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

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Reaction Steps

In 50 ml of anhydrous tetrahydrofuran, is dissolved 1.32 g of trans-3-hydroxy-6-cyano-3,4-dihydro-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-t-butyldimethylsilyloxymethyl-1-pyridinyl)-2H-benzo[b]pyran obtained is Example 1. Then, 0.12 g of 60% oily sodium hydride is added to the solution at room temperature and reacted under reflux for 4 hours. After stopping the reaction by adding water, the reaction mixture is extracted with ether. The organic layer is successively washed with water and saturated aqueous solution of sodium chloride and dried over anhydrous sodium sulfate. Then, the inorganic matter is filtered off and the filtrate is concentrated under reduced pressure. The residue is purified by silica gel column chromatography using 1/7 mixture of ethyl acetate/methylene chloride as a developing solvent. Thus, 1.04 g of 6-cyano-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-t-butyldimethylsilyloxymethyl-1-pyridinyl)-2H-benzo[b]pyran is obtained.

Provenance & Evidence