syntheses of diheterocyclic compounds based on 2-thioacetohydrazide-5,7-dimethyl-1,2,4-triazolo[1,5-a]- pyrimidine基于2-thioacetohydrazide-5 diheterocyclic化合物的合成,7-dimethyl-1,2,4-triazolo(1、5)-嘧啶.pdf

Molecules 2008, 13, 1353-1360; DOI: 10.3390/molecule OPEN ACCESS molecules ISSN 1420-3049 /molecules Article Syntheses of Diheterocyclic Compounds Based on 2-Thioacetohydrazide-5,7-dimethyl-1,2,4-triazolo[1,5-a]- pyrimidine Zu-Ming Liu, Qiong Chen, Chao-Nan Chen, Hai-Yang Tu * and Guang-Fu Yang Key Laboratory of Pesticide Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China; / * Author to whom correspondence should be addressed; E-mail: haiytu@ Received: 6 May 2008; in revised form: 26 May 2008 / Accepted: 26 May 2008 / Published: 13 June 2008 Abstract: The syntheses of some diheterocyclic compounds from 2-thioacetohydrazide- 5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine (1) are described. Compound 1 can be converted into triazoles, 1,3,4-oxadiazoles, and 1,3,4-thiadiazoles. The structures of the intermediates and the target compounds were confirmed by 1H-NMR, MS and elemental analyses. Keywords: 1,2,4-Triazolo[1,5-a]pyrimidine, triazole, 1,3,4-oxadiazole, 1,3,4-thiadiazoles Introduction The study of nitrogen-containing heterocycles is currently a hot topic in pesticide chemistry [1-7]. In particular the chemistry of 1,2,4-triazolo[1,5-a]pyrimidine derivatives has been of considerable interest for many years [8]. In 1935, 5-methyl-7-hydroxy-1,2,4-triazolo[1,5-a]pyrimidine was found to be an excellent stabilizer for photographic emulsions. Since then, var