Ethyl Acetate → 3-(1-Benzenesulfonyl-4-bromo-1H-indol-2-yl)-but-2-enoic acid methyl ester

Participants

Reaction Steps

Methyldiethylphosphonoacetate (366 mg, 0.97 mmol) was dissolved in DMF (8 mL) under nitrogen, cooled in an ice bath, and treated with potassium t-butoxide (434 mg, 3.87 mmol). The ice bath was removed and allowed to warm to room temperature over 30 min. 1-(1-Benzenesulfonyl-4-bromo-1H-indol-2-yl)ethanone (366 mg, 0.97 mmol) dissolved in DMF (4 mL) was added and the reaction heated at 50° C. for 1.5 h. The reaction was allowed to cool and poured into ethyl acetate/saturated ammonium chloride solution. The aqueous was washed with more ethyl acetate. Then the pH was lowered and the aqueous washed a third time with ethyl acetate. The organic portions were washed with brine, dried (MgSO4), filtered and evaporated to give 3.24 g brown oil. The material was purified by column chromatography using (5:1) hexane:ethyl acetate to give 207 mg (28%) of a crude foam. The material was used without further purification. MS [EI+] 434, 436 (M+H)+.

Provenance & Evidence