反应详情

To a solution of 2-formyl-pyrrole-1-carboxylic acid tert-butyl ester (23.4 g, 120 mmol) (prepared as described below) in dry THF (275 mL) was added ethylmagnesium chloride (Aldrich, 0.5 M solution in THF, 480 mL, 240 mmol) dropwise at −65° C. and the reaction mixture was stirred at the same temperature for 0.5 hour. The cooling bath was then removed and the reaction mixture was stirred for another 1 hour to give a clear solution. The reaction was quenched by slowly adding EtOH (60 mL) and a saturated aqueous solution of NH4Cl (200 mL) at 5° C., and extracted with ethyl acetate (3×250 mL). The combined organic extracts were successively washed with water (200 mL) and brine (200 mL), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. Flash chromatography (Biotage, 75-S, 92/8 hexanes/ethyl acetate) purification of the crude oil afforded 2-(1-hydroxy-prop-2-ynyl)-pyrrole-1-carboxylic acid tert-butyl ester as a light amber oil. (Yield 25.0 g, 94.2%).

1. customThe cooling bath was then removed
2. stirringthe reaction mixture was stirred for another 1 hour
3. customto give a clear solution
4. customThe reaction was quenched by slowly adding EtOH (60 mL)
5. extractiona saturated aqueous solution of NH4Cl (200 mL) at 5° C., and extracted with ethyl acetate (3×250 mL)
6. washThe combined organic extracts were successively washed with water (200 mL) and brine (200 mL)
7. dry with materialdried over anhydrous sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated in vacuo
10. customFlash chromatography (Biotage, 75-S, 92/8 hexanes/ethyl acetate) purification of the crude oil