Reactions of benzimidazole-2-thiol with N-alkyl-1-aza-1,3-enynes

Abstract

Reactions of N-alkyl-1-aza-1,3-enynes with benzimidazole-2-thiol in anhydrous dimethylformamide have been studied. The structure of the obtained compounds has been elucidated from the NMR data.

Reaction of tert-butylimine of phenylpropiolic aldehyde with substituted imidazole-2-thiones

“…Because of that, the structures of 2,7-diphenylimidazo-[2,1-b] [1,3]tiazine-5-tert-butylamine and 2,7-diphenyl-5H-imidazo[2,1-b][2,3]thiazin-5-ol, respectively, should be attributed to compounds IIIc and IVc. …”

“…The hydrolytic cleavage of tert-bytylamine from imidazo[2,1-b]-[1,3]thiazine-5-tert-bytylamines (IIIa-IIIc) is due to the presence of minor quantities of water in the solvent [3].…”

“…It has been shown earlier that the interaction of Ntert-butyl-1-aza-1,3-enes with substituted benzimidazole-2-thiols leads to the formation of polynuclear sulfur-containing heterocyclic compounds, viz., benzo [4,5]imidazole [2,1-b] [1,3]thiazin-4-ols [1,2].…”

“…As in case of substituted benzimidazole-2-thiols[1,2] the initially formed imidazo[2,1-b][1,3]thiazine-5tert-butylamines (IIIa-IIIc) undergo hydrolysis with the formation of imidazo[2,1-b][1,3]thiazin-5-ols (IVa-IVc). The hydrolytic cleavage of tert-bytylamine from imidazo[2,1-b]-[1,3]thiazine-5-tert-bytylamines (IIIa-IIIc) is due to the presence of minor quantities of water in the solvent[3].As a result of the addition of 4-phenyl-2-imidazole-2-thione (IIc) to imine I, the formation of two DOI: 10.1134/S1070363215030391 R = R 1 = Me (а); R = R 1 = Ph (b); R = H, R 1 = Ph (c).…”

Reactions of Aldehydes and Ketones and Their Derivatives

“…207 The kinetics of deuterium exchange have been measured for acetone over a range of solvents and temperatures, 208 and for acetone and 2-hydroxypropiophenone in deuteriomethanol. 209 Tautomeric equilibria in 2-, 4-, and 5-pyrimidones and their thio-and aza-analogues have been calculated. 210 Enolates Although kinetic protonation of many delocalized carbanions (including enolate anions) and of enols often takes place on the less hindered face (typically giving the less stable stereoisomer), an example of kinetic protonation on the more hindered side has been engineered via intramolecular proton transfer.…”