反应详情

温度

80 °C

19 g of 4,5-dimethoxy-2-methylpyridine 1-oxide are metered into 60 ml of acetic anhydride, warmed to 80° C., in the course of 30 minutes in a manner such that the temperature does not rise above 100° C. After a further 45 minutes at 85° C., excess acetic anhydride is distilled off in vacuo and the oily dark residue, which essentially consists of the intermediate 2-acetoxymethyl-4,5-dimethoxypyridine is stirred with 80 ml of 2N sodium hydroxide solution at 80° C. for 1 hour. After dilution with 80 ml of water and cooling, the mixture is extracted eight times with 100 ml of methylene chloride each time, the combined organic phases are washed twice with 1N sodium hydroxide solution, dried and concentrated and the crystalline, brownish residue is recrystallized from toluene. 14 g (74% of theory) of 2-hydroxymethyl-4,5-dimethoxy-pyridine of m.p. 122°-124° C. are obtained.

1. customdoes not rise above 100° C
2. distillationexcess acetic anhydride is distilled off in vacuo
3. temperatureAfter dilution with 80 ml of water and cooling
4. extractionthe mixture is extracted eight times with 100 ml of methylene chloride each time
5. washthe combined organic phases are washed twice with 1N sodium hydroxide solution
6. customdried
7. concentrationconcentrated
8. customthe crystalline, brownish residue is recrystallized from toluene