Trifluoroacetic anhydride → p-Toluenesulfonic acid

Participants

Reaction Steps

To a solution of N-(1-(1-cyclopropyl-1-oxopropan-2-yl)-5-iodopyridin-2(1H)-ylidene)-4-methylbenzene sulfonamide (30.5 g) in THF (300 ml) was added trifluoroacetic anhydride (18.3 ml) dropwise. After 3 h, the resulting precipitate was collected by filtration, and washed with ether to give p-toluenesulfonic acid salt of the title compound as a white solid. The solid obtained was dissolved in a mixture of 1 M NaOH, EtOAc and THF. Then the organic layer was washed with brine, dried over MgSO4 and concentrated. The resulting solid was triturated with IPE, and collected to give the title compound (17.7 g) as a pale yellow solid.

Provenance & Evidence