反应详情

Sodium borohydride (0.59 g, 15.6 mmol, 8 equiv) was added portionwise to a solution of 5-(chlorosulfonyl)-2,4-difluorobenzoic acid 885-6a (0.5 g, 1.9 mmol, 1 equiv) in 10 mL THF at 0° C. The reaction was stirred at this temperature for 1 h and then concentrated down and the residue acidified to pH 2 with 5N HCl. The precipitate was removed by filtration and the liquid concentrated down to provide 2,4-difluoro-5-sulfobenzoic acid 885-6b as a white solid (433 mg, 100% yield)

1. concentrationconcentrated down
2. customThe precipitate was removed by filtration
3. concentrationthe liquid concentrated down