2-Piperidone → 6-pentafluoroethyl-2,2-bisfluoromethyl-4-(2-oxo-1-piperidinyl)-2H-1-benzopyran

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Reaction Steps

To a mixture of 0.54 g of 3,4-epoxy-6-pentafluoroethyl-2,2-bisfluoromethyl-3,4-dihydro-2H-1-benzopyran, 0.24 g of 2-piperidinone and 10 ml of tetrahydrofuran was added 0.27 g of potassium tert-butoxide with stirring under ice-cooling. The mixture was stirred for 6 hours under ice-cooling and then stirred at room temperature for 16 hours. Ice water was added to the mixture, which was then extracted with methylene chloride. After the organic layer was washed with water and dried, the solvent was distilled off. The resultant residue was purified using silica gel column chromatography (developing solution, MeOH:CH2Cl2 =1:99) to obtain from the first eluted fraction 0.02 g of 6-pentafluoroethyl-2,2-bisfluoromethyl-4-(2-oxo-1-piperidinyl)-2H-1-benzopyran represented by the following formula having a melting point of 149-150° C.

Provenance & Evidence