反应 #1833211

反应方程式

2,6-dichloro-5-methoxy pyrimidine

vinyl magnesium bromide

2,3-dichloro-5,6-dicyano-p-benzoquinone

→

title compound

收率 60.0%

2,6-Dichloro-5-methoxy-4-vinyl pyrimidine

收率 60.0%

溶剂

tetrahydrofuran

tetrahydrofuran

反应条件

后处理

1. 1
   其他Excess Grignard reagent was quenched by addition of acetone (200 milliliters (mL)) while the temperature of the mixture
2. 2
   温度was maintained at a temperature below 20° C
3. 3
   workup.STIRRINGstirred overnight
4. 4
   其他A yellow solid precipitated out
5. 5
   过滤The solid was filtered
6. 6
   洗涤washed with ethyl acetate (500 mL)
7. 7
   浓缩The filtrate was concentrated under reduced pressure
8. 8
   workup.ADDITIONthe resulting crude compound was diluted with ethyl acetate (2 liters (L))
9. 9
   其他The resulting undissolved, dark, semi-solid was separated by filtration
10. 10
    浓缩It was further concentrated under reduced pressure
11. 11
    其他to provide a crude compound, which
12. 12
    其他was purified by column chromatography
13. 13
    洗涤The compound was eluted with 5% to 10% ethyl acetate in hexane mixture

实验过程

To a solution of commercially available 2,6-dichloro-5-methoxy pyrimidine (100 grams (g), 0.55 moles (mol)) in dry tetrahydrofuran was added, dropwise, 1 molar (M) vinyl magnesium bromide in tetrahydrofuran solvent (124 g, 0.94 mol) over one hour (h) at room temperature. The mixture was then stirred for 4 h at room temperature. Excess Grignard reagent was quenched by addition of acetone (200 milliliters (mL)) while the temperature of the mixture was maintained at a temperature below 20° C. Thereafter, 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ; 151 g, 0.67 mol) was added at once and stirred overnight. A yellow solid precipitated out. The solid was filtered and washed with ethyl acetate (500 mL). The filtrate was concentrated under reduced pressure and the resulting crude compound was diluted with ethyl acetate (2 liters (L)). The resulting undissolved, dark, semi-solid was separated by filtration using ethyl acetate. It was further concentrated under reduced pressure to provide a crude compound, which was purified by column chromatography. The compound was eluted with 5% to 10% ethyl acetate in hexane mixture to provide the title compound (70 g, 60%): mp 60-61° C.; 1H NMR (CDCl3) δ 3.99 (s, 3H), 5.85 (d, 1H), 6.75 (d, 1H), 6.95 (dd, 1H).

来源