[CH2:1]([O:3][C:4](=[O:18])[CH:5]([CH2:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)[CH2:6][S:7](Cl)(=[O:9])=[O:8])[CH3:2].[CH3:19][NH:20][CH3:21].Cl>C(Cl)Cl.C(O)C>[CH2:1]([O:3][C:4](=[O:18])[CH:5]([CH2:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)[CH2:6][S:7]([N:20]([CH3:21])[CH3:19])(=[O:9])=[O:8])[CH3:2]A solution of 359 mg of 2-benzyl-3-chlorosulphonylpropionic acid ethyl ester in 2 ml of methylene chloride is cooled to -10° and 0.464 ml of a 5.6M solution of dimethylamine in ethanol is added thereto. The solution is stirred for 15 minutes at -15°, mixed with 2N HCl and extracted with methylene chloride. The extracts are washed with water, dried with magnesium sulphate and concentrated by evaporation. The residue is chromatographed on silica gel with eluant C. Rf (A)=0.43.
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