-thiazolidin-4-one (1). Preliminary results revealed that compound 2 is emissive at room temperature in solution. Full article

(This article belongs to the Section Organic Synthesis and Biosynthesis)

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5 pages, 927 KiB

Open AccessShort Note

5,10-Diiododibenzo[a,e]pentalene

by Natsumi Ohara, Chinatsu Ogiwara and Takuya Kuwabara

Molbank 2024, 2024(4), M1937; https://doi.org/10.3390/M1937 - 10 Dec 2024

Abstract

The crystal structure and the improved synthesis of the title compound (1) are presented. Treatment of 5,10-disilyldibenzo[a,e]pentalenes (2a and 2b) with iodine chloride (ICl) readily provided 1 in good yields. Recrystallization from a dichloromethane/hexane solution [...] Read more.

The crystal structure and the improved synthesis of the title compound (1) are presented. Treatment of 5,10-disilyldibenzo[a,e]pentalenes (2a and 2b) with iodine chloride (ICl) readily provided 1 in good yields. Recrystallization from a dichloromethane/hexane solution afforded single crystals suitable for X-ray diffraction studies. In the packing structure, iodine···iodine interactions classified as type II halogen bonding were found, forming the zigzag I…I chains along the ac-plane. Full article

(This article belongs to the Section Structure Determination)

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6 pages, 809 KiB

Open AccessCommunication

17β-Hydroxy-2-oxa-5α-androstan-3-one

by Savina Stoyanova, Georgi Dinkov and Milen G. Bogdanov

Molbank 2024, 2024(4), M1935; https://doi.org/10.3390/M1935 - 9 Dec 2024

Abstract

We have successfully synthesized a 2-oxa androstane derivative, 17β-hydroxy-2-oxa-5α-androstan-3-one (6), and confirmed its structure using NMR spectroscopy and mass spectrometry. Full article

(This article belongs to the Section Organic Synthesis and Biosynthesis)

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12 pages, 3610 KiB

Open AccessCommunication

Synthesis and Characterization of Hydrazine Bridge Cyclotriphosphazene Derivatives with Amide–Schiff Base Linkages Attached to Decyl and Hydroxy Terminal Groups

by Fatin Junaidah Mohamad Fazli and Zuhair Jamain

Molbank 2024, 2024(4), M1934; https://doi.org/10.3390/M1934 - 7 Dec 2024

Abstract

New cyclotriphosphazene derivatives featuring amide–Schiff base linkages with a hydrazine bridge and different terminal ends, such as decyl alkyl chains and hydroxy groups, were successfully synthesized and characterized. Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), and CHN elemental analysis were used [...] Read more.

New cyclotriphosphazene derivatives featuring amide–Schiff base linkages with a hydrazine bridge and different terminal ends, such as decyl alkyl chains and hydroxy groups, were successfully synthesized and characterized. Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), and CHN elemental analysis were used to characterize the structures of these compounds. The formation of hydrazine-bridged cyclotriphosphazene derivatives with amide–Schiff base linkages was confirmed by the FTIR spectra, showing a primary amine band for the amide linkage around ~3300 cm⁻¹ and a band for the Schiff base linkage near ~1595 cm⁻¹. This was further supported by NMR analysis, which displayed an amide proton (H-N-C=O) at ~δ 10.00 ppm and an azomethine proton (H-C=N) within the δ 8.40–8.70 ppm range. The ³¹P NMR spectra of cyclotriphosphazene compounds display a singlet at ~δ 8.20 ppm, indicating an upfield shift that suggests the complete substitution of all phosphorus atoms with identical side chains. Furthermore, CHN analysis verified the purity of the synthesized compounds, with a percentage error below 2%. The introduction of hydrazine bridges and amide–Schiff base linkages into the cyclotriphosphazene core significantly enriches the molecular structure with diverse functional groups. These modifications not only improve the compound’s stability and reactivity, but also expand its potential for a wide range of applications. Full article

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6 pages, 851 KiB

Open AccessCommunication

Cyclization Modes in Anilides of N-Protected 3-Oxo-4-phenylaminobutyric Acid Under Knorr Conditions

by Plamen Angelov and Yordanka Mollova-Sapundzhieva

Molbank 2024, 2024(4), M1933; https://doi.org/10.3390/M1933 - 6 Dec 2024

Abstract

Anilides of 3-oxo-4-phenylaminobutyric acid with Troc or COOEt protection at the phenylamino group undergo competing cyclization processes in neat polyphosphoric acid at 80 °C. Depending on the protecting group and the duration of the process, three main products in different ratios are formed. [...] Read more.

