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Molbank, Volume 2021, Issue 3 (September 2021) – 42 articles

Cover Story (view full-size image): Benzoxazole-based compounds have a wide range of biological activities, and their fluorosulfate derivatives have the ability to react with various functional groups, making it possible to obtain novel compounds. We synthesized the new 2-(2-(fluorosulfonyloxy)phenyl)benzoxazole (2) by the SuFEx click reaction between the corresponding phenol and gaseous SO2F2 in a two-chamber reactor. The influence of SO2F2 pressure on the reaction selectivity was investigated. Compound 2 is the first example of benzoxazole which bears a fluorosulfonyloxy-containing substituent at position 2 of the heterocycle. The anti-cancer potency of 2 was evaluated in silico using molecular docking. It was shown that compound 2 is of great interest for further studies as a possible anaplastic lymphoma kinase inhibitor. View this paper
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Communication
Hybrid Pyridine Bis-Anthracene-Imidazolium Salt: NMR Studies on Zn-Acetate Complexation
Molbank 2021, 2021(3), M1280; https://doi.org/10.3390/M1280 - 14 Sep 2021
Viewed by 1184
Abstract
We report here the design and synthesis of a new hybrid bis-anthracene-imidazolium salt, having a pyridine scaffold. NMR studies of dimer generation, as well as complexation with zinc acetate were performed. Full article
(This article belongs to the Section Organic Synthesis)
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2-Oxo-2H-chromen-7-yl 4-chlorobenzoate
Molbank 2021, 2021(3), M1279; https://doi.org/10.3390/M1279 - 14 Sep 2021
Cited by 5 | Viewed by 1784
Abstract
We describe the synthesis of 2-oxo-2H-chromen-7-yl 4-chlorobenzoate 3 in 88% yield by the O-acylation reaction of 7-hydroxy-2H-chromen-2-one 1 with 4-chlorobenzoyl chloride 2 in dichloromethane using a slight excess of triethylamine at 20 °C for 1 h. The ester [...] Read more.
We describe the synthesis of 2-oxo-2H-chromen-7-yl 4-chlorobenzoate 3 in 88% yield by the O-acylation reaction of 7-hydroxy-2H-chromen-2-one 1 with 4-chlorobenzoyl chloride 2 in dichloromethane using a slight excess of triethylamine at 20 °C for 1 h. The ester 3 was completely characterized by mass spectrometry, IR, UV–Vis, 1D, and 2D NMR spectroscopy. Full article
(This article belongs to the Special Issue Synthesis of Flavonoids or Other Nature-Inspired Small Molecules)
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4,6-Bis((E)-2-(4′-N,N-diphenylamino-[1,1′-biphenyl]-4-yl)vinyl)-2-phenylpyrimidine
Molbank 2021, 2021(3), M1278; https://doi.org/10.3390/M1278 - 10 Sep 2021
Cited by 1 | Viewed by 1068
Abstract
In this contribution, we designed a 4,6-distyrylpyrimidine chromophore with diphenylamino electron-donating groups and biphenylenevinylene extended π-conjugated linkers. This compound has been synthesized in two steps from 4,6-dimethyl-2-phenylpyrimidine by a double Knoevenagel reaction with 4-bromobenzaldehyde followed by a double Suzuki–Miyaura cross coupling reaction with [...] Read more.
In this contribution, we designed a 4,6-distyrylpyrimidine chromophore with diphenylamino electron-donating groups and biphenylenevinylene extended π-conjugated linkers. This compound has been synthesized in two steps from 4,6-dimethyl-2-phenylpyrimidine by a double Knoevenagel reaction with 4-bromobenzaldehyde followed by a double Suzuki–Miyaura cross coupling reaction with 4-(N,N-diphenylamino)phenylboronic acid. This compound exhibits intense emission in moderately polar solvents as well as in solid state. This compound is characterized by an intense emission solvatochromism with emission ranging from blue in non polar n-heptane to orange in dichloromethane. This chromophore is also sensible to the presence of acid with a bathochromic shift of the charge transfer absorption band and emission quenching. Full article
(This article belongs to the Section Organic Synthesis)
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2,6-Dimethoxybenzyl Bromide
Molbank 2021, 2021(3), M1277; https://doi.org/10.3390/M1277 - 07 Sep 2021
Viewed by 1281
Abstract
The unstable title compound has been characterized for the first time. Its melting point, UV, IR, 1H and 13C-NMR and high-resolution mass spectra are presented. The X-ray structure has also been determined and shows a rather long C–Br bond perpendicular to [...] Read more.
