ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Preparation and cyclization of 3-substituted 1-(2-cyanophenyl)-thioureas

P. Pazdera, D. Ondráček, and E. Nováček

Department of Organic Chemistry, Faculty of Natural Sciences, J. E. Purkyně University, CS-61137 Brno

Abstract: The reactions of 2-isothiocyanatobenzonitrile with ethyl-, tert-butyl-, cyclohexyl-, and benzylamine as well as with aniline, 4-toluidine, 4-anisidine, 4-bromoaniline, Phenylhydrazine, and hydrazine were studied. In dependence on the structure of the starting amine and on the reaction conditions either 3-substituted l-(2-cyanophenyl)thioureas, 3-substituted 4-imino-l,2,3,4-tetrahydroquinazoline-2-thiones or a mixture of both com­pounds were formed. 4-Amino-l,2-dihydroquinazoline-2-thione was formed in the reaction of 2-isothiocyanatobenzonitrile with ammonia. The structure of the latter was proved by an independent synthesis. 3-Substituted 1-(2-cyanophenyl)thioureas with the exception of the last were cyclized in boiling ethanol to corresponding 3-substituted 4-imino-1,2,3,4-tetrahydroquinazoline-2-thiones.

Full paper in Portable Document Format: 436a771.pdf

Chemical Papers 43 (6) 771–781 (1989)