Tetrahydrofuran → (E)-3-[1-(3-Bromo-benzenesulfonyl)-1H-pyrrol-3-yl]-acrylic acid tert-butyl ester

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Reaction Conditions

Reaction Steps

A mixture of 0.77 g NaH (60%) with 65.0 ml THF is cooled to −30° C. Then 3.2 g 3.1 g (E)-3-(1H-pyrrol-3-yl)-acrylic acid tert-butyl ester are added. During the addition there is liberated a gas. The solution is stirred at ambient temperature for 0.5 h. Finally 5.0 g 3-bromobenzenesulfonylchloride are added at −30° C. The suspension is stirred at ambient temperature for 24 h. The suspension is treated with water and the solution is extracted with ethyl acetate. The organic layer is dried over sodium sulfate and evaporated. The residue (oil) is crystallized from methanol. The crystals are dried in vacuo. By this method 5.7 g of colorless crystals are obtained.

Provenance & Evidence