The unstable title compound has been characterized for the first time. Its melting point, UV, IR, 1H and 13C-NMR and high-resolution mass spectra are presented. The X-ray structure has also been determined and shows a rather long C–Br bond perpendicular to the otherwise planar molecule. Full article
(This article belongs to the Section Organic Synthesis)
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Article
2-Chloro-4,6-bis{(E)-3-methoxy-4-[(4-methoxybenzyl)oxy]styryl}pyrimidine: Synthesis, Spectroscopic and Computational Evaluation
Molbank 2021, 2021(3), M1276; https://doi.org/10.3390/M1276 - 07 Sep 2021
Cited by 1 | Viewed by 1546
Abstract
A novel curcumin analog namely 2-chloro-4,6-bis{(E)-3-methoxy-4-[(4-methoxybenzyl)oxy]-styryl}pyrimidine (compound 7) was synthesized by three-step reaction. The condensation reaction of protected vanillin with 2-chloro-4,6-dimethylpyrimidine (6) was the most efficient step, resulting in a total yield of 72%. The characterization [...] Read more.
A novel curcumin analog namely 2-chloro-4,6-bis{(E)-3-methoxy-4-[(4-methoxybenzyl)oxy]-styryl}pyrimidine (compound 7) was synthesized by three-step reaction. The condensation reaction of protected vanillin with 2-chloro-4,6-dimethylpyrimidine (6) was the most efficient step, resulting in a total yield of 72%. The characterization of compound 7 was performed by 1H and 13C nuclear magnetic resonance (NMR), as well as high-resolution mass spectrometry. The experimental spectrometric data were compared with the theoretical spectra obtained by the density functional theory (DFT) method, showing a perfect match between them. UV-visible spectroscopy and steady-state fluorescence emission studies were performed for compound 7 in solvents of different polarities and the results were correlated with DFT calculations. Compound 7 showed a solvatochromism effect presenting higher molar extinction coefficient (log ε = 4.57) and fluorescence quantum yield (ϕ = 0.38) in toluene than in acetonitrile or methanol. The simulation of both frontier molecular orbitals (FMOs) and molecular electrostatic potential (MEP) suggested that the experimental spectra profile in toluene was not interfered by a possible charge transfer. These results are an indication of a low probability of compound 7 in reacting with unsaturated phospholipids in future applications as a fluorescent dye in biological systems. Full article
(This article belongs to the Special Issue Synthesis of Flavonoids or Other Nature-Inspired Small Molecules)
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Communication
Practical and Asymmetric Synthesis of Apremilast Using Ellman’s Sulfinamide as a Chiral Auxiliary
Molbank 2021, 2021(3), M1275; https://doi.org/10.3390/M1275 - 02 Sep 2021
Viewed by 2104
Abstract
Herein, we described a new protocol for the asymmetric synthesis of apremilast using tert-butanesulfinamide as a chiral auxiliary. This synthetic route consisted of four steps starting from the commercially available 3-hydroxy-4-methoxybenzaldehyde, and apremilast was accordingly obtained in an overall 56% yield and [...] Read more.
Herein, we described a new protocol for the asymmetric synthesis of apremilast using tert-butanesulfinamide as a chiral auxiliary. This synthetic route consisted of four steps starting from the commercially available 3-hydroxy-4-methoxybenzaldehyde, and apremilast was accordingly obtained in an overall 56% yield and with 95.5% ee. Full article
(This article belongs to the Section Organic Synthesis)
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Communication
4-(((4-Methoxyphenyl)amino)methyl)-N,N-dimethylaniline and 2-Methoxy-5-((phenylamino)methyl)phenol
Molbank 2021, 2021(3), M1274; https://doi.org/10.3390/M1274 - 31 Aug 2021
Viewed by 1307
Abstract
Molecular structures of 4-(((4-methoxyphenyl)amino)methyl)-N,N-dimethylaniline and 2-methoxy-5-((phenylamino)methyl)phenol synthesized via Schiff bases reduction route are reported. The compounds consist of asymmetric units of C16H20N2O (1) and C14H15NO2 ( [...] Read more.
