反应详情

3-Bromo-2,4-dimethylpyridine-N-oxide (14.7 g) in warm acetic anhydride (150 ml) was added dropwise to acetic anhydride (500 ml) at 125° and the mixture was refluxed for 1/2 hour, allowed to cool and then poured into water/ethanol (4:1, 500 ml). The solution was acidified with dilute hydrochloric acid and evaporated to dryness. The residue was refluxed with 2 N hydrochloric acid (100 ml) for 1 hour, cooled and extracted with chloroform. The aqueous phase was adjusted to pH 12 with sodium hydroxide and was extracted with chloroform, and this chloroform extract was evaporated to a residue which was crystallised from n-hexane to give 3-bromo-2-hydroxymethyl-4-methylpyridine (5.8 g) m.p. 75°-77°.

1. temperaturethe mixture was refluxed for 1/2 hour
2. temperatureto cool
3. customevaporated to dryness
4. temperatureThe residue was refluxed with 2 N hydrochloric acid (100 ml) for 1 hour
5. temperaturecooled
6. extractionextracted with chloroform
7. extractionwas extracted with chloroform
8. extractionthis chloroform extract
9. customwas evaporated to a residue which
10. customwas crystallised from n-hexane