Oxalyl chloride → {2-[2-(4-Chloro-phenyl)-3-cyclopentyl-propionylamino]-thiazol-4-yl}-acetic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of 2-(4-chloro-phenyl)-3-cyclopentyl-propionic acid (252 mg, 1.0 mmol) in methylene chloride (10 mL) was cooled to 0° C. and then treated with a 2.0 M solution of oxalyl chloride in methylene chloride (0.55 mL, 1.1 mmol) and a few drops of N,N-dimethylformamide. The reaction mixture was stirred at 0° C. for 15 min and then at 25° C. for 1.5 h. The reaction mixture was then treated with (2-amino-thiazol-4-yl)-acetic acid ethyl ester (409 mg, 2.2 mmol) and N,N-diisopropylethylamine (0.5 mL, 2.4 mmol). This solution was stirred at 25° C. for 24 h. At this time, the reaction was concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230-400 mesh, 85/15 hexanes/ethyl acetate) afforded {2-[2-(4-chloro-phenyl)-3-cyclopentyl-propionylamino]-thiazol-4-yl}-acetic acid ethyl ester (183.3 mg, 43.5%) as a pale yellow oil: EI-HRMS m/e calcd for C21H25ClN2O3S (M+) 420.1274, found 420.1272.

Provenance & Evidence