L. V. Andriyankova

Cyanoacetylenes in reaction with benzimidazol-2-one

The reaction of 1-phenyl-2-cyanoacetylene and 4-hydroxy-4-methyl-2-pentynenitrile with benzimidazol-2-one was studied. The respective N,N-diadducts were obtained. It was shown that the addition of benzimidazol-2-one to the tertiary cyanoacetylenic alcohol catalyzed by bases is accompanied by intramolecular cyclization.

Cyanoacetylenes in a reaction with benzoxazole-2-thione and benzoxazol-2-one

The reaction of benzoxazole-2-thione and benzoxazol-2-one with substituted cyanoacetylenes was studied. 2-[(3-Phenyl-2-propenenitrile)thio]benzoxazole was obtained by the reaction of benzoxazole-2-thione with phenylcyanoacetylene. Benzoxazol-2-one with phenylcyanoacetylene and a tertiary cyanoacetylenic alcohol gave the corresponding N-adducts.

Synthesis and x-ray structural analysis of 2-amino-4-cyanomethylene-5,5-dimethylthiazoline

The reaction of thiourea with 4-hydroxy-4-methyl-2-pentynenitrile in triethylamine is accompanied by heterocyclization and the formation of 2-amino-4-cyano-methylene-5, 5-dimethylthiazoline, whose structure was established by x-ray structural analysis (XSA).

Behavior of 4-hydroxy-4-methyl-2-pentynonitrile in water in the presence of lithium hydroxide

Conclusions4-Hydroxy-4-methyl-2-pentynonitrile is transformed by the action of LiOH in water to 2,2,4,4-tetramethyl-5-cyanomethylene-1,3-dioxolane and 5-amino-2,2-dimethyl-2,3-dihydro-3-furanone.

An unusual synthesis of substituted 1,3-oxazolidino [2,3-b] benzimidazoles

ConclusionsThe reactions of 2-alkyl- and 2-vinylthiobenzimidazoles with tertiary cyanoethynylcarbinols are accompanied by heterocyclization with formation of subsituted 1,3-oxazolidino[2, 3-b] benzimidazoles.

Synthesis of substituted 1,3-thiazinoazoles

Substituted 1,3-thiazinoazoles were obtained by treating benzimidazole-2-thione, 4,5-diphenylimidazole-2-thione, and 1,2,4-triazole-3-thione with tertiary cyanoacetylenic alcohols and their acetals in the presence of lithium hydroxide. Treatment of the 1,3-thiazinobenzimidazoles with base destroyed the thiazino ring forming benzimidazol-2-one.