Water → (E)-3-[1-(4-bromomethyl-benzenesulfonyl)-1H-pyrrol-3-yl]-acrylic acid tert-butyl ester

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Reaction Steps

4.25 g of sodium hydride (60% strength) are suspended in 300 ml of THF under nitrogen at −30° C. 9.78 g of (E)-3-(1H-pyrrol-3-yl)-acrylic acid tert-butyl ester (compound D1) are added to the suspension and warmed slowly to room temperature during 55 min. Afterwards it is recooled to −30° C. and it is added 13.98 g of 4-(bromomethyl)-benzenesulphonylchloride and stirred for 45 min. Then it is warmed to room temperature and stirred for 2 hour. After cooling to 0-5° C. water is added. Then the mixture is extracted with ethyl acetate and the organic phase is dried over sodium sulfate. The organic phase is evaporated under vacuum. The crude product is purified by silica gel flash chromatography using a gradient of hexane and ethyl acetate from 9:1-7:1.

Provenance & Evidence