Methyl Isocyanate → 1-[3-Cyclopentyl-2(R)-(3,4-dichloro-phenyl)-propionyl]-3-methyl-urea

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Reaction Steps

A solution of 3-cyclopentyl-2(R)-(3,4-dichloro-phenyl)-propionamide (54 mg, 0,19 mmol) in toluene (5 mL) was treated with methyl isocyanate (0.03 mL, 0.47 mmol). The resulting solution was heated under reflux for 24 h. At this time, the reaction was concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230-400 mesh 70/30 hexanes/ethyl acetate) afforded 1-[3-cyclopentyl-2(R)-(3,4-dichloro-phenyl)-propionyl]-3-methyl-urea (40 mg, 63%) as a white solid: mp 124.8-127.5° C.; [α]23589=−21.2° (c=0.099, chloroform); EI-HRMS m/e calcd for C16H20Cl2N2O2 (M+) 342.0902, found 342.0902.

Provenance & Evidence