Lithium Hydroxide → [4-(4-fluorophenyl)-3-[4-(methylsulfonyl)phenyl]-5-(trifluoromethyl)-1H-pyrazol-1-yl]acetic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of ethyl [4-(4-fluorophenyl)-3-[4-(methylsulfonyl)phenyl]-5-(trifluoromethyl)-1H-pyrazol-1-yl]acetate (Example 8) (0.48 g, 1.0 mmol) in tetrahydrofuran (THF) (10 mL) was added 1.5 mL of 1N aqueous lithium hydroxide at 25° C. under nitrogen and the mixture stirred for 24 hours at 25° C. The reaction mixture was extracted with two portions diethyl ether and the aqueous layer was acidified with dilute aqueous HCl. This was extracted with two portions ethyl acetate which was washed with brine, dried over MgSO4 and concentrated in vacuo. Recrystallization from chloroform/acetone gave [4-(4-fluorophenyl)-3-[4-(methylsulfonyl)phenyl]-5-(trifluoromethyl)-1H-pyrazol-1-yl]acetic acid as a white crystalline solid (0.41 g, 93%). Elemental analysis for C19H14N2F4SO4Calc'd: C, 51.58, H, 3.19, N, 6.33. Found: C, 51.18, H. 3.23, N, 6.19;

Provenance & Evidence