Rivastigmine → 2,3-dihydroxybutanedioic acid;[3-[(1S)-1-(dimethylamino)ethyl]phenyl] N-ethyl-N-methylcarbamate

Participants

Reaction Conditions

Reaction Steps

3 kg of rivastigmine freebase of Formula II in 105 lit of acetone, 1.8 kg of L-(+)-Tartaric acid was charged and heated to about 60° C. followed by stirring for about 30 minutes for complete dissolution. The resulting reaction solutions was passed through celite and wash the bed with 13.5 lit acetone to made particle free. The obtained clear solution was distilled off up to 50% of the initial volume and cooled to 30° C. 12 g of rivastigmine hydrogen tartrate was added and stirred for about 60 minutes. The reaction mixture was heated to reflux and stirred for about 60 minutes and cooled to about 30° C. and stirred for about 60 minutes for solid separation. The separated solid was filtered and washed the solid with 3 lit of acetone. Solid obtained was dried at about 60° C. for about 9 hours to afford 4.10 kg of the title compound.

Provenance & Evidence