Lithium Hydroxide → 1-(2,2,2-trifluoroethyl)-1H-pyrazole-3-carboxylic acid

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Reaction Steps

Methyl 1-(2,2,2-trifluoroethyl)-1H-pyrazole-3-carboxylate (Intermediate 204, 0.312 g, 1.5 mmol) was dissolved in a mixture of THF (2 mL), MeOH (2 mL) and water (1 mL); lithium hydroxide (0.188 g, 4.5 mmol) was added and the mixture was stirred at room temperature for 16 h. The mixture was concentrated, the residue dissolved in water (1 mL) and the mixture was neutralised. This was extracted with EtOAc (2×10 mL), the organic extracts were dried over sodium sulfate and concentrated under vacuum. The crude material was washed with pentane (2×10 mL) to afford 1-(2,2,2-trifluoroethyl)-1H-pyrazole-3-carboxylic acid (0.200 g, 69%). 2-N-methyl-2-N-phenyl-6-{5-[1-(2,2,2-trifluoroethyl)-1H-pyrazol-3-yl]-1,2,4-oxadiazol-3-yl}-1,3,5-triazine-2,4-diamine was then prepared from 1-(2,2,2-trifluoroethyl)-1H-pyrazole-3-carboxylic acid (0.159 g, 0.820 mmol) and 4-amino-N-hydroxy-6-[methyl(phenyl)amino]-1,3,5-triazine-2-carboximidamide (prepared in an analogous manner to Intermediate 1, 0.125 g, 0.483 mmol) according to the method described for Example 251 to afford the title compound (0.110 g, 55%).

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