Synthesis and Hypoglycemic Activity of 7, 8-Dihydro-6H-thiopyrano[3, 2-d]pyrimidine Derivatives and Related Compounds

A series of 2-amino-7, 8-dihydro-4-piperazinyl- and 4-amino-7, 8-dihydro-2-piperazinyl-6H-thiopyrano[3, 2-d]pyrimidines and related compounds were synthesized and evaluated for hypoglycemic activity. Several compounds exhibited excellent activity, and 7, 8-dihydro-2-(4-methyl-piperazinyl)-4-(1-pyrrolidinyl)- (8c, dimaleate : MTP-1307) and 2-amino-7, 8-dihydro-4-piperazinyl-6H-thiopyrano[3, 2-d]pyrimidine (18a, dimaleate : MTP-1403) were selected for further investigation.Oral administration of 8c and 18a at 50 mg/kg markedly improved oral glucose tolerance in ob/ob mice. In this test, buformin also showed activity, whereas tolbutamide produced no significant improvement.