Hydrochloric Acid → 4-(Isoquinolin-1-yl)-1-methylpiperidin-4-ol

Participants

Reaction Steps

346 g. of 1-methyl-4-benzoyloxy-4-(1-isoquinolyl)-piperidine hydrochloride (m.p. 269°, from isopropanol), obtainable by adding 30 g. of NaH in portions to a solution of 260 g. of 1-cyano-2-benzoyl-1,2-dihydroiosquinoline and 120 g. of 1-methylpiperidin-4-one in 950 ml. of dimethylformamide, with stirring, and allowing the mixture to stand overnight, are heated under reflux with 1,400 ml. of 25% hydrochloric acid for 40 hours. The mixture is cooled and worked up in the customary manner to give 1-methyl-4-(1-isoquinolyl)-piperidin-4-ol, m.p. 265°-266°.

Provenance & Evidence