Polycyclic N‐heterocyclic compounds. XLV. Synthesis of 4‐substituted 5,6‐dihydrobenzo[h]quinazolines and 6,7‐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 6,7‐dihydro‐5H‐benzo[6,7]cyclohepta‐[1,2‐d]pyrimidines with substituents which are an electron‐attracting group such as a nitrite, an amide, a thione, or a carboxyl group is described. Their inhibitory activity against collagen‐induced platelet aggregation was also investigated.