[H-].[Na+].CN(C=O)C.[CH2:8]([OH:13])[C:9]([F:12])([F:11])[F:10].Br[C:15]1[CH:20]=[CH:19][C:18]([Br:21])=[CH:17][N:16]=1>O>[Br:21][C:18]1[CH:19]=[CH:20][C:15]([O:13][CH2:8][C:9]([F:12])([F:11])[F:10])=[N:16][CH:17]=1Sodium hydride (18.6 g, 60%, 464 mmol) was introduced into DMF (500 ml) under nitrogen. Trifluoroethanol (32.2 ml, 443 mmol) was added dropwise at 10° C. After 1 hour, 2,5-dibromopyridine (100 g, 422 mmol) was added portionwise, and the mixture was stirred in a water bath for 24 hours at 20° C. It was then stirred with water and extracted with heptane/ethyl acetate 9:1. Distillation of the crude product (105 g) yielded 5-bromo-2-trifluoroethoxypyridine, 82.1 g (purity 93%), colorless fluid, b.p. 97-104° C. at 18 mbar.
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