Molecules 2001, 6, 574-587 molecules ISSN 1420-3049 http://www.mdpi.org One-Pot Quinazolin-4-ylidenethiourea Synthesis via N-(2- Cyanophenyl)benzimidoyl isothiocyanate Walid M. Fathalla. 1 , Michal Čajan 1,2 , Jaromír Marek 3 and Pavel Pazdera 1, * 1 Department of Organic Chemistry, Faculty of Science, Masaryk University, Brno, Czech Republic, Tel.: +420 5 41129305, Fax: +420 5 41211214. 2 National Center for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic. 3 Department of Inorganic Chemistry, Masaryk University, 611 37 Brno, The Czech Republic *Author to whom correspondence should be addressed; E-mail: pazdera@chemi.muni.cz. Received: 10 November 2000; in revised form 22 May 2001 / Accepted: 23 May 2001 / Published: 30 June 2001 Abstract: 1,1-Disubstituted-3-(2-phenyl-3H-quinazolin-4-ylidene)thioureas (8) were synthesized in a one pot reaction of N-(2-cyanophenyl)benzimidoyl isothicyanate (3) with secondary amines. The products underwent transamination reactions. Compounds 8a-8g were identified by FTIR, 1 H-NMR, 13 C-NMR, mass spectroscopy and X-ray crystallography. Keywords: N-(2-cyanophenyl)benzimidoyl isothicyanate, 1,1-disubstituted-3-(2-phenyl- 3H-quinazolin-4-ylidene)thioureas, intramolecular cycloaddition, 1,1-disubstituted-3-[(2- cyanophenylimino)phenylmethyl]thioureas, quinazolines. Introduction The benzodiazocines [1] and quinazolines [2,3] represent two classes of heterocyclic compounds with diverse physiological activities, e.g., acting as central nervous system depressants and calcium sensitizing agents. Several quinazoline derivatives have been tested for their biological and pharmacological activities. These derivatives posses hypnotic [4], diuretic [5], antihistaminic [6], anti-