POLYCYCLIC N-HETEROCYCLIC COMPOUNDS .45. SYNTHESIS OF 4-SUBSTITUTED 5,6-DIHYDROBENZO[H]QUINAZOLINES AND -DIHYDRO-5H-BENZO[6,7]CYCLOHEPTA[1,2-D]PYRIMIDINES AND THEIR INHIBITORY ACTIVITY ON PLATELET-AGGREGATION

The synthesis of 4-substituted 5,6-dihydrobenzo[h]quinazolines and -di hydro-5H-benzo[6,7]cyclohepta[1,2-d]pyrimidines with substituents whic h are an electron-attracting group such as a nitrile, an amide, a thio ne, or a carboxyl group is described. Their inhibitory activity agains t collagen-induced platelet aggregation was also investigated.