Methanesulfonic Acid → Rasagiline mesylate

Participants

Reaction Conditions

Reaction Steps

The toluenic phase of step (a) was charged into a 500 mL round-bottomed flask under nitrogen and equipped with mechanical stirring. 110 mL of acetonitrile were then added, followed by the dropwise addition of 32.54 g of methanesulfonic acid in about 20 minutes, maintaining the temperature below 40° C. Precipitation started after the addition of approximately 10% of the total amount of methanesulfonic acid. The thick suspension thus obtained was heated up to 75-80° C. and stirred for 30 min. The suspension was then cooled down to 10-15° C., stirred for at least 1 hour and filtered. The collected solid was washed with 3×20 mL of acetonitrile to yield 74.27 g of yellowish wet product (70.95 g of dry crude, partial yield: 86.20%; 99.32% by HPLC).

Provenance & Evidence