Acetic Anhydride → 4-[3-(3-Acetoxy-4-acetyl-2-propylphenoxy)propoxy]-3-bromobenzoic acid

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Reaction Steps

In a mixture of pyridine (10 ml) and acetic anhydride (10 ml) was dissolved 4-[3-(4-acetyl-3-hydroxy-2-propylphenoxy)propoxy]-3-bromobenzoic acid (2 g). The solution was heated at 100° to 120° C. for 14 hours, which was then concentrated. The residue was dissolved in chloroform. The solution was washed with dilute hydrochloride acid, which was then dried on sodium sulfate. From the resultant was removed the solvent by evaporation, and the residue was chromatographed on a column of silica gel. Elution was conducted with hexane-ethyl acetate (3:1), (2:1), (1:1) and ethyl acetate in that order. Ethyl acetate fractions were combined and concentrated. The residue was crystallized from chloroform-hexane to give 4-[3-(3-acetoxy-4-acetyl-2-propylphenoxy)propoxy]-3-bromobenzoic acid (1.0 g), m.p. 155°-156° C.

Provenance & Evidence