반응 #62748

반응 방정식

acetic acid

bromocresol green

sodium cyanoborohydride

acetic acid

acetic acid

ethyl 2-cyano-3-(7,8-dimethoxy-2H-1-benzopyran-5-yl)propenoate

→

Ethyl 2-cyano-3-(7,8-dimethoxy-2H-1-benzopyran-5-yl)propanoate

용매

ethanol

ethanol

반응 조건

후처리

1. 1
   온도Heating
2. 2
   기타the ethanol removed under reduced pressure
3. 3
   추출successively extracted with water (125 mL), saturated sodium bicarbonate (3×100 mL) and water (100 mL)
4. 4
   건조dried over magnesium sulfate
5. 5
   기타The volatiles were removed under reduced pressure
6. 6
   기타to leave an amber oil, 18.22 g (91.4%) which
7. 7
   기타was used without further purification

실험 절차

A mixture of ethyl 2-cyano-3-(7,8-dimethoxy-2H-1-benzopyran-5-yl)propenoate (19.8 g, 0.63 mole) in ethanol (500 mL) under nitrogen was treated with acetic acid (4 mL) and a trace of bromocresol green and heated to reflux. Heating was discontinued and sodium cyanoborohydride (4.4 g, 0.07 mole) in ethanol (100 mL) was co-added with additional acetic acid (11 mL). The mixture was stirred under nitrogen for 2 hr, acetic acid (10 mL) added and the ethanol removed under reduced pressure. The resultant yellow solid was taken up in ethyl acetate (250 mL) and successively extracted with water (125 mL), saturated sodium bicarbonate (3×100 mL) and water (100 mL), then dried over magnesium sulfate. The volatiles were removed under reduced pressure to leave an amber oil, 18.22 g (91.4%) which was used without further purification.

출처