Molecular structures of 4-(((4-methoxyphenyl)amino)methyl)-N,N-dimethylaniline and 2-methoxy-5-((phenylamino)methyl)phenol synthesized via Schiff bases reduction route are reported. The compounds consist of asymmetric units of C16H20N2O (1) and C14H15NO2 (2) in orthorhombic and monoclinic crystal systems, respectively. Compound 1 consist of intermolecular C11—H11···N2 hydrogen bonding with C11···N21 = 3.463(4) Å. The hydroxyl group in 2 is also involved in intermolecular O2—H2···O2 and O2—H2···O21 hydrogen bonding with O2···O11 = 2.8885(15) Å and O1···O21 = 2.9277(5) Å. The molecular structures of the compounds are stabilized by secondary intermolecular interactions of C1—H1B···O11 and C5—H···(C41, C51, C61, C71) for 1 and H···C, C—H···O and N—H···C for 2. The reported compounds are important starting material for the synthesis of many compounds such as azo dyes and dithiocarbamate. Full article
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Communication
Synthesis of 4-[(1H-Benzimidazol-2-yl)sulfanyl]benzaldehyde and 2-({4-[(1H-Benzimidazol-2-yl)sulfanyl]phenyl}methylidene)hydrazine-1-carbothioamide
Molbank 2021, 2021(3), M1273; https://doi.org/10.3390/M1273 - 26 Aug 2021
Cited by 1 | Viewed by 1723
Abstract
Here we describe the preparation of 2-(4-((1H-benzo[d]imidazol-2-yl)thio)-benzylidene)-hydrazine-1-carbothioamide in two steps. In the first step, 1,3-dihydro-2H-1,3-benzimidazole-2-thione was reacted with 4-fluorobenzaldehyde in DMSO to get 4-[(1H-benzimidazol-2-yl)sulfanyl]benzaldehyde in high yield. The reaction of the obtained aldehyde with thiosemicarbazide in ethanol at reflux [...] Read more.
Here we describe the preparation of 2-(4-((1H-benzo[d]imidazol-2-yl)thio)-benzylidene)-hydrazine-1-carbothioamide in two steps. In the first step, 1,3-dihydro-2H-1,3-benzimidazole-2-thione was reacted with 4-fluorobenzaldehyde in DMSO to get 4-[(1H-benzimidazol-2-yl)sulfanyl]benzaldehyde in high yield. The reaction of the obtained aldehyde with thiosemicarbazide in ethanol at reflux temperature yielded 2-({4-[(1H-benzimidazol-2-yl)sulfanyl]phenyl}methylidene)hydrazine-1-carbothioamide. The structure of the synthesized compounds was established by NMR spectroscopy (1H, 13C), mass spectrometry, and infrared spectroscopy. Full article
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3-(3-Hydroxypropyl)-2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxaldehyde Methyl Hemiacetal
Molbank 2021, 2021(3), M1272; https://doi.org/10.3390/M1272 - 20 Aug 2021
Viewed by 1098
Abstract
The synthesis of 3-(3-hydroxypropyl)-2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxaldehyde as a stable methyl hemiacetal through a convenient 3-step procedure is reported. The molecule is multifunctional as it contains a formyl group, a hydroxyl group and the imide moiety. Each of these groups can play a role in specific [...] Read more.
The synthesis of 3-(3-hydroxypropyl)-2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxaldehyde as a stable methyl hemiacetal through a convenient 3-step procedure is reported. The molecule is multifunctional as it contains a formyl group, a hydroxyl group and the imide moiety. Each of these groups can play a role in specific transformations or uses. Full article
(This article belongs to the Section Organic Synthesis)
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5-(2,6-Diacetamidopyridin-4-yl)-kryptoBODIPY
Molbank 2021, 2021(3), M1271; https://doi.org/10.3390/M1271 - 13 Aug 2021
Viewed by 1241
Abstract
The development of new dyes for various fields of application is of primary interest for the scientific community, among these BODIPY are widely studied for their versatility. This communication describes the synthesis of a BODIPY dye on which a diacetoamidopyridine moiety is connected [...] Read more.
The development of new dyes for various fields of application is of primary interest for the scientific community, among these BODIPY are widely studied for their versatility. This communication describes the synthesis of a BODIPY dye on which a diacetoamidopyridine moiety is connected in meso position. The synthesis procedure requires a one-pot step and the dye is obtained with a yield of 20%. The diacetoamido portion contains chemical functionalities able to favor the interaction of BODIPY with complementary molecules, such as uracil or thymine, offering potential applications for the design of new functional materials or sensors. Full article
(This article belongs to the Section Organic Synthesis)
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2-((E)-2-((E)-4-Chloro-5-(2-((E)-5-methoxy-3,3-dimethyl-1-(3-phenylpropyl)indolin-2-ylidene) ethylidene)-1,1-dimethyl-1,2,5,6-tetrahydropyridin-1-ium-3-yl)vinyl)-5-methoxy-3,3-dimethyl-1-(3-phenylpropyl)-3H-indol-1-ium
Molbank 2021, 2021(3), M1270; https://doi.org/10.3390/M1270 - 11 Aug 2021
Cited by 2 | Viewed by 1532
Abstract
A heptamethine fluorophore, ERB-60, has been synthesized efficiently in four steps in a good yield. The structure of this fluorophore consists of an electron-donating group (methoxy), a hydrophobic moiety (phenylpropyl) with a rotatable bond, a quaternary ammonium fragment, and indolium rings at [...] Read more.
