反应详情

温度

110 °C

To acetic anhydride (60 mL, 0.635 mol) at 110° C. under a nitrogen atmosphere was added 2-methyl-4-nitro-pyridin-1-ol (15)(17.1 g, 111 mmol) portionwise over 1 minute. After approximately 2 minutes the solution began to darken and heating maintained at 100-120° C. for 30 minutes and then allowed to cool to 80° C. Ethanol (60 mL) was added and the solution was concentrated under vacuum; residue slurried in water (140 mL) and the mixture neutralised with NaHCO3 (ca. 40 g). The aqueous liquor was extracted with ethyl acetate (4×100 mL, combined extracts washed with brine (2×100 mL, dried over Na2SO4, concentrated in vacuo to a crude oil. The material was subjected to flash chromatography eluent hexane:TBME (2:1). A brown oil was isolated, single peak in LC-MS analysis, (6.44 g 30%); m/z (LC-MS, ESP), RT=3.65 mins, (M+H) 197.

1. temperatureheating
2. temperatureto cool to 80° C
3. concentrationthe solution was concentrated under vacuum
4. extractionThe aqueous liquor was extracted with ethyl acetate (4×100 mL
5. washcombined extracts washed with brine (2×100 mL
6. dry with materialdried over Na2SO4
7. concentrationconcentrated in vacuo to a crude oil
8. customA brown oil was isolated