Methanesulfonic Acid → Tirbanibulin Mesylate

Participants

Reaction Conditions

Reaction Steps

KX2-391 (520 g, 1.21 mol) was transferred to reactor 1 using acetone (41.6 vol, 80 vol, ACS) to facilitate the transfer. The batch was heated to 50±5° C. over 33 minutes with dissolution occurring at 30° C. The batch was clarified into a second reactor via a transfer pump fitted with an inline filter (Pall P/N 12077, 10 micron) and reheated from 46° C. to 50±5° C. Methanesulfonic acid (121.4 g, 1.05 equiv, 99% extra pure) was added to the pale yellow batch over 12 minutes and the heating then discontinued. After fourteen minutes, white solids were observed, which increased in number to give after 59 minutes a white suspension. The batch was in the range of 25±5° C. after 7 hours 51 minutes and aged for a further 19 hours 21 minutes (10 hours 30 minutes at ≦27° C.). The batch was filtered under suction via a 24-inch polypropylene filter (PTFE cloth) and the reactor rinsed with acetone (2.0 L, clarified, ACS) and the rinse transferred to the cake. The cake was covered with a stainless steel cover and sucked dry under a flow of nitrogen. The total filtration time was 21 minutes. The batch (net wet weight 764 g) was transferred to three glass drying trays and dried in a vacuum oven to constant weight at 25±5° C. over 21 hours 54 minutes (565 g, 89% of theory). A sample was removed for analysis and the batch maintained in vacuo at 25±5° C. The batch was then transferred to two 80-oz amber glass bottles (Teflon lined polypropylene closure), blanketed with argon and stored at −10 to −20° C.

Provenance & Evidence