반응 #1833211

반응 방정식

2,6-dichloro-5-methoxy pyrimidine

vinyl magnesium bromide

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

→

title compound

수율 60.0%

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

수율 60.0%

용매

tetrahydrofuran

tetrahydrofuran

반응 조건

후처리

1. 1
   기타Excess Grignard reagent was quenched by addition of acetone (200 milliliters (mL)) while the temperature of the mixture
2. 2
   온도was maintained at a temperature below 20° C
3. 3
   workup.STIRRINGstirred overnight
4. 4
   기타A yellow solid precipitated out
5. 5
   여과The solid was filtered
6. 6
   세척washed with ethyl acetate (500 mL)
7. 7
   농축The filtrate was concentrated under reduced pressure
8. 8
   workup.ADDITIONthe resulting crude compound was diluted with ethyl acetate (2 liters (L))
9. 9
   기타The resulting undissolved, dark, semi-solid was separated by filtration
10. 10
    농축It was further concentrated under reduced pressure
11. 11
    기타to provide a crude compound, which
12. 12
    기타was purified by column chromatography
13. 13
    세척The compound was eluted with 5% to 10% ethyl acetate in hexane mixture

실험 절차

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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