反应详情

419 g (1.6 mole) of 2,3-dimethoxy-5-sulphamoyl benzoic acid and 1,351 g (11.35 moles) of thionyl chloride are placed in a 2 liter flask fitted with an agitator, a thermometer and a condenser connected to a soda bubbler. The mixture is brought to reflux for 1 hour, after which the excess thionyl chloride is expelled under vacuum. The residue is dissolved in 1,000 ml of hexane, filtered, washed twice with 500 ml of petroleum ether and dried in a desiccator under vacuum. 424 g (yield 94.8%) of 2,3-dimethoxy-5-sulphamoyl benzoyl chloride is obtained, with a melting point of 153° C.

1. customfitted with an agitator
2. temperatureto reflux for 1 hour
3. filtrationfiltered
4. washwashed twice with 500 ml of petroleum ether
5. customdried in a desiccator under vacuum