Potassium Hydroxide → {2-[3-Cyclopentyl-2-(4-phenoxy-phenyl)-propionylamino]-thiazol-4-yl}-acetic acid

Participants

Reaction Conditions

Reaction Steps

A solution of {2-[3-cyclopentyl-2-(4-phenoxy-phenyl)-propionylamino]-thiazol-4-yl}-acetic acid ethyl ester (prepared in Example 12B-a, 276 mg, 0.58 mmol) in ethanol (20 mL) at 25° C. was treated with a solution of potassium hydroxide (100 mg, 1.78 mmol) in water (6 mL). This light yellow solution was stirred at 25° C. for 2 h and then concentrated in vacuo to remove ethanol. The resulting aqueous solution was acidified to pH=2 with a 1N aqueous hydrochloric acid solution and then extracted with methylene chloride (3×10 mL). The combined organic extracts were dried over sodium sulfate, filtered, and concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230-400 mesh, 10/90 hexanes/ethyl acetate plus 1% acetic acid) afforded {2-[3-cyclopentyl-2-(4-phenoxy-phenyl)-propionylamino]-thiazol-4-yl}-acetic acid (222 mg, 80%) as a white foam: FAB-HRMS m/e calcd for C25H26N2O4S (M+H)+ 451.1691, found 451.1686.

Provenance & Evidence