Water → ethyl 5-cyclopropyl-1-(4-ethoxy-2,6-difluorobenzyl)-4-methyl-1H-pyrazole-3-carboxylate

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Reaction Steps

46.9 g of ethyl 5-cyclopropyl-4-methyl-1H-pyrazole-3-carboxylate 1-15-1 (266 mmol, 1.0 eq.) in 588 mL THF were cooled to 0° C. and 11.6 g sodiumhydride (60%, 290 mmol, 1.2 eq.) were added in small portions. The resulting suspension was diluted with 250 mL THF. 66.7 g 2-(bromomethyl)-5-ethoxy-1,3-difluorobenzene (266 mmol, 1.1 eq., commercially available) were added slowly. The reaction mixture was stirred at rt for 2 hours. 300 mL water was added and the THF was evaporated in vacuum. The aqueous residue was extracted with ethylacetate three times. The combined organic layers were dried over a silicone filter and concentrated in vacuo. The residue was purified by flash chromatography to provide 79.8 g (195 mmol, 81%) of 89% pure target compound.

Provenance & Evidence