Azabenzocycloheptenones. Part XIV. Cyclisation of amino-acid derivatives to tetrahydro-1-benzazepin-5-ones and tetrahydroquinolin-4-ones

Abstract

Dieckmann cyclisation of methyl 3-(o-methoxycarbonylanilino)propionate (IV; R¹= H, R²= R³= Me, n= 2) gives methyl 1,2,3,4-tetrahydro-4-oxoquinoline-3-carboxylate (V), some reactions of which are recorded. Similar cyclisation of the N-acetyl derivative of ethyl 4-(o-methoxycarbonylanilino)butyrate (IV; R¹= H, R²= Me, R³= Et, n= 3) gives ethyl 1-acetyl-1,2,3,4-tetrahydro-5-oxo-1-benzazepine-4-carboxylate (III; R¹= Ac, R²= CO₂Et, R³= H). Various N-methyl and N-phenyl derivatives of 4-anilinobutyric acid (XII; R¹= R²= R³= H) can be cyclised by phosphoryl chloride in refluxing benzene to give derivatives of 1-methyl and 1-phenyl-1,2,3,4-tetrahydro-1-benzazepin-5-one.