Cerium (IV) ammonium nitrate-mediated reactions: Simple route to benzimidazole derivatives

AbstractThe reaction of o-phenylenediamine with aromatic aldehydes in MeOH at room temperature catalyzed by cerium (IV) ammonium nitrate (CAN) afforded either 2-aryl-1-arylmethyl-1H-benz-imidazoles and/or 2-aryl-substituted benzimidazoles

Pressure as effective green technology for synthesis of polyfunctionally substituted heteroaromatics: Synthesis of a variety of pyrazolo[1,5-a]pyrimidines

Pyrazole molecules are in the forefront of organic chemistry due to their various encompass substituents, which have many biological activity sequence. The biological and medicinal activities of pyrazolo[1,5-a]pyrimidines have received considerable interest in this regard. We reported here a comparison between reaction of 4-phenylazo-3,5-diaminopyrazole (4) with ethyl propiolate (15), dimethylacetylene dicarboxylate (20), diethyl fumarate (25) and benzylidenemalononitrile (11) in the presence of catalytic amount of piperidine. We initially followed literature procedure (method A), then utilizing ultrasound irradiation (method B), microwave heating (method C) and in a Q-tube (method D). We confirmed the structure of the product by analytical spectroscopic methods. Method (D) gave a good yield with a record reaction time

Multicomponent reactions under increased pressure: on the reaction of arylhydrazonals, aromatic aldehydes and malononitrile in Q-Tube

A novel multi-component reaction between arylhydrazonals, malononitrile and aromatic aldehydes under high pressure utilizing Q-tube was carried out. The reaction of arylhydrazonal (1j) with malononitrile and aromatic aldehydes afforded the corresponding biphenyl derivatives (4). However, compound 1h reacted with malononitrile and aromatic aldehydes (7) to afford pyridazino[5,4,3-de]1,6-naphthyridine-7-carbonitrile derivatives (8). In contrast, the arylhydrazonal (1k) at the same reaction conditions afforded the corresponding pyridazinoquinazoline derivative (22). A rationalization for the difference in behavior for reaction of compounds 1h-k with malononitrile and aromatic aldehydes was postulated. Based on these findings a mechanism to account for the formation of the reaction products is suggested excluding possible initial dimerization of malononitrile as has been previously reported

Cerium (IV) Ammonium Nitrate (CAN) Catalyzed One-pot Synthesis of 2-Arylbenzothiazoles

A one-pot synthesis of 2-arylbenzothiazoles from the reaction of 2-aminothiophenol and aromatic aldehydes catalysed by cerium (IV) ammonium nitrate (CAN) is reported

Article Cerium (IV) Ammonium Nitrate (CAN) Catalyzed One-pot Synthesis of 2-Arylbenzothiazoles

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Cerium (IV) Ammonium Nitrate (CAN) Catalyzed One-pot Synthesis of 2-Arylbenzothiazoles

A one-pot synthesis of 2-arylbenzothiazoles from the reaction of 2-aminothiophenol and aromatic aldehydes catalysed by cerium (IV) ammonium nitrate (CAN) is reported

Zn(L-proline)2: An efficient and reusable organocatalyst for the synthesis of polyfunctionally substituted pyrans and 2-amino-4-aryl-8-oxo-4,8-dihydropyrano[3,2-b]pyran derivatives

Efficient synthesis of non-annulated 2-amino-4H-pyrans and 2-amino-8-oxo-4,8-dihydropyrano[3,2-b]pyran derivatives, which are biologically relevant heterocycles is achieved, utilizing a domino three-component reaction of ethyl acetoacetate or kojic acid with aromatic aldehydes and malononitrile catalyzed by Zn(L-proline)2 as reusable organometallic catalyst. The process exhibits high atom economy, short reaction time, simple work up, high yields and environmentally friendly nature. Excellent yields of the targeted molecules have been obtained

Synthesis and Spectroscopic Properties of New Azo Dyes Derived from 3-Ethylthio-5-cyanomethyl-4-phenyl-1,2,4-triazole

New 1,2,4-triazole colorants were obtained, in high yields, by coupling 3-ethylthio-5-cyanomethyl-4-phenyl-1,2,4-triazole (1) with diazotized aniline derivatives 2, 4 and 6. The azo dyes prepared in this work may exist in three tautomeric forms. We found that the tautomerism is influenced mainly by the nature of substituent at the para position of the aniline coupling component. This tautomerisation was observed in the NMR spectra of the dyes. The dyes were characterized by IR, 1H-NMR, 13C-NMR and MS spectroscopic techniques

An efficient green synthesis of novel 1H-imidazo[1,2-a]imidazole-3-amine and imidazo[2,1-c][1,2,4]triazole-5-amine derivatives via Strecker reaction under controlled microwave heating

A highly efficient multi-component one-pot synthesis of novel 1H-imidazo[1,2-a]imidazole-3-amine and imidazo[2,1-c][1,2,4]triazole-5-amine derivatives has been developed through the reaction of easily available aromatic aldehydes, benzoyl cyanide and either 2-aminoimidazole-4,5-dicarbonitrile or 3-amino-1,2,4-triazole in pyridine under controlled microwave heating. The process is environmentally friendly, is operationally simple, with short reaction time and with high yields

Green and Highly Efficient Synthesis of 2-Arylbenzothiazoles Using Glycerol without Catalyst at Ambient Temperature

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