N,N,N',N'-Tetramethylmethanediamine → Ondansetron

Participants

Reaction Steps

At −10° C., 4 ml of N,N,N′,N′-tetramethyldiaminomethane was slowly added to 46 ml of trifluoroacetic acid, which was then stirred for 30 min. 2.0 g of 1,2,3,9-tetrahydro-9-methyl-4H-carbazol-4-one and 8 g of 2-methyl imidazole was added to the reaction mixture, which was then stirred for about 8 hours at 120˜130° C. After completion of reaction, the reaction mixture was cooled at room temperature, and then 1N aq. sodium hydroxide was added thereto. The resulting solid was filtered and washed with water, and then dried. The resulting solid was suspended in 80 ml of methanol, and then 0.28 g of active carbon was added thereto, which was then stirred under reflux for 1 hour. The resulting mixture was filtered and washed with methanol, and then evaporated to give 2.2 g of 1,2,3,9-tetrahydro-9-methyl-3-[(2-methyl-1H-imidazol-1-yl)methyl]-4H-carbazol-4-one (yield 75%).

Provenance & Evidence