Synthesis of basically substituted 5H-pyrimido[4,5-c]-2-benzazepines

Article abstract of DOI:10.1002/ardp.19933261104

The potentially CNS-active title compounds 19a-c can be prepared by a nine step synthesis beginning with phthalaldehydic acid. Knoevenagel condensation of 5 with the acetonitriles 2a-g and subsequent reduction with NaBH₄ lead to the dihydrocinnamic acid nitriles 3. Only 3a can be cyclized to the 2-benzazepinnitriles 9a,b. Ammonolysis of 9a yields the enaminonitrile 10, which is reacted with the orthoesters 11a-c to the imidic acid esters 12a-c. Ammonolysis leads to the tricycles 16a,b. After transformation of the lactam group in 16 to an imidoyl chloride 17, aminolysis with the amines 18a-c provides the title compounds 19a-c.