反应详情

A solution of {2-[3-cyclopentyl-2-(4-nitro-phenyl)-propionylamino]-thiazol-4-yl}-acetic acid ethyl ester (prepared as in Example 23, 160 mg, 0.37 mmol) in methanol (10 mL) was treated with a catalytic amount of sulfuric acid. The reaction mixture was heated under reflux for 68 h. The reaction was concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230-400 mesh, 75/25 hexanes/ethyl acetate) afforded {2-[3-cyclopentyl-2-(4-nitro-phenyl)-propionylamino]-thiazol-4-yl}-acetic acid methyl ester (82.3 mg, 53.3%) as a pale yellow oil: FAB-HRMS m/e calcd for C20H23N3O5S (M+H)+ 418.1436, found 418.1424.

1. temperatureThe reaction mixture was heated
2. temperatureunder reflux for 68 h
3. concentrationThe reaction was concentrated in vacuo