(R)-camphorsulfonic acid → Isavuconazole

Participants

Reaction Steps

To a solution of racemic 3-[4-(4-cyanophenyl)thiazol-2-yl]-1-(1H-1,2,4-triazol-1-yl)-2-(2,5-difluorophenyl)-butan-2-ol (100 g) in acetone (1000 ml) a solution of (1R)-10-camphorsulfonic acid (47 g) in methanol (500 ml) was added at rt, then slurry was heated under stirring to almost reflux for ca. 30 min, then cooled slowly to rt, seeded with the pure enantiomeric salt and stirred over night. The solid was collected by filtration, washed with methanol/acetone mixture, dried under reduced pressure. The residue was taken up with a solvent mixture of methylenechloride/water and after addition of saturated aqueous sodium bicarbonate solution the organic phase was separated and aqueous phase washed twice with methylenechloride. The combined organic phases were filtrated, the solvent removed under reduced pressure. Recrystallization of the crude product from aqueous ethanol provided enantiomerically pure title compound: 39 g (39% yield, 92% ee). The analytical data were identical with published: U.S. Pat. No. 6,300,353 and WO 99/45008.

Provenance & Evidence