Pyridine → trans-6-pentafluoroethyl-2,2-bisfluoromethyl-3,4-dihydro-4-[(1,6-dihydro-1-methyl-6-oxo-3-pyridazinyl)oxy]-2H-1-benzopyran-3-ol

Participants

Reaction Steps

A mixture of 0.58 g of 3,4-epoxy-6-pentafluoroethyl-2,2-bisfluoromethyl-3,4-dihydro-2H-1-benzopyran, 0.22 g of 3-hydroxy-1-methyl-1,6-dihydropyridazin-6-one, 0.16 g of pyridine and 5 ml of ethanol was refluxed for 5 hours. The solvent was distilled off and the resultant residue was purified using silica gel column chromatography (developing solution, MeOH:CH2Cl2 =1:99) to obtain 0.60 g of trans-6-pentafluoroethyl-2,2-bisfluoromethyl-3,4-dihydro-4-[(1,6-dihydro-1-methyl-6-oxo-3-pyridazinyl)oxy]-2H-1-benzopyran-3-ol represented by the following formula having a melting point of 189°-191° C. in Example 20.

Provenance & Evidence