Trifluoroacetic acid → Trifluoroacetic acid

Participants

Reaction Steps

To a solution of 3-benzyl-7-(4-tert-butoxycarbonyl-piperazin-1-yl)-2-methylsulfanyl-indole-1-carboxylic acid tert-butyl ester (277 mg) in CH2Cl2 (10 ml) was added MCPBA (296 mg) at 0° C. The reaction was allowed to warm up to room temperature overnight. After adding 150 mg of PPh3, the reaction was stirred for another 30 minutes and was then poured into a mixture of EtOAc/H2O. 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)-2-methanesulfonyl-indole-1-carboxylic acid tert-butyl ester as yellow solid. MS: (M+H)+ 570.4. 3-Benzyl-7-(4-tert-butoxycarbonyl-piperazin-1-yl)-2-methanesulfonyl-indole-1-carboxylic acid tert-butyl ester was then dissolved in dichloromethane and treated with trifluoroacetic acid to give 3-benzyl-2-methanesulfonyl-7-piperazin-1-yl-1H-indole as a TFA salt, MS: (M+H)+ 370.

Provenance & Evidence