반응 #93186

반응 방정식

6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-bromo-4-hydroxy-2H-benzo[b]pyran

sodium hydride

2-Pyrrolidone

sodium hydride

6-cyano-3,4-dihydro-2,2-dimethyl-3,4-epoxy-2H-benzo[b]pyran

→

title compound

수율 60.0%

6-Cyano-3,4-dihydro-2,2-dimethyl-trans-4-(2-oxo-1-pyrrolidinyl)-2H-benzo[b]pyran-3-ol

수율 60.0%

용매

Water

dimethylsulphoxide

반응 조건

후처리

1. 1
   기타resulted
2. 2
   기타crystallisation of the product after which it
3. 3
   온도was cooled in ice
4. 4
   여과filtered under suction
5. 5
   기타Crystallisation from ethanol (20 ml)

실험 절차

A solution of 6-cyano-3,4-dihydro-2,2-dimethyl-trans-3-bromo-4-hydroxy-2H-benzo[b]pyran (4 g, 14.2 mM) in dimethylsulphoxide (20 ml) was stirred and sodium hydride (60% dispersion in oil, 0.6 g, 15 mM) added. The suspension was stirred for 1 hour when a solution of 6-cyano-3,4-dihydro-2,2-dimethyl-3,4-epoxy-2H-benzo[b]pyran resulted. 2-Pyrrolidone (1.8 g, 21 mM) and further sodium hydride (0.8 g, 21 mM) were introduced and the mixture stirred at room temperature for an additional 16 hours. Water (40 ml) was slowly added to the mixture to induce crystallisation of the product after which it was cooled in ice and filtered under suction. Crystallisation from ethanol (20 ml) gave the title compound as a cream coloured solid in 60% yield. Recrystallisation from ethyl acetate afforded the pure product as needles, m.p. 226.5°-227.5° having an nmr spectrum and t.l.c. characteristics identical to those of the compound of Description 6.

출처