PolycyclicN-Hetero Compounds. XLII: Convenient Syntheses of 6, 7-Dihydro-5H-pyrido[2,3-b]pyrimido[4,5-d]azepine as a Novel Polyheterocyclic Ring System and Its 4-Substituted Derivatives
PolycyclicN-Hetero Compounds. XLII: Convenient Syntheses of 6, 7-Dihydro-5H-pyrido[2,3-b]pyrimido[4,5-d]azepine as a Novel Polyheterocyclic Ring System and Its 4-Substituted Derivatives