Synthesis of α-methyl-β-(3-methylpyrazol-1-yl)-and α-methyl-β-(5-methylpyrazol-1-yl)propionic acids and their esterification with vinyl acetate

α-Methyl-β-(3-methylpyrazol-1-yl)-and α-methyl-β-(5-methylpyrazol-1-yl)propionic acids were synthesized by reaction of 3(5)-methylpyrazole with methyl methacrylate, followed by separation of the resulting isomeric esters and their hydrolysis. Esterification of the title acids was performed via vinyl exchange reaction with vinyl acetate in the catalytic system mercury acetate-trifluoroacetic acid.     

Phase-transfer catalyzed alkylation of pyrazoles and 1,2,4-triazole with cis- and trans-1,4-dichloro-2-butenes

The phase-transfer catalyzed (PTC) alkylation of pyrazoles and 1,2,4-triazole with cis- and trans-1,4-dichloro-2-butenes (DCB) has been examined. The monoalkylation products of pyrazoles with cis-DCB are bicyclic salts formed by intramolecular cyclization of the intermediate cis-1-(4-chloro-2-butenyl)pyrazoles. The corresponding trans-compounds are incapable of cyclization, but on prolonged standing they undergo intermolecular polyquaternization. Both cis- and trans-DCB undergo phase-transfer catalyzed reaction with 1,2,4-triazole to give polymeric quaternary salts. Conditions have been worked out for the dehydrochlorination of 1-(4-chloro-2-butenyl)azoles to 1-(butadien-2-yl)azoles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 497–503, April, 1989.     

Reactions of Secondary Amines with Dichlorocarbene Generated in Aqueous–Alkaline Medium in the Presence of N-Methylmorpholine N-Oxide

Russian Journal of Organic Chemistry - Dichlorocarbene generated from chloroform in aqueous–alkaline medium in the presence of N-methylmorpholine N-oxide is converted to phosgene which reacts...     

1-Vinyl-3- and 1-vinyl-5-pyrazolecarboxylic acids. Synthesis and anti-burn activity of their chitosan salts

The synthesis of 1-vinyl-3- and 1-vinyl-5-pyrazolcarboxylic acids is developed and the anti burn activity of the chitosan salts of 1-vinyl-3(5)-carboxylic acids is studied.