Water → ethyl 3-(hydroxymethyl)-1-methyl-4-(trifluoromethyl)-1H-pyrazole-5-carboxylate

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Reaction Steps

A solution of 6.00 g (20.4 mmol) of diethyl 1-methyl-4-(trifluoromethyl)-1H-pyrazole-3,5-dicarboxylate in 80 ml of tetrahydrofuran is admixed under argon at −78° C. with 38.9 ml (42.8 mmol) of a 1.1M solution of diisobutylaluminium hydride in cyclohexane and stirred overnight at this temperature. The reaction mixture is admixed with water and extracted twice with ethyl acetate. The organic phase is dried over sodium sulphate, filtered over silica gel and concentrated by evaporation in vacuo. Chromatographic purification on silica gel gives 4.10 g of ethyl 3-(hydroxymethyl)-1-methyl-4-(trifluoromethyl)-1H-pyrazole-5-carboxylate (80%).

Provenance & Evidence