5-[2-(5-Chloro-2-methoxy-phenyl)-2-oxo-ethylcarbamoyl]-pentanoic acid methyl ester → 5-[5-(5-Chloro-2-methoxy-phenyl)-oxazol-2-yl]-pentanoic acid methyl ester

Participants

Reaction Steps

Dissolve 5-[2-(5-Chloro-2-methoxy-phenyl)-2-oxo-ethylcarbamoyl]-pentanoic acid methyl ester (9.39 g, 27.47 mmol) and 4-(dimethylamino)pyridine (6.54 g, 53.53 mmol) in 250 mL of CH2Cl2 and cool the reaction mixture in an ice bath. Add triphenylphosphinedibromide (22.54 g, 53.40 mmol) to the reaction portionwise over 15 minutes. Raise the reaction to ambient temperature and allow it to stir for 17 hours. Wash the reaction with water (1×) and brine (2×). Dry the organic layers with MgSO4. Filter off the drying agent and concentrate in vacuo to afford a crude residue. Purify the residue using silica gel chromotagraphy eluting with hexanes/ethyl acetate mixtures to afford 4.38 g of the titled product (49%): mass spectrum: m/z 324.1 (M+H).

Provenance & Evidence