To a solution of 2-[(3,4-dimethoxyphenyl)thio]-3-(3-phenylpropyl-1-yl)-1-cyclopentenecarboxylic acid (0.6 g, 1.5 mmol) in dichloromethane (20 mL) is added 2 M oxalyl chloride (1.5 mL, 3 mmol). The mixture is stirred at room temperature for 15 minutes. The solvent is removed in vacuo and the residue is dissolved in dichloromethane and O-(trimethylsilyl)hydroxylamine (0.3 mL, 3 mmol) is added. The mixture is stirred at room temperature for 30 minutes. The mixture is poured into 5% HCl and is extracted with dichloromethane. The organic layer is washed with water and is dried over MgSO4. The solvent is removed in vacuo and the residue is chromatographed on silica gel (100% ethyl acetate). The product is dissolved in the minimum amount of ethyl acetate and the solution is diluted to the cloudy point with hexane to precipitate N-hydroxy-2-[(3,4-dimethoxyphenyl)thio]-3-(3-phenylpropyl-1-yl)-1-cyclopentenecarboxamide on standing at room temperature overnight (0.1 g, 16%): m.p. 44-6° C. Anal. (C23H27NO4S.1/4H2O) C,H,N: 1H-NMR (300 MHz, CDCl3) δ (TMS) 1.42-1.78 (m, 5H), 1.90-2.08 (m, 1H), 2.38-2.50 (m, 2H), 2.59-2.78 (m, 3H), 3.82 (s, 3H), 3.90 (s, 3H), 6.72-6.79 (d, 1H), 6.88-6.98 (m, 2H), 6.98-7.10 (d, 2H), 7.10-7.30 (m, 3H), 9.02 (s, 1H); MS (Ion Spray) m/e 413 (M+H)+.
