Methanol → 1-[3-Cyclopentyl-2-(4-pyridin-3-yl-phenyl)-propionyl]-3-methyl-urea

Participants

Reaction Conditions

Reaction Steps

A mixture of 3-cyclopentyl-2-(4-pyridin-3-yl-phenyl)-propionic acid methyl ester (275 mg, 0.89 mmol) and methyl urea (165 mg, 2.22 mmol) was treated with a solution of magnesium methoxide in methanol (7.4 wt. %, 5.5 mL, 2.67 mmol). The reaction mixture was then concentrated in vacuo to approximately one-half the volume of methanol. The resulting reaction mixture was then heated under reflux for 3 d. The reaction mixture was allowed to cool to 25° C. and then partitioned between water and ethyl acetate. The layers were separated, and the aqueous layer was further extracted with ethyl acetate (2×40 mL). The combined organic extracts were dried over magnesium sulfate, filtered, and concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230-400 mesh, 1/3 hexanes/ethyl acetate) afforded 1-[3-cyclopentyl-2-(4-pyridin-3-yl-phenyl)-propionyl]-3-methyl-urea (17 mg, 6%) as a white solid: mp 158-160° C.; FAB-HRMS m/e calcd for C21H25N3O2 (M+H)+ 352.2025, found 352.2028.

Provenance & Evidence