Anilides of 3-oxo-4-phenylaminobutyric acid with Troc or COOEt protection at the phenylamino group undergo competing cyclization processes in neat polyphosphoric acid at 80 °C. Depending on the protecting group and the duration of the process, three main products in different ratios are formed. Along with the quinolin-2-ones, resulting from the classic Knorr cyclization, an indole derivative and a spirocyclic product have also been obtained from the COOEt-protected substrate. It has been demonstrated that the obtained indole derivative is capable of further dearomative spirocyclization under the studied conditions. Full article

(This article belongs to the Section Organic Synthesis and Biosynthesis)

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Scheme 1

7 pages, 1507 KiB

Open AccessShort Note

1,1-Bis(4-hydroxyphenyl)-2-ferrocenylbutane

by Jérémy Forté, Patrick Herson and Pascal Pigeon

Molbank 2024, 2024(4), M1932; https://doi.org/10.3390/M1932 - 6 Dec 2024

Abstract

Ferrociphenols are anticancer organometallic molecules bearing a ferrocene group linked, at least, to one para-phenol moiety via a double bond. Up to the present, their biological activity has been thought to be linked to their oxidation within cells to form a reactive [...] Read more.

Ferrociphenols are anticancer organometallic molecules bearing a ferrocene group linked, at least, to one para-phenol moiety via a double bond. Up to the present, their biological activity has been thought to be linked to their oxidation within cells to form a reactive quinone-methide metabolite with the participation of this central double bond. To prove this assertion, the alkenyl entity of ferrociphenol 1a (1,1-bis-(4-hydroxyphenyl)-2-ferrocenylbut-1-ene) was reduced by triethylsilane in an acidic medium to obtain the alkyl counterpart 1,1-bis(4-hydrophenyl)-2-ferrocenylbutane. 1,1-bis(4-hydrophenyl)-2-ferrocenylbutane was fully characterized by ¹H NMR (including COSY), ¹³C NMR, HRMS, IR, elemental analysis and X-ray diffraction (XRD). Although missing the central double bond, this compound remains biologically active, opening the way to a new family of anticancer ferrocene-containing molecules. Full article

(This article belongs to the Section Structure Determination)

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4 pages, 1292 KiB

Open AccessShort Note

4-(Benzoxazol-2-yl)phenyl 3-((3-Chloro-1,4-Naphthoquinon-2-yl)amino)phenyl Sulfate

by Nadezhda V. Danilenko, Mariia O. Lutsuk and Andrei I. Khlebnikov

Molbank 2024, 2024(4), M1930; https://doi.org/10.3390/M1930 - 5 Dec 2024

Abstract

New 4-(benzoxazol-2-yl)phenyl 3-((3-chloro-1,4-naphthoquinon-2-yl)amino)phenyl sulfate was synthesized via the SuFEx click reaction between fluorosulfate-containing 1,4-naphthoquinone and 2-(4-hydroxyphenyl)benzoxazole. 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) was used as an organic base, while triethylamine was inactive in this reaction. Full article

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5 pages, 788 KiB

Open AccessCommunication

Fluorination Homologation of Biorenewable Synthon Cyrene

by Johannes Puschnig and Ben W. Greatrex

Molbank 2024, 2024(4), M1929; https://doi.org/10.3390/M1929 - 5 Dec 2024

Abstract

A one-carbon difluorocyclopropanation/ring-expansion has been developed for the chiral synthon Cyrene, which is obtained via cellulose pyrolysis. The ring-enlargement was achieved by converting Cyrene (dihydrolevoglucosenone) into an enamine, reacting it with an in situ-generated difluorocarbene, and then heating it to ring-open the cyclopropane. [...] Read more.

