反应详情

Into 0.82 g (3.8 mmol) of sodium 2-chloropyridine-6-sulfonate prepared in accordance with Example 1, 10 ml of concentrated hydrochloric acid was added, and the mixture was stirred at room temperature overnight. Then, the solvent was distilled off, and after an addition of 200 ml of 2-propanol, the residue was heated. Insoluble matters were removed by filtration, and the filtrate was distilled under reduced pressure to obtain 710 mg (96.6%) of 2-chloropyridine-6-sulfonic acid as crystalline solid. Purification was conducted by recrystallization from 2-propanol.

1. additionwas added
2. distillationThen, the solvent was distilled off
3. additionafter an addition of 200 ml of 2-propanol
4. temperaturethe residue was heated
5. customInsoluble matters were removed by filtration
6. distillationthe filtrate was distilled under reduced pressure