Water → 6-cyano-2,2-dimethyl-4-{1,2-dihydro-2-oxo-4-(4-hydroxybutyl)-1-pyridinyl}-2H-benzo[b]pyran

Participants

Reaction Steps

In 24 ml of methylene chloride, is dissolved 1.13 g of 6-cyano-2,2-dimethyl-4-{2-oxo-4-(4-p-methoxybenzyloxybutyl)-1-pyridinyl}-2H-benzo[b]pyran obtained in Example 46. Then, 1.33 ml of water is added. Then, 0.82 g of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone is added at room temperature and the resulting mixture is reacted at that temperature for 40 minutes. After stopping the reaction by adding water, the reaction mixture is extracted with methylene chloride. The organic layer is washed successively with 0.1M aqueous solution of sodium hydrogen carbonate and 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, 0.78 g of 6-cyano-2,2-dimethyl-4-{1,2-dihydro-2-oxo-4-(4-hydroxybutyl)-1-pyridinyl}-2H-benzo[b]pyran is obtained.

Provenance & Evidence