Water → Rac-cyclopentylsulfanyl-(3,4-dichloro-phenyl)-acetic acid methyl ester

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Reaction Conditions

Reaction Steps

A solution of diazo-(3,4-dichloro-phenyl)-acetic acid methyl ester (Example 1; 193 mg, 0.79 mmol) in dichloromethane (10 mL) at 25° C. was treated with cyclopentyl mercaptan (0.21 mL, 1.97 mmol) followed by rhodium (II) acetate dimer (9 mg, 0.020 mmol) and the solution was stirred at 25° C. for 1 h. During this time no evolution of gas was detected, and examination of the black solution by thin layer chromatography indicated that only starting material was present. The reaction was heated to reflux and a second portion of rhodium (II) acetate dimer (10 mg, 0.024 mmol) was added and as the mixture was stirred at reflux for 110 min, a vigorous evolution of gas was observed. The reaction mixture was diluted with dichloromethane (10 mL), then was poured into water (15 mL) and extracted with dichloromethane (3×10 mL). The combined organic extracts were dried over sodium sulfate, filtered and evaporated under reduced pressure. The residual oil was purified by flash chromatography (Merck Silica gel 60, 230-400 mesh, 95/5 hexanes/ethyl acetate) to furnish rac-cyclopentylsulfanyl-(3,4-dichloro-phenyl)-acetic acid methyl ester (148 mg, 59% yield) as a colorless oil: EI-HRMS m/e calcd for C14H16Cl2SO2(M+) 318.0248, found 318.0244.

Provenance & Evidence