Abstract
Mannich reaction of 1-(3-hydroxy-4-methoxybenzyl)-6, 7-methylenedioxy-1, 2, 3, 4-tetrahydroisoquinoline (IX) at room temperature at pH 1.2, 6.0, 7.2, and 7.8 was examined and nandinine (II), 11-hydroxy-10-methoxy-2, 3-methylenedioxytetrahydroprotoberberine (X), and 9-hydroxy-12-hydroxymethyl-10-methoxy-2, 3-methy1enedioxytetrahydroprotoberberine (XI) were obtained in every case. Mannich reaction of 1-(3-hydroxy-4-methoxybenzyl)-6, 7-dimethoxy-1, 2, 3, 4-tetrahydroisoquinoline (XII) under heating in alkaline media also gave 9-hydroxy-12-hydroxymethyl-2, 3, 10-trimethoxy-7, 8, 13, 13a-tetrahydroprotoberberine (XIII).
