Hydrochloric Acid → 2-Hydroxy-4-[4-[3-(5-methyl-2-phenyl-4-oxazolyl) propionyl)phenyl]butyric acid

Participants

Reaction Steps

A mixture of 2-acetoxy-4-[4-[3-(5-methyl-2-phenyl-4-oxazolyl)propionyl]phenyl]butyronitrile (1.72 g), 6 N HCl (20 ml) and dioxane (10 ml) was heated under refluxing conditions for 3 hours. The reaction mixture was poured over water and extracted with ethyl acetate. The ethyl acetate layer was washed with water, dried (MgSO4) and then concentrated under reduced pressure to yield 2-hydroxy-4-[4-[3-(5-methyl-2-phenyl-4-oxazolyl) propionyl)phenyl]butyric acid as a solid substance. The solid was dissolved in ethanolic hydrogen chloride (10%, w/w, 20 ml), followed by stirring at 75°-80° C. for 2 hours. The reaction mixture was poured over water and extracted with ethyl acetate. The ethyl acetate layer was washed with water, dried (MgSO4) and then concentrated under reduced pressure; the residue was subjected to silica gel column chromatography. From the fraction eluted with ethyl acetate-hexane (1:1), 2-hydroxy-4-[4-[3-(5-methyl-2-phenyl4-oxazolyl)propionyl]phenyl]butyric acid ethyl ester (1.54 g, 88%) was obtained, which was then recrystallized from dichloromethane-isopropyl ether to yield colorless needles having a melting point of 87°-88° C.

Provenance & Evidence