Reaktion #1833211

Reaktionsgleichung

2,6-dichloro-5-methoxy pyrimidine

vinyl magnesium bromide

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

→

title compound

Ausbeute 60.0%

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

Ausbeute 60.0%

Lösungsmittel

tetrahydrofuran

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeExcess Grignard reagent was quenched by addition of acetone (200 milliliters (mL)) while the temperature of the mixture
2. 2
   Temperaturwas maintained at a temperature below 20° C
3. 3
   workup.STIRRINGstirred overnight
4. 4
   SonstigeA yellow solid precipitated out
5. 5
   FiltrationThe solid was filtered
6. 6
   Waschenwashed with ethyl acetate (500 mL)
7. 7
   EinengenThe filtrate was concentrated under reduced pressure
8. 8
   workup.ADDITIONthe resulting crude compound was diluted with ethyl acetate (2 liters (L))
9. 9
   SonstigeThe resulting undissolved, dark, semi-solid was separated by filtration
10. 10
    EinengenIt was further concentrated under reduced pressure
11. 11
    Sonstigeto provide a crude compound, which
12. 12
    Sonstigewas purified by column chromatography
13. 13
    WaschenThe compound was eluted with 5% to 10% ethyl acetate in hexane mixture

Vorschrift

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).

Quelle