Process for the preparation of 1,2,3,4-tetrahydroisoquinoline derivatives

摘要

The novel tetrahydroisoquinolines of the formula I: wherein R1 and R2 denote hydrogen or lower alkyl, R3 denotes mercapto, lower alkylthio, sulphamoyl and mono- or disubstituted sulphamoyl-phenyl or a heterocyclic group and X denotes oxygen or sulphur, and their salts, are prepared by cleaving the protective group or groups from a correspondingly substituted 6,7-dihydroxytetrahydroisoquinoline, whose single hydroxyl group or whose two hydroxyl groups carry protective groups. The products of the process exert a relaxing action on smooth muscle; they may be used for the treatment of spastic disturbances of the visceral organ.