A one-carbon difluorocyclopropanation/ring-expansion has been developed for the chiral synthon Cyrene, which is obtained via cellulose pyrolysis. The ring-enlargement was achieved by converting Cyrene (dihydrolevoglucosenone) into an enamine, reacting it with an in situ-generated difluorocarbene, and then heating it to ring-open the cyclopropane. Access to the product provides access to fluorinated analogues of this valuable chiral biomass derivative. Full article

(This article belongs to the Section Organic Synthesis and Biosynthesis)

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Graphical abstract

4 pages, 903 KiB

Open AccessShort Note

2-((3R,9bS)-5,5-Dioxido-2,3-dihydro-9bH-benzo[4,5]isothiazolo[3,2-b]oxazol-3-yl)-1-phenylethan-1-one

by Yeongju Kim and Sung-Gon Kim

Molbank 2024, 2024(4), M1931; https://doi.org/10.3390/M1931 - 5 Dec 2024

Abstract

A highly efficient method has been developed for preparing 2-((3R,9bS)-5,5-dioxido-2,3-dihydro-9bH-benzo[4,5]isothiazolo[3,2-b]oxazol-3-yl)-1-phenylethan-1-one. This enantioenriched title compound was obtained via an organocatalytic asymmetric [3+2]-cycloaddition of benzo[d]isothiazole 1,1-dioxide with (E)-4-hydroxy-1-phenylbut-2-en-1-one, using a bifunctional squaramide-based chiral [...] Read more.

A highly efficient method has been developed for preparing 2-((3R,9bS)-5,5-dioxido-2,3-dihydro-9bH-benzo[4,5]isothiazolo[3,2-b]oxazol-3-yl)-1-phenylethan-1-one. This enantioenriched title compound was obtained via an organocatalytic asymmetric [3+2]-cycloaddition of benzo[d]isothiazole 1,1-dioxide with (E)-4-hydroxy-1-phenylbut-2-en-1-one, using a bifunctional squaramide-based chiral catalyst. The reaction yielded 99% of the product with high enantioselectivity and diastereoselectivity (89:11 er and >20:1 dr). The structure of the newly synthesized compound was confirmed by ¹H-, ¹³C-NMR, IR and mass spectral data. Full article

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14 pages, 13840 KiB

Open AccessCommunication

Crystal Structures of 9,9-Disubstituted Fluorene Derivatives Bearing Methyl, Hydroxymethyl or Pyridinylmethyl Groups

by Thomas Hanauer, Pierre Seidel, Wilhelm Seichter and Monika Mazik

Molbank 2024, 2024(4), M1928; https://doi.org/10.3390/M1928 - 3 Dec 2024

Abstract

The wide range of application possibilities of fluorene derivatives, due to their unique physical and chemical properties, has made this class of molecules important for various disciplines. The synthesis of these compounds and the study of their properties are, therefore, of great scientific [...] Read more.

The wide range of application possibilities of fluorene derivatives, due to their unique physical and chemical properties, has made this class of molecules important for various disciplines. The synthesis of these compounds and the study of their properties are, therefore, of great scientific interest. Due to their reactivity and sensitivity to oxidation, the 9-position of the fluorene skeleton is often double substituted, for example, to ensure the long-term stability of materials. Single crystal structure analysis, among other methods, plays a very important role in the development of various fluorene-based systems. In this paper, the crystal structures of three 9,9-disubstituted fluorene derivatives bearing methyl, hydroxymethyl or pyridinylmethyl groups are described (three solvent-free structures and one toluene solvate). A detailed evaluation of the intermolecular interactions, supported by Hirshfeld surface analysis, is the subject of this article. Full article

(This article belongs to the Section Structure Determination)

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Graphical abstract

6 pages, 1298 KiB

Open AccessShort Note

2-([1,1′-Biphenyl]-4-yl)-5-[(E)-2-(3-methoxy-1-phenyl-1H-pyrazol-4-yl)ethenyl]-3,3-dimethyl-3H-indole

by Gabrielė Varvuolytė, Aurimas Bieliauskas, Neringa Kleizienė, Asta Žukauskaitė and Algirdas Šačkus

Molbank 2024, 2024(4), M1927; https://doi.org/10.3390/M1927 - 28 Nov 2024

Abstract

The ligandless palladium-catalyzed Heck reaction of 4-ethenyl-3-methoxy-1-phenyl-1H-pyrazole and 2-([1,1′-biphenyl]-4-yl)-5-bromo-3,3-dimethyl-3H-indole gave the previously unreported 2-([1,1′-biphenyl]-4-yl)-5-[(E)-2-(3-methoxy-1-phenyl-1H-pyrazol-4-yl)ethenyl]-3,3-dimethyl-3H-indole in 45% yield. The compound was characterized using NMR, FT-IR spectroscopy, and HRMS data. The optical properties of the [...] Read more.

