Synthesis of New Heterocyclic Systems on the Basis of 7-Benzyl-3-chloro-1-(morpholin-4-yl)-5,6,7,8-tetrahydro-2,7-naphthiridine-4-carbonitrile

Methods have been developed for the synthesis of new 8-amino-3-benzyl-5-(morpholin-4-yl)-1,2,3,4-tetrahydropyrimido4′,5′: 4,5]thieno2,3-c]2,7]naphthyridine starting from 7-benzyl-3-chloro-1-(morpholin-4-yl)-5,6,7,8-tetrahydro-2,7-naphthyridine-4-carbonitrile. 8-Hydrazinyl-3-benzyl-5-(morpholin-4-yl)-1,2,3,4-tetrahydropyrimido4′,5′: 4,5]thieno2,3-c]2,7]naphthyridine has been converted to isomeric pentacyclic structures with a triazole ring fused through the c] side of the pyrimidine ring, and their Dimroth rearrangement has been accomplished in both acidic and basic media. New heterocyclic systems containing pyrrolo1,2-a]pyrimidinone and pyrimido1,2-a]azepinone fragments were obtained on the basis of the thieno-2,3-c]2,7]naphthyridine derivative.