A heptamethine fluorophore, ERB-60, has been synthesized efficiently in four steps in a good yield. The structure of this fluorophore consists of an electron-donating group (methoxy), a hydrophobic moiety (phenylpropyl) with a rotatable bond, a quaternary ammonium fragment, and indolium rings at the terminal ends connected via polymethine chain. All these inherent chemical features fine-tuned the optical properties of the fluorophore. This compound was characterized by both 1H NMR, 13C NMR and mass spectra. The optical properties, including molar absorptivity, fluorescence, Stokes’s shift, and quantum yield, were measured in different solvents such as DMSO, DMF, MeCN, i-PrOH, MeOH, and H2O. The wavelengths of maximum absorbance of ERB-60 were found to be in the range of 745–770 nm based on the solvents used. In decreasing order, the maximum wavelength of absorbance of ERB-60 in the tested solvents was DMSO > DMF > i-PrOH > MeOH > MeCN > H2O while the decreasing order of the extinction coefficient was found to be MeCN > MeOH > DMSO > i-PrOH > H2O > DMF. ERB-60 was found to be more photostable than IR-786 iodide, a commercially available dye, and brighter than the FDA-approved dye, indocyanine green (ICG). Full article
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(E)-3-[4-(1H-Imidazol-1-yl)phenyl]-1-(4-methylphenyl)prop-2-en-1-one
Molbank 2021, 2021(3), M1269; https://doi.org/10.3390/M1269 - 10 Aug 2021
Cited by 1 | Viewed by 1223
Abstract
Imidazole-containing chalcones have been shown to be strongly effective against Aspergillusfumigatus, the causative agent for the disease pulmonary aspergillosis. Claisen–Schmidt condensation of 4-(1H-imidazol-1-yl)benzaldehyde with 4′-methylacetophenone using aqueous sodium hydroxide in methanol yielded the novel compound (E)-3-[4-(1H [...] Read more.
Imidazole-containing chalcones have been shown to be strongly effective against Aspergillusfumigatus, the causative agent for the disease pulmonary aspergillosis. Claisen–Schmidt condensation of 4-(1H-imidazol-1-yl)benzaldehyde with 4′-methylacetophenone using aqueous sodium hydroxide in methanol yielded the novel compound (E)-3-[4-(1H-imidazol-1-yl)phenyl]-1-(4-methylphenyl)prop-2-en-1-one in good yield and purity after recrystallization from hot methanol. With the known antifungal properties of these combined pharmacophores, this novel compound is suitable for anti-aspergillus activity study. Full article
(This article belongs to the Section Organic Synthesis)
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(±)-2-{[4-(4-Bromophenyl)-5-phenyl-4H-1,2,4-triazol-3-yl]sulfanyl}-1-phenyl-1-ethanol
Molbank 2021, 2021(3), M1268; https://doi.org/10.3390/M1268 - 06 Aug 2021
Viewed by 1458
Abstract
The novel racemic secondary alcohol (±)-2-{[4-(4-bromophenyl)-5-phenyl-4H-1,2,4-triazol-3-yl]sulfanyl}-1-phenyl-1-ethanol (12) has been successfully synthesized through S-alkylation of 4-(4-bromophenyl)-5-phenyl-4H-1,2,4-triazole-3-thiol (10) in alkaline medium with 2-bromo-1-phenylethanone followed by reduction of the corresponding ketone 11. All the synthesized compounds [...] Read more.
The novel racemic secondary alcohol (±)-2-{[4-(4-bromophenyl)-5-phenyl-4H-1,2,4-triazol-3-yl]sulfanyl}-1-phenyl-1-ethanol (12) has been successfully synthesized through S-alkylation of 4-(4-bromophenyl)-5-phenyl-4H-1,2,4-triazole-3-thiol (10) in alkaline medium with 2-bromo-1-phenylethanone followed by reduction of the corresponding ketone 11. All the synthesized compounds were characterized by IR, 1D (1H, 13C, DEPT135) and 2D (1H-1H, 1H-13C and 1H-15N) NMR spectroscopy, elemental analysis and HRMS spectrometry. Full article
(This article belongs to the Section Organic Synthesis)
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2-Diphenylphosphinomethyl-3-methylpyrazine
Molbank 2021, 2021(3), M1267; https://doi.org/10.3390/M1267 - 05 Aug 2021
Viewed by 1475
Abstract
The lateral metalation-electrophilic trapping reaction of alkyl-substituted pyrazines has always been challenging and poorly regioselective, with the corresponding derivatives often being isolated in moderate yield. In this contribution, we first report on the preparation of an unsymmetrically-substituted pyrazine, that is 2-diphenylphosphinomethyl-3-methylpyrazine, by subjecting [...] Read more.
