تفاعل #1833211

معادلة التفاعل

2,6-dichloro-5-methoxy pyrimidine

vinyl magnesium bromide

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

→

title compound

المردود 60.0%

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

المردود 60.0%

المذيبات

tetrahydrofuran

tetrahydrofuran

ظروف التفاعل

المعالجة

1. 1
   أخرىExcess Grignard reagent was quenched by addition of acetone (200 milliliters (mL)) while the temperature of the mixture
2. 2
   درجة الحرارةwas maintained at a temperature below 20° C
3. 3
   workup.STIRRINGstirred overnight
4. 4
   أخرىA yellow solid precipitated out
5. 5
   ترشيحThe solid was filtered
6. 6
   غسيلwashed with ethyl acetate (500 mL)
7. 7
   تركيزThe filtrate was concentrated under reduced pressure
8. 8
   workup.ADDITIONthe resulting crude compound was diluted with ethyl acetate (2 liters (L))
9. 9
   أخرىThe resulting undissolved, dark, semi-solid was separated by filtration
10. 10
    تركيزIt was further concentrated under reduced pressure
11. 11
    أخرىto provide a crude compound, which
12. 12
    أخرىwas purified by column chromatography
13. 13
    غسيلThe compound was eluted with 5% to 10% ethyl acetate in hexane mixture

الإجراء التجريبي

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).

المصدر