4-Chlorobenzenesulfonyl chloride → 1-(4-Chlorophenylsulfonyl)-4-(4-chlorophenylsulfonylamino) pyrrolidine

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Reaction Steps

To a solution of (2S,4R)-2-[(E and Z)-5-carboxy-1-pentenyl]-4-(4-chlorophenylsulfonylamino)pyrrolidine trifluoroacetate (7.85 g) in dichloromethane (80 ml) were added triethylamine (8.98 ml) and 4-chlorobenzenesulfonyl chloride (3.40 g) under an ice bath cooling and the mixture was stirred at the same temperature for 1.5 hours. The solution was washed successively with diluted hydrochloric acid and water and the organic phase was extracted with 1N aqueous sodium hydroxide. The aqueous phase was washed with ethyl acetate and adjusted to pH 3 with 3N hydrochloric acid. The aqueous solution was extracted with ethyl acetate and the organic phase was washed successively with water and brine and dried over magnesium sulfate. The solvent was evaporated in vacuo and the residue was chromatographed on a silica gel column with chloroform as an eluent to give (2S,4R)-2-[(E and Z)-5-carboxy-1-pentenyl]-1-(4-chlorophenylsulfonyl)-4-(4-chlorophenylsulfonylamino) pyrrolidine (2.03 g) as a pale yellow crystal.

Provenance & Evidence