Preparation of 1,2,4,5-tetrahydro-7-alkoxy-(and 7,8-dialkoxy)-3H,3-benzazepines and 3-substituted derivatives thereof from the corresponding phenethylamines

Abstract

Certain 1,2,4,5-tetrahydro-7-alkoxy-(and 7,8-dialkoxy)-3H,3-benzazepines are prepared in excellent yields by a three step process comprising reacting a 3-alkoxy-(or 3,4-dialkoxy)-phenethylamine with a halo-acetaldehyde dialkylacetal to form the corresponding N-(2,2-dialkoxyethyl) phenethylamine, reacting that product with BF.sub.3 to close the ring and to form a 1-alkoxy-1,2,3,4-tetrahydro-7-alkoxy-(or 7,8-dialkoxy)-3H,3-benzazepine and reacting that product under reductive cleavage conditions to remove the 1-alkoxy group and to obtain the desired benzazepine. The benzazepines can be further reacted in the known manner or in the manner disclosed herein to form certain 3-substituted benzazepines.

Dependencies are inferred from the claim text.