反应详情

4,5-Dihydroxy-pyridine-2-carboxylic acid (844 mg, 5.45 mmol) was dissolved in ethanol (20 mL). Gaseous hydrochloric acid was bubbled through the mixture for 5 minutes whilst it was cooled in an ice bath. The solution was then heated to reflux for 2 hours. This procedure was repeated a further two times and then the mixture heated for 24 hours. The volatiles were removed in vacuo and water added (5 mL). This was also removed under reduced pressure. The hydrochloride salt of the desired product was produced in this way and used without further purification.

1. customGaseous hydrochloric acid was bubbled through the mixture for 5 minutes whilst it
2. temperaturewas cooled in an ice bath
3. temperatureThe solution was then heated
4. temperatureto reflux for 2 hours
5. temperaturethe mixture heated for 24 hours
6. customThe volatiles were removed in vacuo and water
7. additionadded (5 mL)
8. customThis was also removed under reduced pressure