In 6 ml of methylene chloride is dissolved 0.62 g of 4-isobutoxy-3-(2-methoxy-2-oxoethyl)benzoic acid. After adding 0.25 ml of oxalyl chloride at ambient temperature, the mixture thus obtained is stirred at ambient temperature for one hour. Then, 0.62 g of aluminum chloride and 0.77 g of 1,3-diisobutoxybenzene are successively added at 5-10° C., and the mixture is stirred at ambient temperature for one hour. The reaction mixture is added to a mixture of chloroform and water, and the organic layer is separated. The organic layer is successively washed with water and saturated aqueous solution of sodium chloride and dried over anhydrous magnesium sulfate, and the solvent is distilled off under reduced pressure. The residue thus obtained is purified by silica gel column chromatography [eluent; n-hexane:ethyl acetate=95:5] to obtain 0.63 g of methyl 2-[5-(2,4-diisobutoxybenzoyl)-2-isobutoxyphenyl]acetate as a colorless oily product.
