p-Toluenesulfonic acid monohydrate → 3,4-difluoro-2-(2-fluoro-4-iodo-phenylamino)-5-formyl-N-(2-hydroxy-ethoxy)-benzamide

Participants

Reaction Steps

N-[2-(Tert-butyldimethylsilanyloxy)-ethoxy]-3,4-difluoro-2-(2-fluoro-4-iodophenylamino)-5-formyl-benzamide (37.1 g as a crude product containing the desilylated product) prepared in Step E was dissolved in a mixed solvent of tetrahydrofuran (200 ml) and water (16 ml). To this solution, p-toluenesulfonic acid monohydrate (1.76 g, 9.25 mmol) was added, and the mixture was stirred at room temperature for 12 hours. The reaction mixture was extracted with ethyl acetate, and the organic layer was washed with saturated brine, dried over magnesium sulfate, and evaporated under reduced pressure. The resultant residue was triturated with ethyl acetate to give 3,4-difluoro-2-(2-fluoro-4-iodo-phenylamino)-5-formyl-N-(2-hydroxy-ethoxy)-benzamide (16.0 g, 72% yield in two steps) as a yellow solid.

Provenance & Evidence