Yield:926241-24-9 86%

Reaction Conditions:

with potassium tert-butylate;water in ethanol at 60;

Steps:

Intermediate 55: 2-[3-(trifluoromethyl)pyrazol-1 -yI]acetic acid

[00556] Intermediate 55: 2-[3-(trifluoromethyl)pyrazol-1 -yI]acetic acid[00557] A solution of ethyl 2-[3-(trifluoromethyl)pyrazol-1 -yl]acetate (120mg, 0.S4mmol) and potassium tert-butoxide (91 mg, 0.81 mmol) in EtCH (2mL) and water (0.01 mL, 0.81 mmol) was heated to 60 °C and left to stir overnight. The reaction mixture was quenched by the addition ofwater (2OmL) and extracted once with EtCAc (2OmL). The aqueous layer was acidified to pH 2 with conc. HCI and extracted with EtCAc (3 x 2OmL) These combined organic layers were dried over Na2SC4, filtered and concentrated in vacuo to give 2-[3-(trifluoromethyl)pyrazol-1-yl]acetic acid (90mg, 0.46mmol, 86% yield) as an orange solid.1H NMR (CDCI3,400MHz) O/ppm: 7.54 (1H, dd, J= 2.3Hz, 0.9Hz), 6.61 (1H, d, J= 2.2Hz), 5.04 (2H,5) exchangeable proton not seen.MS Method 2: RT: 1.18 mi m/z 195.0 [M+H]

References:

WO2016/51193,2016,A1 Location in patent:Paragraph 00553; 00556; 00557