SYNTHESIS AND STRUCTURE OF NEW PYRIDO[2,3-D]PYRIMIDINE DERIVATIVES WITH CALCIUM-CHANNEL ANTAGONIST ACTIVITY

Several series of pyrido[2,3-d]pyrimidine derivatives were synthesized by reaction of aryl methyleneacetoacetates with different aminopyrimidines. The solid-state structure of the methyl 5-(3'-chlorophenyl)-7-methyl-4-oxo-2-thioxo-1,2,3,4,5,8-hexahydropyrido[2,3-d]pyrimidine-6-carboxylate shows that these compounds can adopt some of the most important structural features of the 1,4-dihydropyridine calcium channel blockers. The scope and limitations of the synthetic procedure with different aminoheterocycles is presented together with the initial evaluation of their calcium antagonistic activity by comparison with the usual reference compound nifedipine.