Sulfuric acid magnesium salt (1:1) → 2-(3-Cyclobutoxy-4-difluoromethoxyphenyl)-3-iodo-1-(2-trimethylsilylethoxymethyl)-1,5-dihydropyrrolo-[2,3-d]pyridazin-4-one

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Reaction Steps

To 283 mg (0.593 mmol) of 2-(3-cyclobutoxy-4-difluoromethoxyphenyl)-1-(2-trimethylsilylethoxymethyl)-1,5-dihydropyrrolo[2,3-d]pyridazin-4-one obtained in Example 31-(a) were added 1.6 ml of dichloromethane and 5 ml of acetonitrile, then, 167 mg of sodium hydrogencarbonate and 367 mg of anhydrous magnesium sulfate were added to the mixture, and the resulting mixture was stirred at room temperature for 30 minutes. Then, 3 ml of dichloromethane solution containing 267 mg of iodine chloride was added to the same, and the resulting mixture was further stirred at room temperature for 4 hours. After completion of the reaction, a filtrate obtained by removing insoluble material in the reaction suspension by filtration and a washed solution obtained by washing the filtered solid with ethyl acetate were combined and the combined solution was washed successively with 5% aqueous sodium thiosulfate solution and then with a saturated aqueous solution of sodium chloride. The organic layer after washing was dried over anhydrous magnesium sulfate and then concentrated under reduced pressure. The obtained residue was applied to silica gel column chromatography (Eluent; hexane:ethyl acetate=9:1→0:1 (V/V)), and the fractions containing the desired compound were concentrated under reduced pressure to obtain 314 mg of the title compound as a pale yellowish foam. (Yield: 88%)

Provenance & Evidence