反应详情

A solution of 1 g of 3-hydroxybenzaldehyde dimethyl acetal and 2 g of potassium tert.butoxide in 10 ml of anhydrous dimethylformamide was heated at 60° C. under an atmosphere of dry nitrogen for 1 hour. The mixture was then cooled to room temperature and 900 mg of 4-chloropyridinium hydrochloride were added portionwise over a period of 20 minutes. The mixture was then heated at 160° C. for 18 hours, cooled, 100 ml of water were added and the product was extracted with ethyl acetate. The combined extracts were washed with 1M aqueous sodium hydroxide solution and with brine, and then dried over anhydrous magnesium sulphate. Evaporation to dryness left a brown oil which was purified by column chromatography on silica gel using hexane/ethyl acetate (gradient: 90:10 to 20:80) for the elution to give 3-(4-pyridyloxy)-benzaldehyde dimethyl acetal as a light brown oil.

1. temperatureThe mixture was then heated at 160° C. for 18 hours
2. temperaturecooled
3. extractionthe product was extracted with ethyl acetate
4. washThe combined extracts were washed with 1M aqueous sodium hydroxide solution and with brine
5. dry with materialdried over anhydrous magnesium sulphate
6. customEvaporation to dryness
7. waitleft a brown oil which
8. customwas purified by column chromatography on silica gel
9. washfor the elution