反应详情

Sodium sulphite (130 g, 1.034 mol) was added slowly to a solution of 3-chlorosulfonyl-4-fluoro-benzoic acid (49.39 g, 0.207 mol) in water (150 ml) at 0° C. with a vigorous stirring. After the addition was completed the reaction was warmed back to room temperature for 1 hour and the pH of the solution was kept around pH 6–7 with 2N sodium hydroxide solution. The white milky suspension was filtered and the solid washed with 2N sodium hydroxide solution (150 ml) and then water (100 ml). The filtrate was then cooled in an ice bath and concentrated HCl was added until no more precipitate was formed (pH<1). The white precipitate was then filtered, pressed dry and left in a dessicator overnight under vacuum and over activated silica (27.92 g, 66%). m/z (LC-MS, ESP), RT=0.98 min, (M−−1)=203

1. additionAfter the addition
2. filtrationThe white milky suspension was filtered
3. washthe solid washed with 2N sodium hydroxide solution (150 ml)
4. temperatureThe filtrate was then cooled in an ice bath
5. additionconcentrated HCl was added until no more precipitate
6. customwas formed (pH<1)
7. filtrationThe white precipitate was then filtered
8. custompressed dry