The ligandless palladium-catalyzed Heck reaction of 4-ethenyl-3-methoxy-1-phenyl-1H-pyrazole and 2-([1,1′-biphenyl]-4-yl)-5-bromo-3,3-dimethyl-3H-indole gave the previously unreported 2-([1,1′-biphenyl]-4-yl)-5-[(E)-2-(3-methoxy-1-phenyl-1H-pyrazol-4-yl)ethenyl]-3,3-dimethyl-3H-indole in 45% yield. The compound was characterized using NMR, FT-IR spectroscopy, and HRMS data. The optical properties of the compound were investigated in tetrahydrofuran by UV-Vis and fluorescence spectroscopy. Full article

(This article belongs to the Section Organic Synthesis and Biosynthesis)

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10 pages, 3408 KiB

Open AccessCommunication

Synthesis of N-p-Fluorothiosemicarbazone and of Bis(N-p-Fluorophenylthiourea): Crystal Structure and Conformational Analysis of N,N′-Bis(4-Fluorophenyl)Hydrazine-1,2-Bis(Carbothioamide)

by Sirine Salhi, Dorra Kanzari-Mnallah, Isabelle Jourdain, Michael Knorr, Carsten Strohmann, Jan-Lukas Kirchhoff, Hédi Mrabet and Azaiez Ben Akacha

Molbank 2024, 2024(4), M1926; https://doi.org/10.3390/M1926 - 28 Nov 2024

Abstract

The reaction of the phosphonated hydrazone (2-hydrazineylidenepropyl) diphenylphosphine oxide 1 with p-fluorophenyl-isothiocyanate yields as a major product the thiosemicarbazone Ph₂P(=O)CH₂{C=N-NH(C=S)-N(H)C₆H₄F}CH₃ (2-(1-(diphenylphosphoryl)propan-2-ylidene)-N-(4-fluorophenyl)hydrazine-1-carbothioamide) 2 along with bis(N-p-fluorophenylthiourea) 3 as [...] Read more.

The reaction of the phosphonated hydrazone (2-hydrazineylidenepropyl) diphenylphosphine oxide 1 with p-fluorophenyl-isothiocyanate yields as a major product the thiosemicarbazone Ph₂P(=O)CH₂{C=N-NH(C=S)-N(H)C₆H₄F}CH₃ (2-(1-(diphenylphosphoryl)propan-2-ylidene)-N-(4-fluorophenyl)hydrazine-1-carbothioamide) 2 along with bis(N-p-fluorophenylthiourea) 3 as a minor product. The latter compound 3 was isolated as the main product by direct treatment of p-FC₆H₄N=C=S with hydrazine in a 2:1 ratio. Both 2 and 3 were characterized by NMR. Furthermore, the molecular structure of 3 was elucidated by an X-ray diffraction study, revealing both intra- and intermolecular secondary interactions. A conformational DFT study, at the B3LYP/6-311 G++ (d, p) level of theory, confirms a good match between the calculated structure and the experimental one. Full article

(This article belongs to the Section Organic Synthesis and Biosynthesis)

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5 pages, 913 KiB

Open AccessCommunication

3-Methyl-2-(5-((trimethylsilyl)ethynyl)pyridin-2-yl)butan-2-ol

by Oleg A. Mikhailov, Almira R. Kurbangalieva and Ilya D. Gridnev

Molbank 2024, 2024(4), M1925; https://doi.org/10.3390/M1925 - 27 Nov 2024

Abstract

The reactions of dialkylzinc reagents with ketones are scarcely studied. In this paper, we describe a previously unknown direct alkylation of substituted 2-acetylpyridine with diisopropyl zinc, which gave a corresponding novel alcohol with 82% yield. Full article

(This article belongs to the Section Organic Synthesis and Biosynthesis)

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Scheme 1

7 pages, 1667 KiB

Open AccessShort Note

Ammonium Oxathioamidate

by M. Carla Aragoni, David B. Cordes, Anna Pintus, Enrico Podda, Riccardo Serra, Alexandra M. Z. Slawin, J. Derek Woollins and Massimiliano Arca

Molbank 2024, 2024(4), M1924; https://doi.org/10.3390/M1924 - 26 Nov 2024

Abstract

Ammonium oxathioamidate (1) was synthesised by the reaction between O-ethyl-thioxamate (oxalic acid-1-amide-2-O-ethyl ester) and ammonium hydrogen carbonate in water solution. Compound 1 was fully characterised by both microanalytical (elemental analysis, melting point determination) and spectroscopic means (FT-IR and [...] Read more.

