Ammonium Chloride → 6-cyano-2,2-dimethyl-4-{1,2-dihydro-2-oxo-4-(1-hydroxy)ethyl-1-pyridinyl}-2H-benzo[b]pyran

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Reaction Steps

In 4 ml of anhydrous tetrahydrofuran, is dissolved 355 mg of 6-cyano-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-formyl-1-pyridinyl)-2H-benzo[b]pyran obtained in Example 25. Then, 1.73 ml of 0.94 M solution of methylmagnesium bromide in tetrahydrofuran is added at 0° C. and reacted first at that temperature for 50 minutes and then at room temperature for 20 minutes. After stopping the reaction by adding a saturated aqueous solution of ammonium chloride, the reaction mixture is extracted with ethyl acetate, and 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 thus obtained is purified by silica gel column chromatography using 1/1 mixture of methylene chloride/ethyl acetate as a developing solvent. Thus, 281 mg of 6-cyano-2,2-dimethyl-4-{1,2-dihydro-2-oxo-4-(1-hydroxy)ethyl-1-pyridinyl}-2H-benzo[b]pyran is obtained.

Provenance & Evidence