Hydrogen Peroxide → 1-[3-Cyclopentyl-2-(3,4-dichloro-phenyl)-propionyl]-3-(2-hydroxy-propyl)-urea

Participants

Reaction Conditions

Reaction Steps

A solution of 1-allyl-3-[3-cyclopentyl-2-(3,4-dichloro-phenyl)-propionyl]-urea (prepared in Example 12B-e, 132 mg, 0.36 mmol) in tetrahydrofuran (10 mL) cooled to 0° C. was treated with a 1M solution of borane-tetrahydrofuran (0.7 mL, 0.72 mmol). The reaction mixture was allowed to warm from 0° C. to 25° C. over 1 h. At this time, the solution was re-cooled to 0° C. and treated with ethanol (2 mL) followed by the slow addition of a mixture of a saturated aqueous sodium bicarbonate solution (6 mL) and 30% hydrogen peroxide (2 mL). The resulting mixture was allowed to slowly warm to 25° C. over 1 h. At this time, the reaction was re-cooled to 0° C. and was slowly quenched with a saturated aqueous sodium sulfite solution (20 mL). This mixture was extracted with ethyl acetate (3×20 mL). The organics were washed with a saturated aqueous sodium chloride solution (1×15 mL), dried over sodium sulfate, and concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230-400 mesh, 80/20 hexaneslethyl acetate) effected the separation of two spots, the first of the two product spots to elute off the column afforded 1-[3-cyclopentyl-2-(3,4-dichloro-phenyl)-propionyl]-3-(2-hydroxy-propyl)-urea (36 mg, 26%) as a white solid: mp 116.7-119.9° C.; EI-HRMS m/e calcd for C18H24Cl2N2O3 (M+) 386.1164, found 386.1173.

Provenance & Evidence