Methane → 12b-Hydroxy-10,11-dimethoxy-5,6,8,12b-tetrahydro-isoindolo[1,2-a]isoquinol-8-one

Participants

Reaction Conditions

Reaction Steps

10,11-Dimethoxy-5,6,8,12b-tetrahydro-isoindolo-[1,2-a]isoquinoline (109.65 g) and potassium hydroxide in pellet form (23.2 g) are dissolved in methanol (1100 cc). Air is bubbled into the reaction mixture, which is heated under reflux for 3 hours and then maintained at 25° C. for 48 hours. After concentration to 500 cc, the addition of distilled water (5000 cc) and stirring for 2 hours, a precipitate appears which is filtered off, washed three times with distilled water (total 500 cc) and dried under reduced pressure (20 mm Hg) at 40° C. A crude product (104.65 g), melting at 219° C., is obtained. A solution of a portion of this product (30 g) in dimethylformamide (200 cc) at 120° C. is treated with decolourising charcoal (1 g), filtered whilst hot, and cooled at about 5° C. for 16 hours. The resulting crystals are filtered off, washed three times with diisopropyl ether (total 30 cc) and dried under reduced pressure (1 mm Hg) at 60° C. for 6 hours. 12b-Hydroxy-10,11-dimethoxy-5,6,8,12b-tetrahydro-isoindolo[1,2-a]isoquinol-8-one (16.70 g), melting at 220° C., is thus obtained.

Provenance & Evidence