反应详情

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.

1. temperatureThe solution was heated at 100° to 120° C. for 14 hours
2. concentrationwhich was then concentrated
3. dissolutionThe residue was dissolved in chloroform
4. washThe solution was washed with dilute hydrochloride acid, which
5. customwas then dried on sodium sulfate
6. customFrom the resultant was removed the solvent
7. customby evaporation
8. customthe residue was chromatographed on a column of silica gel
9. washElution
10. concentrationconcentrated
11. customThe residue was crystallized from chloroform-hexane