Phenol → (S)-4-benzyl-2-(2-phenoxyethyl)piperazine-1-carboxylic acid tert-butyl ester

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Reaction Steps

Combine (S)-4-benzyl-2-(2-methanesulfonyloxyethyl)piperazine-1-carboxylic acid tert-butyl ester (2.82 g, 7.08 mmol), sodium iodide (0.106 g, 0.708 mmol), and phenol (3.33 g, 35.4 mmol) in dimethyl formamide (40 mL) and stir at 100° C. for 20 hours. Dilute the mixture with saturated aqueous sodium bicarbonate and extract three times with dichloromethane. Combine the organic layers, dry over sodium sulfate and concentrate under reduced pressure. Purify by flash chromatography, eluting with a step gradient (100% dichloromethane to 5% 2N ammonia-methanol in dichloromethane) to obtain (S)-4-benzyl-2-(2-phenoxyethyl)piperazine-1-carboxylic acid tert-butyl ester (0.703 g, 25%): mass spectrum (APCI): m/z=397.2 (M+1).

Provenance & Evidence