Ammonium oxathioamidate (1) was synthesised by the reaction between O-ethyl-thioxamate (oxalic acid-1-amide-2-O-ethyl ester) and ammonium hydrogen carbonate in water solution. Compound 1 was fully characterised by both microanalytical (elemental analysis, melting point determination) and spectroscopic means (FT-IR and NMR spectroscopy). Crystals suitable for single-crystal X-ray diffraction were isolated by slow evaporation of an ethanol solution of the compound. The analysis of the crystal packing reveals the prominent role exerted by intermolecular hydrogen bonding (HB) and chalcogen bonding (ChB) interactions. Full article

(This article belongs to the Section Structure Determination)

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8 pages, 2827 KiB

Open AccessCommunication

Coordination of O-Propyl-N-phenylthiocarbamate to HgI₂ and the Crystallographic Characterization of an Anilinium Chloride Thiocarbamate Adduct

by Wafa Arar, Nuri Ekici, Michael Knorr, Isabelle Jourdain, Carsten Strohmann and Jan-Lukas Kirchhoff

Molbank 2024, 2024(4), M1923; https://doi.org/10.3390/M1923 - 22 Nov 2024

Abstract

In order to investigate the coordination chemistry of O-alkyl N-aryl thiocarbamate ligands, HgI₂ was reacted with one equivalent of PrOC(=S)N(H)Ph L in toluene solution to afford the 1D polymeric title compound [{IHg(μ-I)}{κ¹-PrOC(=S)N(H)Ph}]_n CP1. The formation [...] Read more.

In order to investigate the coordination chemistry of O-alkyl N-aryl thiocarbamate ligands, HgI₂ was reacted with one equivalent of PrOC(=S)N(H)Ph L in toluene solution to afford the 1D polymeric title compound [{IHg(μ-I)}{κ¹-PrOC(=S)N(H)Ph}]_n CP1. The formation of this iodide-bridged coordination polymer was ascertained by a single-crystal X-ray diffraction study performed at 100 K, as well as the formation of an adduct between anilinium chloride and L forming a supramolecular ribbon of composition [L(PhNH₃)(Cl)]. The occurrence of anilinium chloride is due to the partial hydrolysis of L in the presence of HCl. Full article

(This article belongs to the Section Organic Synthesis and Biosynthesis)

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8 pages, 2407 KiB

Open AccessShort Note

6,8-Dibromo-11H-indeno[1,2-b]quinolin-11-one

by Anastasia R. Kovrizhina, Dauren Tolegen, Dmitry I. Pavlov, Andrei S. Potapov and Andrei I. Khlebnikov

Molbank 2024, 2024(4), M1922; https://doi.org/10.3390/M1922 - 21 Nov 2024

Abstract

We report the synthesis of the new compound 6,8-dibromo-11H-indeno[1,2-b]quinolin-11-one, which presents an important type of nitrogen-containing heterocycles and is a useful intermediate product in organic synthesis. The structure of the compound was confirmed by the single crystal X-ray diffraction. [...] Read more.

We report the synthesis of the new compound 6,8-dibromo-11H-indeno[1,2-b]quinolin-11-one, which presents an important type of nitrogen-containing heterocycles and is a useful intermediate product in organic synthesis. The structure of the compound was confirmed by the single crystal X-ray diffraction. Molecular docking analysis revealed that 6,8-dibromo-11H-indeno[1,2-b]quinolin-11-one may effectively intercalate with DNA. The synthesized indenoquinoline derivative thus represents a promising lead compound for developing targeted anticancer and anti-inflammatory drugs. Full article

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5 pages, 824 KiB

Open AccessShort Note

Cyclo[Tri(thiomethyl-1,2-phenylmethylene)]

by Pablo Simón Marqués, Nicolas Bréfuel and Claire Kammerer

Molbank 2024, 2024(4), M1921; https://doi.org/10.3390/M1921 - 21 Nov 2024

Abstract

During the purification of a reported compound named 1,3-dihydrobenzo[c]thiophene, we isolated an unexpected molecule in one of the chromatography fractions by serendipity. Structural elucidation using common techniques such as 1D and 2D NMR, and mass spectrometry revealed the nature of this [...] Read more.

