tert-Butyl bromoacetate → N-[2-(1,1-Dimethylethoxy)-2-oxoethyl]-L-tryptophan 1,1-dimethylethyl ester

Participants

Reaction Steps

To a solution of L-tryptophan 1,1-dimethylethyl ester (17.10 g; 65.68 mmol) in CH3CN (150 mL) 2M phosphate. buffer (pH 8; 150 mL) was added. Tert-butyl bromoacetate (10.7 mL; 72.25 mmol) was dropped into the mixture and vigorous mechanical stirring set on. The reaction was monitored by HPLC (Chromatographic method of Example 3, A)). After 23 h the organic layer was separated and concentrated to dryness to give a crude oil (26.62 g), which was purified by flash chromatography (silica gel; n-hexane/ethyl acetate, 8:2 v/v) to give the desired product (20.07 g; 53.59 mmol). Yield 54.5% starting from L-tryptophan.

Provenance & Evidence