The lateral metalation-electrophilic trapping reaction of alkyl-substituted pyrazines has always been challenging and poorly regioselective, with the corresponding derivatives often being isolated in moderate yield. In this contribution, we first report on the preparation of an unsymmetrically-substituted pyrazine, that is 2-diphenylphosphinomethyl-3-methylpyrazine, by subjecting to metalation with n-BuLi the commercially available 2,3-dimethylpyrazine, followed by interception of the putative lithiated benzyl-type intermediate with Ph2PCl. Such a functionalization has been successfully carried out in the absence of additional ligands, working either in THF at −78 °C or in a more environmentally friendly solvent like cyclopentyl methyl ether at 0 °C, with the desired phosphine derivative being isolated in 70–85% yield. The newly synthesized adduct has been fully characterized by means of multinuclear magnetic resonance spectroscopic techniques, and also by preparing a selenium derivative, which furnished single crystals that were suitable for X-ray analysis. Full article
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Communication
4-Aminoalkyl Quinolin-2-one Derivatives via Knorr Cyclisation of ω-Amino-β-Keto Anilides
Molbank 2021, 2021(3), M1266; https://doi.org/10.3390/M1266 - 05 Aug 2021
Cited by 1 | Viewed by 1419
Abstract
In a high-yielding and solvent-free procedure N-ethoxycarbonyl protected ω-amino-β-keto anilides undergo Knorr cyclisation in neat polyphosphoric acid to provide straightforward route to 4-aminoalkyl quinolin-2-one derivatives with variable length of the alkyl chain. Full article
(This article belongs to the Section Organic Synthesis)
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4-Chlorobenzyl Chloride
Molbank 2021, 2021(3), M1265; https://doi.org/10.3390/M1265 - 04 Aug 2021
Viewed by 1363
Abstract
The X-ray structure of the title compound has been determined for the first time. Its molecular structure is in good agreement with those previously determined for similar benzyl halides and the angles between the ring–Cl bonds in adjacent molecules show values in good [...] Read more.
The X-ray structure of the title compound has been determined for the first time. Its molecular structure is in good agreement with those previously determined for similar benzyl halides and the angles between the ring–Cl bonds in adjacent molecules show values in good agreement with an early Zeeman quadrupole spectroscopy study. Full article
(This article belongs to the Section Structure Determination)
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2-Hydroxy-3-octyloxybenzaldehyde
Molbank 2021, 2021(3), M1264; https://doi.org/10.3390/M1264 - 03 Aug 2021
Viewed by 1430
Abstract
Herein, we report the chromatography-free synthesis of 2-hydroxy-3-octyloxybenzaldehyde by the alkylation of 2,3-dihydroxybenzaldehyde as a promising precursor for new SalEn-type complexes with transition metals. The structure of the product is elucidated by means of 1H and 13C-NMR spectra, high-resolution mass spectrometry [...] Read more.
Herein, we report the chromatography-free synthesis of 2-hydroxy-3-octyloxybenzaldehyde by the alkylation of 2,3-dihydroxybenzaldehyde as a promising precursor for new SalEn-type complexes with transition metals. The structure of the product is elucidated by means of 1H and 13C-NMR spectra, high-resolution mass spectrometry with electrospray ionization (ESI-HRMS) and Fourier-transform infrared spectroscopy (FTIR). Full article
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4′,4′′′,4′′′′′-Nitrilotris(4-methoxy-[1,1′-biphenyl]-3-carbaldehyde)
Molbank 2021, 2021(3), M1263; https://doi.org/10.3390/M1263 - 31 Jul 2021
Viewed by 1699
Abstract
Multipodal salicylaldehydes have attracted much scientific interest as scaffolds for the construction of multinuclear complexes, as well as metal and covalent organic frameworks. Herein, we report a preparation of 4′,4′′′,4′′′′′-nitrilotris(4-methoxy-[1,1′-biphenyl]-3-carbaldehyde), a direct precursor for the tripodal salicylaldehyde with triphenylamine core. The structure of [...] Read more.
