Hydrochloric Acid → 6-cyano-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-(3-hydroxypropyl)-1-pyridinyl}-2H-benzo[b]pyran

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Reaction Steps

In 7.50 ml of methanol, is dissolved 819 mg of 6-cyano-2,2-dimethyl-4-{2-oxo-4-(3-t-butyldimethylsilyloxypropyl)-1-pyridinyl}-2H-benzo[b]pyran obtained in Example 40. Then, 1.90 ml of 4N hydrochloric acid in dioxane is added thereto at 0° C., and reacted at room temperature for 30 minutes. The reaction mixture is concentrated under reduced pressure, the residue is mixed with ethyl acetate and water, and the product is extracted into ethyl acetate. The organic layer is washed with saturated aqueous solution of sodium chloride and dried over anhydrous sodium sulfate. The inorganic matter is filtered off, and the filtrate is concentrated under reduced pressure. The residue is purified by silica gel column chromatography using 1/10 mixture of methanol/methylene chloride as a developing solvent. Thus, 577 mg of 6-cyano-2,2-dimethyl-4-{1,2-dihydro-2-oxo-4-(3-hydroxypropyl)-1-pyridinyl}-2H-benzo[b]pyran is obtained.

Provenance & Evidence