Lithium Hydroxide → 5-[(4-fluorophenyl)methyl]-3-(4-pyridinyl)-1H-Pyrazole-1-acetic acid

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Reaction Steps

A 12 liter, three-neck, round bottom flask equipped with mechanical stirrer was charged with Methyl [5-(4-fluorobenzyl)-3-pyridin-4-yl-1H-pyrazol-1-yl]acetate (235 g, 0.72 mol), THF (3.5 L), methanol (1.2 L), and 2 M LiOH (1.2 L). The resulting solution was stirred at room temperature for 1.5 hours. After LC-MS showed the absence of starting material, the majority of the THF was removed by rotary evaporation. The solution was then acidified with 2 M HCl (pH=3) and the white precipitate was filtered and washed with water. After being dried under reduced pressure, 210 g (93%) of the title compound was obtained. 1H NMR (400 MHz, DMSO-D6) δ ppm 8.53 (d, 2 H), 7.68 (d, 2 H), 7.31 (t, 2 H), 7.14 (t, 2 H), 6.57 (s, 1 H), 5.00 (s, 2 H), 4.01 (s, 2 H); m/z (APCI+) for C17H14N3O2F 312.2 (M+H)+.

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