反应 #56746

反应方程式

1-[(3S)-5-hydroxy-3-(hydroxymethyl)-2,3-dihydro-1,4-benzodioxin-6-yl]-1-ethanone oxime

N,N-dimethylacetamide acetonitrile

phosphorus oxychloride

N,N-dimethylacetamide acetonitrile

sodium acetate

→

[2-Methyl-7,8-dihydro[1,4]dioxino[2,3-g][1,3]benzoxazol-8-yl]methanol

反应条件

后处理

1. 1
   温度The solution was cooled in an ice/water bath
2. 2
   萃取extracted with ethyl acetate
3. 3
   干燥dried over magnesium sulfate
4. 4
   过滤filtered
5. 5
   其他evaporated in vacuum
6. 6
   其他chromatographed on silica gel with 60% hexane/ethyl acetate
7. 7
   其他to remove impurities
8. 8
   洗涤the product eluted with 40% hexane/ethyl acetate
9. 9
   其他After evaporation of the solvent in vacuum, 2.08 g (75%) of the (S)-enantiomer of the title compound
10. 10
    其他was obtained as a white solid, m.p. 120° C

实验过程

3.03 g (12.6 mmole) of 1-[(3S)-5-hydroxy-3-(hydroxymethyl)-2,3-dihydro-1,4-benzodioxin-6-yl]-1-ethanone oxime was dissolved in- a mixture of 1:3 N,N-dimethylacetamide/acetonitrile (100 mL). The solution was cooled in an ice/water bath and a solution of phosphorus oxychloride (1.26 mL, 35 mmole) in 1:3 N,N-dimethylacetamide/acetonitrile (30 mL) was added. The reaction mixture was stirred under nitrogen over a period of 48 hours. It was then added to an ice cold, saturated solution of sodium acetate, extracted with ethyl acetate, dried over magnesium sulfate, filtered and evaporated in vacuum. The resulting crude oil was column chromatographed on silica gel with 60% hexane/ethyl acetate to remove impurities and the product eluted with 40% hexane/ethyl acetate. After evaporation of the solvent in vacuum, 2.08 g (75%) of the (S)-enantiomer of the title compound was obtained as a white solid, m.p. 120° C. MS (ESI) m/z 222 (M+H)+.

来源