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
1. Applied Organic Chemistry Department, National Research Centre, Dokki, Cairo 12622, Egypt;2. Department of Chemistry, Faculty of Science, Cairo University, Giza 12613, Egypt
Abstract:
E‐3‐(N,N‐Dimethylamino)‐1‐(3‐methylthiazolo3,2‐a]benzimidazol‐2‐yl)prop‐2‐en‐1‐one ( 2 ) was synthesized by the reaction of 1‐(3‐methylthiazolo3,2‐a]benzimidazol‐2‐yl)ethanone ( 1 ) with dimethylformamide‐dimethylacetal. The reaction of 2 with 5‐amino‐3‐phenyl‐1H‐pyrazole ( 4a ) or 3‐amino‐1,2,4‐(1H)‐triazole ( 4b ) furnished pyrazolo1,5‐a]pyrimidine and 1,2,4‐triazolo1,5‐a]pyrimidine derivatives 6a and 6b , while the reaction of enaminone 2 with 6‐aminopyrimidine derivatives 7a,b afforded pyrido2,3‐d]pyrimidine derivatives 9a,b , respectively. The diazonium salts 11a or 11b coupled with compound 2 to yield the pyrazolo5,1‐c]‐1,2,4‐triazine and 1,2,4‐triazolo5,1‐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.
