Triethylamine → 3,3-Dimethyl-4-fluoro-1-(6-fluoro-pyridin-2-yl-oxy)-1-(1,2,4-triazol-1-yl)-butan-2-one

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Reaction Steps

18.5 g (0.1 mole) of 3,3-dimethyl-4-fluoro-1-(1,2,4-triazol-1-yl)-butan-2-one were dissolved in 150 ml of glacial acetic acid, and, after adding 8.2 g (0.1 mole) of sodium acetate, 16 g (0.1 mole) of bromine were added dropwise at 45° C., until the mixture was completely decolorized. The mixture was then poured into ice-water and extracted with chloroform. The combined chloroform extracts were washed with sodium bicarbonate solution, dried over magnesium sulphate and concentrated. The oily 1-bromo-3,3-dimethyl-4-fluoro-1-(1,2,4-triazol-1-yl)-butan-2-one which remained was dissolved in 50 ml of acetonitrile, and 11.3 g (0.1 mole) of 6-fluoro-2-hydroxy-pyridine and 10.5 g (0.1 mole) of triethylamine, both dissolved in 120 ml of acetonitrile, were added, while stirring. The mixture was stirred under reflux for 1 hour. It was then concentrated by distilling off the solvent in vacuo, and the residue was stirred with water. The crystalline precipitate formed was filtered off and recrystallized from cyclohexane. 20 g (68% of theory) of 3,3-dimethyl-4-fluoro-1-(6-fluoro-pyridin-2-yl-oxy)-1-(1,2,4-triazol-1-yl)-butan-2-one of melting point 116° C. were obtained.

Provenance & Evidence