Synthesis of 1,4,5,6-Tetrahydropyrazolo[3,4-d]pyrido[3,2-b]azepine

摘要

The synthesis of 7,-dihydro-5(6H)-quinolinone(3)from commercially available 3-amino-2-cyclohexen-1-one(1) and 3-(dimethylamino)acrolein(4)in 23% yield avoids the preparation of propynal(2). Conversion of 5-(4-methylphenylsulfonyl)-6,7,8,9-tetrahydro-5H-pyrido[3,2-b]azepine(12)to 6-(4-methylphenylsulfonyl)-1,4,5,6-tetrahydropyrazolo[3,4-d]pyrido[3,2-b]azepine(24)is described. Removal of the N-(4-methylphenylsulfonyl)group with 40% sulfuric acid in acetic acid gave the tricyclic azepine 26.Application of a similar series of reactions to 5-(4-nitrobenzoyl)-6,7,8,9-tetrahydro-5H-pyrido[3,2-b]-azepine(13)afforded 6-(4-nitrobenzoly)-1,4,5,6-tetrahydropyrazolo[3,4-d]pyrido[3,2-b]azepine(25).