反応 #1833211

反応方程式

2,6-dichloro-5-methoxy pyrimidine

vinyl magnesium bromide

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

→

title compound

収率 60.0%

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

収率 60.0%

溶媒

tetrahydrofuran

tetrahydrofuran

反応条件

後処理

1. 1
   その他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
   その他A yellow solid precipitated out
5. 5
   ろ過The solid was filtered
6. 6
   洗浄washed with ethyl acetate (500 mL)
7. 7
   濃縮The filtrate was concentrated under reduced pressure
8. 8
   workup.ADDITIONthe resulting crude compound was diluted with ethyl acetate (2 liters (L))
9. 9
   その他The resulting undissolved, dark, semi-solid was separated by filtration
10. 10
    濃縮It was further concentrated under reduced pressure
11. 11
    その他to provide a crude compound, which
12. 12
    その他was purified by column chromatography
13. 13
    洗浄The compound was eluted with 5% to 10% ethyl acetate in hexane mixture

実験手順

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).

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