Phenyl thioxochloroformate → 6-cyano-2,2-dimethyl-4-{1,2-dihydro-2-oxo-4-(1-phenoxythiocarbonyloxy-3-t-butyldimethylsilyloxypropyl)-1-pyridinyl}-2H-benzo[b]pyran

Participants

Reaction Steps

In 30 ml of anhydrous acetonitrile, is dissolved 1.46 g of 6-cyano-2,2-dimethyl-4-{2-oxo-4-(1-hydroxy-3-t-butyldimethylsilyloxypropyl)-1-pyridinyl}-2H-benzo[b]pyran obtained in Example 38. Then, 0.73 g of 4-dimethylaminopyridine and 0.79 ml of phenoxythiocarbonyl chloride are added at room temperature, and reacted at that temperature for 6 hours. After stopping the reaction by adding 0.1M aqueous solution of sodium hydrogen carbonate, the reaction mixture is extracted with ether. The organic layer is washed successively with water 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 1/2 mixture of ethyl acetate/n-hexane as a developing solvent. Thus, 1.20 g of 6-cyano-2,2-dimethyl-4-{1,2-dihydro-2-oxo-4-(1-phenoxythiocarbonyloxy-3-t-butyldimethylsilyloxypropyl)-1-pyridinyl}-2H-benzo[ b]pyran is obtained.

Provenance & Evidence