1-Bromo-2-Chloroethane → 4-[4-Benzenesulfonyl-2-(2-chloro-ethoxy)-phenylamino]-piperidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a solution of 4-(4-benzenesulfonyl-2-hydroxy-phenylamino)-piperidine-1-carboxylic acid tert-butyl ester (0.192 g., 0.444 mmol) in 1 mL acetonitrile is added potassium carbonate (0.245 g., 1.776 mmol) and then 1-bromo-2-chloro-ethane (0.044 mL, 0.535 mmol) dropwise. The suspension is refluxed under nitrogen for 3 hours, at which time is added 1-bromo-2-chloro-ethane (0.044 mL, 0.535 mmol) dropwise. Reflux is continued for another 1.5 hours. The reaction mixture is concentrated in vacuo and the resulting oil is dissolved in 75 mL ethyl acetate, washed with 2×50 mL water and 50 mL brine, then dried over sodium sulfate and concentrated in vacuo. The resulting crude oil is purified by flash chromatography (10% -30% ethyl acetate in hexanes) to give 0.175 g (0.35 mmol, 80%) of 4-[4-benzenesulfonyl-2-(2-chloro-ethoxy)-phenylamino]-piperidine-1-carboxylic acid tert-butyl ester as a clear oil. MS: 439 (M−tBu+H)+.

Provenance & Evidence