Synthesis and biological evaluation of benzothiazole derivatives of pyrimidines, acrylonitriles, and coumarins.

A number of benzothiazole derivatives of 2-aminopyrimidines (3a-b, 5, 6a-b, and 7), benzothiazole-3-arylacrylonitriles (10a-c), and benzothiazol-2-yl-coumarins (18a c, and 20) were synthesized by reacting benzothiazole derivatives with dicarbonyl compounds, and aromatic aldehydes. The unexpected 2-(4-methoxyphenyl)benzo[d]thiazole (14) was obtained as a unique product via the reaction of 2-aminothiophenol with ethyl 3-(4-methoxyphenyl)-2-scyanoacrylate. 2-(Benzo[d]thiazol-2-yl)-3-(4-hydroxyphenyl)acrylonitrile (10a) exhibited activity against Staphylococcus aureus. 2-(Benzo[d]thiazol-2-ylamino)pyrimidine-4,6-(1H,5H)-dione (3b) showed antibacterial activity selectivity against Corynebacterium xerosis. 2-(Benzo[d]thiazol-2-ylamino)-6-methylpyrimidin-4(3H)-one (5) showed weak anti-fungal activity against Candida albicans.