Sulfuric Acid → 5-Isoxazoleacetic acid, 3,4-bis(4-methoxyphenyl)-, methyl ester

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Reaction Steps

Methyl 5-hydroxyimino-4,5-bis(4-methoxyphenyl)-3-pentenoate (3.7 g) in 40 ml of acetic acid was stirred at 60° C. for 24 hours while blowing air into the mixture in the presence of 0.4 g of cobalt acetate. After completion of the reaction, 3N sulfuric acid was added and the resulting mixture was extracted with ethyl acetate. The organic layer was washed with saturated aqueous potassium carbonate solution and saturated aqueous sodium chloride solution in that order, and dried over anhydrous magnesium sulfate. The organic layer was then concentrated under reduced pressure and the residue was separated and purified by silica gel column chromatography (developing solvent: ethyl acetate:n-hexane=1:2) to give 3.3 g (yield 90%) of 5-methoxycarbonylmethyl-3,4-bis(4-methoxyphenyl)isoxazole.

Provenance & Evidence