反应详情

A solution of 2-(benzo[1,2,5]thiadiazole-4-sulfonylamino)-4-methylbenzoic acid methyl ester (1.22 g, 3.36 mmol) in 3:1 THF/water (10 mL) was treated with LiOH.H2O (1.41 g, 33.6 mmol) and was stirred at rt for 16 h. The mixture was acidified with 1 N HCl, and the resulting precipitate was collected by filtration, washing with water. Drying in air provided the title acid as a tan solid (0.89 g, 2.5 mmol, 74%). 1H NMR (500 MHz, CDCl3): 11.16 (s, 1H), 8.38 (dd, J=7.0, 1.0, 1H), 8.22 (dd, J=8.8, 1.0, 1H), 7.84 (d, J=8.1, 1H), 7.71 (dd, J=8.8, 7.1, 1H), 7.56 (br s, 1H), 6.83 (br d, J=8.4, 1H), 2.32 (s, 3H).

1. filtrationthe resulting precipitate was collected by filtration
2. washwashing with water
3. customDrying in air