Multipodal salicylaldehydes have attracted much scientific interest as scaffolds for the construction of multinuclear complexes, as well as metal and covalent organic frameworks. Herein, we report a preparation of 4′,4′′′,4′′′′′-nitrilotris(4-methoxy-[1,1′-biphenyl]-3-carbaldehyde), a direct precursor for the tripodal salicylaldehyde with triphenylamine core. The structure of the product was confirmed by molecular spectroscopy. The reported approach may be broadened over a variety of multipodal salicylaldehydes. Full article
(This article belongs to the Section Organic Synthesis)
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1-Tosyl-6-vinyl-4,5,6,7-tetrahydro-1H-benzo [d] imidazole-2-amine
Molbank 2021, 2021(3), M1262; https://doi.org/10.3390/M1262 - 31 Jul 2021
Viewed by 1698
Abstract
The alkene functionalised 2-aminobenzimidazole ring found in terrazoanthine natural products was synthesized in 3 steps from 1,2-epoxy-4-vinylcyclohexane via epoxide ring opening with toluenesulphonamide yielding 2 regioisomeric, separable amino alcohols. One isomer was oxidized to the corresponding ketone and subsequently condensed with cyanamide to [...] Read more.
The alkene functionalised 2-aminobenzimidazole ring found in terrazoanthine natural products was synthesized in 3 steps from 1,2-epoxy-4-vinylcyclohexane via epoxide ring opening with toluenesulphonamide yielding 2 regioisomeric, separable amino alcohols. One isomer was oxidized to the corresponding ketone and subsequently condensed with cyanamide to furnish the title compound, which was characterized by 1H-NMR and 13C-NMR spectroscopy. Full article
(This article belongs to the Section Organic Synthesis)
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4,4′-Di-tert-butyl-2,2′-bipyridinium Trifluoromethanesulfonate
Molbank 2021, 2021(3), M1261; https://doi.org/10.3390/M1261 - 28 Jul 2021
Viewed by 1863
Abstract
4,4′-Di-tert-butyl-2,2′-bipyridinium trifluoromethanesulfonate was synthesized by stirring 4,4′-Di-tert-butyl-2,2′-bipyridine with scandium(III) trifluoromethanesulfonate in acetonitrile, followed by precipitation with diethyl ether. The structure of the new compound was characterized by FT-IR, 1H, 13C{1H} and 19F{1H} [...] Read more.
4,4′-Di-tert-butyl-2,2′-bipyridinium trifluoromethanesulfonate was synthesized by stirring 4,4′-Di-tert-butyl-2,2′-bipyridine with scandium(III) trifluoromethanesulfonate in acetonitrile, followed by precipitation with diethyl ether. The structure of the new compound was characterized by FT-IR, 1H, 13C{1H} and 19F{1H} NMR spectroscopy and CHN elemental analysis. This is a safe and simple method to obtain mono-protonated bipyridinium trifluoromethanesulfonate without the direct use of trifluoromethanesulfonic acid. Full article
(This article belongs to the Section Organic Synthesis)
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N-(Benzo[d]thiazol-2-yl)-2-(2-fluoro-[1,1′-biphenyl]-4-yl)propanamide
Molbank 2021, 2021(3), M1260; https://doi.org/10.3390/M1260 - 26 Jul 2021
Viewed by 1321
Abstract
N-(Benzo[d]thiazol-2-yl)-2-(2-fluoro-[1,1′-biphenyl]-4-yl)propanamide was prepared by a reaction between benzo[d]thiazol-2-amine and flurbiprofen in high yield. The newly obtained flurbiprofen derivative was fully analyzed and characterized via 1H, 13C, UV, IR, and mass spectral data. Full article
(This article belongs to the Section Structure Determination)
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Poly[3-methyl-1,3-oxazolidin-2-iminium[µ3-cyanido-tri-µ2-cyanido-κ9C:N-tricuprate(I)]]
Molbank 2021, 2021(3), M1259; https://doi.org/10.3390/M1259 - 26 Jul 2021
Viewed by 1261
Abstract
The unexpected formation of an oxazole ring has occurred during synthesis of a copper(I) cyanide network polymer as part of our ongoing studies of the structural chemistry of these networks. Crystals of the title compound were formed during the synthesis of a previously [...] Read more.
