[F:1][C:2]1[C:3]([O:9][CH3:10])=[N:4][CH:5]=[C:6]([OH:8])[CH:7]=1.[OH-].[K+].CN(C)C=O.[F:18][C:19]([F:23])=[C:20]([F:22])[F:21]>CCOCC.O>[F:1][C:2]1[C:3]([O:9][CH3:10])=[N:4][CH:5]=[C:6]([O:8][C:20]([F:22])([F:21])[CH:19]([F:23])[F:18])[CH:7]=1
3-Fluoro-2-methoxy-5-pyridinol (1.60 g, 11.2 mmol) and 0.04 g (0.7 mmol) of potassium hydroxide were added to 10 ml of dimethylformamide and the mixture blanketed with nitrogen and heated to 70° C. with stirring. An excess of tetrafluoroethylene was introduced into the liquid by means of a sparge tube. After stirring 4 hours at 70° C. no reaction was observed so another 0.04 g of potassium hydroxide was added and the tetrafluoroethylene addition continued. The reaction was indicated to be complete by F19 nmr after 3 hours. The mixture was allowed to cool and was then poured into a mixture of 50 ml of water and 60 ml of ether. The ethereal layer was extracted with 2-25 ml portions of water and one of saturated aqueous sodium chloride and dried over sodium sulfate. The combined aqueous extracts were extracted with ether and the ethereal layer dried. The combined ethereal solutions were concentrated by evaporation under reduced pressure to obtain 1.65 g of the title compound as a yellow oil. The proton nmr spectrum was consistent with the assigned structure.
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