Synthesis and biological evaluation of novel pyrimidines derived from 6-aryl-5-cyano-2-thiouracil

Starting from 6-aryl-5-cyano-2-thiouracil derivative 1a-f, a series of novel thiazolo[3,2-a]pyrimidines 4a-f were synthesized. The mechanism and the regioselectivity of the studied reactions are discussed. In addition, a series of tetrahydro-4-H-pyrimido[2,1-b][1,3]thiazines 7a-e and 2-((ethoxymethyl)thio)-4-aryl-1,6-dihydropyrimidines 9b,c,e were synthesized. The anti-microbial activities of some of the prepared compounds were screened, and the results revealed that compounds 3c and 4c were more active than the standard (Ampicillin) against gram positive bacteria (Pseudomonas aeruginosa). Moreover, compounds 4b,e and 3f were found to be good antifungal agents against the studied fungal strains.