The unexpected formation of an oxazole ring has occurred during synthesis of a copper(I) cyanide network polymer as part of our ongoing studies of the structural chemistry of these networks. Crystals of the title compound were formed during the synthesis of a previously reported CuCN network solid containing protonated N-methylethanolamine and have been characterized by single crystal X-ray structure analysis. The structure shows well-defined oxazole-2-iminium cations sitting in continuous channels along the short a-axis of the crystal in a new three-dimensional copper(I) cyanide polymeric network. Evidently, a reaction has occurred between the cyanide ion and the protonated N-methylethanolamine base. Full article
(This article belongs to the Special Issue Molecules from Side Reactions II)
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Communication
2-Hydroxy-5-(3,5,7-trihydroxy-4-oxo-4H-chromen-2-yl)phenyl (E)-3-(4-hydroxy-3-methoxyphenyl)acrylate: Synthesis, In Silico Analysis and In Vitro Pharmacological Evaluation
Molbank 2021, 2021(3), M1258; https://doi.org/10.3390/M1258 - 23 Jul 2021
Cited by 1 | Viewed by 1363
Abstract
Quercetin and ferulic acid are two phytochemicals extensively represented in the plant kingdom and daily consumed in considerable amounts through diets. Due to a common phenolic structure, these two molecules share several pharmacological properties, e.g., antioxidant and free radical scavenging, anti-cancer, anti-inflammatory, anti-arrhythmic, [...] Read more.
Quercetin and ferulic acid are two phytochemicals extensively represented in the plant kingdom and daily consumed in considerable amounts through diets. Due to a common phenolic structure, these two molecules share several pharmacological properties, e.g., antioxidant and free radical scavenging, anti-cancer, anti-inflammatory, anti-arrhythmic, and vasorelaxant. The aim of the present work was the combination of the two molecules in a single chemical entity, conceivably endowed with more efficacious vasorelaxant activity. Preliminary in silico studies herein described suggested that the new hybrid compound bound spontaneously and with high affinity on the KCa1.1 channel. Thus, the synthesis of the 3′-ferulic ester derivative of quercetin was achieved and its structure confirmed by 1H- and 13C-NMR spectra, HSQC and HMBC experiments, mass spectrometry, and elementary analysis. The effect of the new hybrid compound on vascular KCa1.1 and CaV1.2 channels revealed a partial loss of the stimulatory activity that characterizes the parent compound quercetin. Therefore, further studies are necessary to identify a better strategy to improve the vascular properties of this flavonoid. Full article
(This article belongs to the Special Issue Innovative Approaches to Modify Polyphenols)
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N-(2,2-Diphenylethyl)-2-(6-methoxynaphthalen-2-yl)propanamide
Molbank 2021, 2021(3), M1257; https://doi.org/10.3390/M1257 - 23 Jul 2021
Viewed by 1442
Abstract
N-(2,2-Diphenylethyl)-2-(6-methoxynaphthalen-2-yl)propanamide was prepared by a reaction between 2,2-diphenylethan-1-amine and naproxen in high yield. The newly obtained naproxen derivative was fully analyzed and characterized via 1H, 13C, UV, IR, and mass spectral data. Full article
(This article belongs to the Section Structure Determination)
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9a-Phenyl-2,3,3a,3b,9a,9b-hexahydro-4H-furo[3‘,2’:3,4]cyclobuta- [1,2-b]chromen-4-one: A Flavone-Based [2 + 2]-Photocycloadduct
Molbank 2021, 2021(3), M1256; https://doi.org/10.3390/M1256 - 23 Jul 2021
Cited by 3 | Viewed by 1577
Abstract
The intermolecular [2 + 2]-photocycloaddition of the parent flavone molecule (4) as the triplet energy-accepting species and the electron-rich alkene 2, 3-dihydrofuran (5) was performed by visible-light-mediated triplet-sensitization with an iridium-based organometallic sensitizer. The reaction proceeds with high diastereo- [...] Read more.
The intermolecular [2 + 2]-photocycloaddition of the parent flavone molecule (4) as the triplet energy-accepting species and the electron-rich alkene 2, 3-dihydrofuran (5) was performed by visible-light-mediated triplet-sensitization with an iridium-based organometallic sensitizer. The reaction proceeds with high diastereo- and regioselectivity (>98:2 for the regiochemical orientation and with 95% d.s.). In contrast to numerous other ene/enone combinations that are described in the literature and were also performed by us, the reaction between 4 and 5 almost solely afforded the cis-syn-cis cyclobutane 6, whereas analogous conjugated six- and five-membered cycloalkenones preferentially react to cis-anti-cis cyclobutanes or a mixture of both diastereoisomers (e.g., for the cyclohexanone-derived example 9). Full article
(This article belongs to the Section Organic Synthesis)
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N,N-Bis(hexyl α-d-acetylmannosyl) Acrylamide
Molbank 2021, 2021(3), M1255; https://doi.org/10.3390/M1255 - 22 Jul 2021
Viewed by 1586
Abstract
Glycosyl monomers for the assembly of multivalent ligands are typically synthesized using carbohydrates with biological functions and polymerizable functional groups such as acrylamide or styrene introduced into the carbohydrate aglycon, and monomers polymerized using a radical initiator. Herein, we report the acryloylation of [...] Read more.
