Water → 3-Benzyl-7-(4-tert-butoxycarbonyl-piperazin-1-yl)-indole-1,2-dicarboxylic acid 2-benzyl ester 1-tert-butyl ester

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Reaction Conditions

Reaction Steps

A solution of 3-benzyl-7-(4-tert-butoxycarbonyl-piperazin-1-yl)-indole-1-carboxylic acid tert-butyl ester (200 mg, 0.41 mmol) in THF (10 ml) was cooled to −78° C., and t-BuLi (1 ml, 1.7 M in pentane) was added. After stirring at −78° C. for 20 minutes, 0.15 ml of benzyl chloroformate was added and the reaction was allowed to warm up to room temperature for 30 minutes. Water was slowly added, followed by EtOAc. The organic layer was separated and washed with water and brine. After drying over MgSO4, the organic fraction was concentrated in vacuo and the resulting residue was purified by flash chromatography to give 3-benzyl-7-(4-tert-butoxycarbonyl-piperazin-1-yl)-indole-1,2-dicarboxylic acid 2-benzyl ester 1-tert-butyl ester as a yellow solid (100 mg, 39%). MS: (M+H)+ 626.4.

Provenance & Evidence