Synthesis of some novel pyrazolo[1,5-a]pyrimidine, 1,2,4-triazolo[1,5-a]pyrimidine, pyrido[2,3-d]pyrimidine, pyrazolo[5,1-c]-1,2,4-triazine and 1,2,4-triazolo[5,1-c]-1,2,4-triazine derivatives incorporating a thiazolo[3,2-a]benzimidazole moiety

✍ Scribed by Hatem A. Abdel-Aziz; Nehal A. Hamdy; Issa M. I. Fakhr; Ahmad M. Farag

• Publisher: Journal of Heterocyclic Chemistry
• Year: 2008
• Tongue: English
• Weight: 407 KB
• Volume: 45
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570450413

✦ Synopsis

Abstract

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E‐3‐(N,N‐Dimethylamino)‐1‐(3‐methylthiazolo[3,2‐a]benzimidazol‐2‐yl)prop‐2‐en‐1‐one (2) was synthesized by the reaction of 1‐(3‐methylthiazolo[3,2‐a]benzimidazol‐2‐yl)ethanone (1) with dimethylformamide‐dimethylacetal. The reaction of 2 with 5‐amino‐3‐phenyl‐1__H__‐pyrazole (4a) or 3‐amino‐1,2,4‐(1__H__)‐triazole (4b) furnished pyrazolo[1,5‐a]pyrimidine and 1,2,4‐triazolo[1,5‐a]pyrimidine derivatives 6a and 6b, while the reaction of enaminone 2 with 6‐aminopyrimidine derivatives 7a,b afforded pyrido[2,3‐d]pyrimidine derivatives 9a,b, respectively. The diazonium salts 11a or 11b coupled with compound 2 to yield the pyrazolo[5,1‐c]‐1,2,4‐triazine and 1,2,4‐triazolo[5,1‐c]‐1,2,4‐triazine derivatives 13a and 13b. Some of the newly synthesized compounds exhibited a moderate effect against some bacterial and fungal species.