Their production process and production intermediates of 3,4-dihydroisoquinoline derivatives

A process for efficiently producing 3,4-dihydroisoquinoline derivatives, and to provide a useful production intermediate to them. The general formula (1) A method for producing in represented by 3,4-dihydroisoquinoline derivatives of general formula (3) In respect compound represented by either converted in the presence of an acid after reacting aniline derivatives, or in the general formula (3) compounds represented by is reacted with an aniline derivative in the presence of an acid conversion the method comprising.