Hydrochloric Acid → 5-((3,3-Dimethylbutanoyl)amino)-3-(4-isopropylphenyl)-4,6-dimethyl-2,3-dihydro-1-benzofuran-7-carboxylic acid

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Reaction Steps

To a mixed solution of N-(7-formyl-3-(4-isopropylphenyl)-4,6-dimethyl-2,3-dihydro-1-benzofuran-5-yl)-3,3-dimethylbutanamide (500 mg, 1.23 mmol) obtained in Example 20, sodium dihydrogenphosphate (40 mg), and hydrogen peroxide (0.125 mL) in acetonitrile (5 mL)-water (2 mL) was added at room temperature a solution of sodium chlorite (190 mg, 1.69 mmol) in water (2 mL) and the resulting mixture was stirred at the same temperature for 2 hours. To the reaction solution was added an aqueous sodium hydrogensulfite solution, added 1 N hydrochloric acid to make the mixture acidic, and the mixture was extracted with ethyl acetate. The extracts were washed with water, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The obtained residue was crystallized from hexane-ethyl acetate to obtain 380 mg (yield: 73%) of the title compound. Melting point: 194-195° C.

Provenance & Evidence