反応 #93186

反応方程式

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

収率 60.0%

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

収率 60.0%

溶媒

Water

dimethylsulphoxide

反応条件

後処理

1. 1
   その他resulted
2. 2
   その他crystallisation of the product after which it
3. 3
   温度was cooled in ice
4. 4
   ろ過filtered under suction
5. 5
   その他Crystallisation from ethanol (20 ml)

実験手順

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.

出典