Glycosyl monomers for the assembly of multivalent ligands are typically synthesized using carbohydrates with biological functions and polymerizable functional groups such as acrylamide or styrene introduced into the carbohydrate aglycon, and monomers polymerized using a radical initiator. Herein, we report the acryloylation of 6-aminohexyl α-d-mannoside and its conversion into the glycosyl monomer bearing an acrylamide group. The general acryloylation procedure afforded the desired N-hexyl α-d-acetylmannosyl acrylamide monomer as well as an unexpected compound with a close Rf value. The compounds were separated and analyzed by nuclear magnetic resonance spectroscopy and mass spectrometry, which revealed the unknown compound to be the bivalent N,N-bis(hexyl α-d-acetylmannosyl) acrylamide monomer, which contains two hexyl mannose units and one acrylamide group. To the best of our knowledge, this side reaction has not previously been disclosed, and may be useful for the construction of multivalent sugar ligands. Full article
(This article belongs to the Special Issue Molecules from Side Reactions II)
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Short Note
Thiophene-3-carbonyl Chloride
Molbank 2021, 2021(3), M1254; https://doi.org/10.3390/M1254 - 22 Jul 2021
Viewed by 1253
Abstract
The X-ray structure of the title compound has been determined for the first time. It shows the ring flip disorder common among thiophene-3-carbonyl derivatives and the occurrence of this phenomenon in the structures of such compounds is discussed. Full article
(This article belongs to the Section Structure Determination)
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4-Chloro-6-(chloromethyl)-1-methyl-1H-pyrazolo[3,4-d]pyrimidine
Molbank 2021, 2021(3), M1253; https://doi.org/10.3390/M1253 - 22 Jul 2021
Cited by 2 | Viewed by 1371
Abstract
A novel 4-chloro-6-(chloromethyl)-1-methyl-1H-pyrazolo[3,4-d]pyrimidine was prepared by a rational and short two-step synthesis from commercially available ethyl 5-amino-1-methyl-1H-pyrazole-4-carboxylate via 6-(chloromethyl)-1-methyl-1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-one. The structure of the synthesized compounds was established by elemental analysis, high-resolution mass-spectrometry, 1 [...] Read more.
A novel 4-chloro-6-(chloromethyl)-1-methyl-1H-pyrazolo[3,4-d]pyrimidine was prepared by a rational and short two-step synthesis from commercially available ethyl 5-amino-1-methyl-1H-pyrazole-4-carboxylate via 6-(chloromethyl)-1-methyl-1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-one. The structure of the synthesized compounds was established by elemental analysis, high-resolution mass-spectrometry, 1H, 13C-NMR and IR spectroscopy and mass-spectrometry. 4-Chloro-6-(chloromethyl)-1-methyl-1H-pyrazolo[3,4-d]pyrimidine is a convenient intermediate for various disubstituted 1-methyl-1H-pyrazolo[3,4-d]pyrimidines, which may be of interest as substances with useful pharmacological properties. Full article
(This article belongs to the Section Organic Synthesis)
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1-(4-Formyl-2,6-dimethoxyphenoxy)-4-chlorobut-2-yne
Molbank 2021, 2021(3), M1252; https://doi.org/10.3390/M1252 - 21 Jul 2021
Viewed by 1164
Abstract
A reaction of biomass-derived aldehyde synringaldehyde and half an equivalent of 1,4-dichlorobut-2-yne was attempted in order to obtain a bis-aldehyde with an alkyne spacer. The reaction was carried out in a basic media to effect bis O-alkylation, as described in literature for [...] Read more.
A reaction of biomass-derived aldehyde synringaldehyde and half an equivalent of 1,4-dichlorobut-2-yne was attempted in order to obtain a bis-aldehyde with an alkyne spacer. The reaction was carried out in a basic media to effect bis O-alkylation, as described in literature for the preparation of structurally similar compounds. Nevertheless, only mono alkylation was observed. Full article
(This article belongs to the Section Organic Synthesis)
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Communication
Synthesis of Aminopropyltriethoxysilyl-Substituted Imines and Amides
Molbank 2021, 2021(3), M1251; https://doi.org/10.3390/M1251 - 18 Jul 2021
Cited by 2 | Viewed by 1661
Abstract
A series of small molecules containing aminopropyltriethoxysilyl-substituted imines and amides were synthesized so that they could potentially be incorporated into self-assembled monolayers (SAMs) on metal oxide surfaces. Simple one-step imine preparations and two-step amide preparations are reported here. Full article
(This article belongs to the Section Organic Synthesis)
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