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

Beteiligte Stoffe

Reaktionsschritte

In 10 ml of acetonitrile, is dissolved 314 mg of 6-cyano-2,2-dimethyl-4-{2-oxo-4-(1-hydroxy-2-ethoxycarbonylethyl)-1-pyridinyl}-2H-benzo[b]pyran obtained in Example 31. Then, 195 mg of 4-dimethylaminopyridine and 0.17 ml of phenoxythiocarbonyl chloride are added at room temperature and reacted at that temperature for 19.5 hours. After stopping the reaction by adding 0.1M aqueous solution of sodium hydrogen carbonate, the reaction mixture is extracted with ethyl acetate. 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 2/3 mixture of ethyl acetate/n-hexane. Thus, there are obtained 77 mg of 6-cyano-2,2-dimethyl-4-{1,2-dihydro-2-oxo-4-(1-phenoxythiocarbonyloxy-2-ethoxycarbonylethyl)-1-pyridinyl}-2H-benzo[b]pyran and, as a by-product, 20 mg of 6-cyano-2,2-dimethyl-4-{1,2-dihydro-2-oxo-4-(2-ethoxycarbonylethenyl)-1-pyridinyl}-2H-benzo[b]pyran.

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