반응 #64204

반응 방정식

cyclopentanone

sodium hydride

5-bromomethylthiophene-2-carbonitrile

triethyl phosphite

→

5-cyclopentylidenemethylthiophene-2-carbonitrile

용매

tetrahydrofuran

tetrahydrofuran

반응 조건

후처리

1. 1
   기타Then triethyl phosphite is removed at 40°-60°/0.06 mbar
2. 2
   workup.DISTILLATIONthe residue is distilled on a bulb tube at 130°-150°/0.004 mbar
3. 3
   기타resulting in 24 g of (5-cyano-2-thienyl)methylphosphonic acid diethyl ester
4. 4
   workup.ADDITIONthe mixture is poured on water
5. 5
   추출extracted with ethyl acetate
6. 6
   건조The ethyl acetate phase is dried
7. 7
   기타evaporated
8. 8
   기타the residue is recrystallized from isopropanol

실험 절차

In a second process, 20 g of 5-bromomethylthiophene-2-carbonitrile is heated with 200 ml of triethyl phosphite for 4 hours to 150°. Then triethyl phosphite is removed at 40°-60°/0.06 mbar, and the residue is distilled on a bulb tube at 130°-150°/0.004 mbar, resulting in 24 g of (5-cyano-2-thienyl)methylphosphonic acid diethyl ester. Of this product, 5 g is added dropwise, with 1.5 ml of cyclopentanone in 5 ml of tetrahydrofuran, to a suspension of 581 mg of sodium hydride/oil (80% strength) and 116 mg of 15-crown-5 in 5 ml of tetrahydrofuran. After 2 hours of agitation at room temperature, the mixture is poured on water and extracted with ethyl acetate. The ethyl acetate phase is dried and evaporated, and the residue is recrystallized from isopropanol, thus obtaining 3.0 g of 5-cyclopentylidenemethylthiophene-2-carbonitrile, identical to the product described above.

출처