反应详情

A solution of 30.06 g (0.18 mole) of 2,3,5-trimethyl-4-methoxypyridine N-oxide in 100 ml of methylene chloride was added slowly (over approximately one hour) over a solution of 0.38 g of dimethylaminopyridine in 53.4 ml (0.565 mole) of acetic anhydride, heated to 90°-95° C., with the temperature being held within the abovementioned range and the methylene chloride being removed by distillation. At the end of the addition, the distillation was continued for a further 10 minutes, the mixture was cooled to below 90° C. and 7.5 ml of water were added slowly, holding the temperature below 90° C. Crude 2-acetoxymethyl-3,5-dimethyl-4-methoxypyridine was obtained by distillation at reduced pressure and was used directly as starting product for the hydrolysis (Example 2).

1. temperatureheated to 90°-95° C., with the temperature
2. customthe methylene chloride being removed by distillation
3. additionAt the end of the addition
4. distillationthe distillation
5. temperaturethe mixture was cooled to below 90° C.
6. addition7.5 ml of water were added slowly
7. customthe temperature below 90° C