反应详情

Isobutyl 2-hydroxy-5-[2-(4-sulfophenyl)ethenyl]benzoate dipotassium salt (37.2 g, 0.09 mol) was added to a boiling solution of acetic acid (20 ml) and acetic anhydride (80 ml). Sulfuric acid (8 ml) was added cautiously and the mixture refluxed until the major part of the solids had dissolved, and then more acetic anhydride (80 ml) was added. After boiling for 1 h, the mixture was cooled to room temperature. Diethyl ether (350 ml) was added and the suspension filtered and washed with diethyl ether. Yield 36.1 g (88%)

1. temperaturethe mixture refluxed until the major part of the solids
2. dissolutionhad dissolved
3. filtrationthe suspension filtered
4. washwashed with diethyl ether