During the purification of a reported compound named 1,3-dihydrobenzo[c]thiophene, we isolated an unexpected molecule in one of the chromatography fractions by serendipity. Structural elucidation using common techniques such as 1D and 2D NMR, and mass spectrometry revealed the nature of this novel product characterized as cyclo[tri(thiomethyl-1,2-phenylmethylene)]. Full article

(This article belongs to the Section Organic Synthesis and Biosynthesis)

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4 pages, 611 KiB

Open AccessShort Note

trans-11-(3,4-Dimethoxyphenyl)-2,3,8,9-tetramethoxy-6-oxo-11,12-dihydro-6H-dibenzo[c,h]chromene-12-carboxylic Acid

by Victor Angelov, Savina Stoyanova and Milen G. Bogdanov

Molbank 2024, 2024(4), M1920; https://doi.org/10.3390/M1920 - 19 Nov 2024

Abstract

The title compound, trans-11-(3,4-Dimethoxyphenyl)-2,3,8,9-tetramethoxy-6-oxo-11,12-dihydro-6H-dibenzo[c,h]chromene-12-carboxylic acid (4), was synthesized for the first time via a two-step protocol from 3,4-dimethoxyhomophthalic anhydride (1) and 3,4-dimethoxybenzaldehyde (DMBA). In the first step, 1 reacts with DMBA to give [...] Read more.

The title compound, trans-11-(3,4-Dimethoxyphenyl)-2,3,8,9-tetramethoxy-6-oxo-11,12-dihydro-6H-dibenzo[c,h]chromene-12-carboxylic acid (4), was synthesized for the first time via a two-step protocol from 3,4-dimethoxyhomophthalic anhydride (1) and 3,4-dimethoxybenzaldehyde (DMBA). In the first step, 1 reacts with DMBA to give trans-3-(3,4-dimethoxyphenyl)-6,7-dimethoxy-1-oxo-3,4-dihydro-1H-2-benzopyran-4-carboxylic acid (2), which further reacts with two additional equivalents of 1 to give 4. Compound 4 was characterized by means of spectral methods—¹H-, ¹³C-, DEPT-135-NMR, and HRMS. Full article

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Scheme 1

8 pages, 651 KiB

Open AccessCommunication

A Gram Scale Synthesis of 3,4-Dihalogen Substituted 1,8-Naphthalimides

by Denitsa Anastasova, Monika Mutovska, Natali Simeonova, Irena Zagranyarska, Zlatina Vlahova, Stanimir Stoyanov and Yulian Zagranyarski

Molbank 2024, 2024(4), M1918; https://doi.org/10.3390/M1918 - 18 Nov 2024

Abstract

A general protocol for the synthesis of 3,4-dihalogen substituted 1,8-naphthalimides is proposed, starting from available and cheap 1,8-naphthalic anhydride. The reported new compounds have only bromine or chlorine atoms as substituents, in contrast to the known iodo-containing analogues. This is an advantage in [...] Read more.

A general protocol for the synthesis of 3,4-dihalogen substituted 1,8-naphthalimides is proposed, starting from available and cheap 1,8-naphthalic anhydride. The reported new compounds have only bromine or chlorine atoms as substituents, in contrast to the known iodo-containing analogues. This is an advantage in possible aryl nucleophilic substitution or cross-coupling modifications, making them interesting and important building-block molecules in naphthalimide chemistry. Although the procedure includes five synthetic steps, they are quick and straightforward. The overall yields are relatively high (48–62%), and only one column of chromatographic purification is needed. All the reactions were carried out on a multigram scale to allow the target building-block compounds to be obtained in sufficient amounts for further derivatizations. Full article

(This article belongs to the Section Organic Synthesis and Biosynthesis)

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