摘要 |
<p>The invention relates to a process for the preparation of 1-alkyl-1,2,3,4-tetrahydroisoquinoline derivatives of the general formula <IMAGE> (1) The compounds can be used for the preparation of tetrahydroisoquinolines of the reticuline type, or of the norreticuline type, by reductive removal of the OH groups or, if they carry an acyl protective group on the nitrogen, for the preparation of isoquinolines of the papaverine type by acid-catalyzed hydrolysis with removal of the acyl groups and simultaneous removal of the hydroxyl groups. These 1-alkyl-1,2-dihydroisoquinoline derivatives can then be used for the preparation of isoquinolines of the papaverine type by aromatization by means of acids or hydrazine.</p> |