To a suspension of 1-(2-chlorophenyl)-5-{5-[3-(methylsulfonyl)phenyl]-2-thienyl}-1H-pyrazole-3-carboxylic acid (92 mg, 0.2 mmol) in DCM (2 mL) was added carbonyldiimidazole (39 mg, 1.2 equiv) and stirring was continued for 2 h at 20° C. A solution of ethylamine in THF (1.8 M, 0.17 mL, 1.5 equiv) was added and the mixture was stirred overnight at 20° C. Evaporation of solvent gave a crude, which was purified by column chromatography on silica gel eluting with MeOH-DCM (1:19) to afford 1-(2-chlorophenyl)-N-ethyl-5-{5-[3-(methylsulfonyl)phenyl]-2-thienyl}-1H-pyrazole-3-carboxamide (84 mg). 1H-NMR (CDCl3): δ 8.03 (m, 1H), 7.83 (m, 1H), 7.74 (m, 1H), 7.62-7.45 (m, 5H), 7.22 (m, 1H), 7.19 (s, 1H), 6.91 (m, 1H), 6.82 (d, 1H), 3.55-3.43 (m, 2H), 3.07 (3 s, H), 1.25 (s, 3H). MS(ES): 486 [M+H]+.
