C([O:3][C:4]([C:6]1[C:10]([CH3:11])=[C:9]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][C:13]=2[C:18]2[O:22][C:21]3[CH:23]=[CH:24][CH:25]=[CH:26][C:20]=3[CH:19]=2)[N:8]([CH3:27])[N:7]=1)=[O:5])C.[OH-].[Na+]>CS(C)=O.O>[O:22]1[C:21]2[CH:23]=[CH:24][CH:25]=[CH:26][C:20]=2[CH:19]=[C:18]1[C:13]1[CH:14]=[CH:15][CH:16]=[CH:17][C:12]=1[C:9]1[N:8]([CH3:27])[N:7]=[C:6]([C:4]([OH:5])=[O:3])[C:10]=1[CH3:11]A suspension of 0.615 g (1.71 mmol) of 5-(3-benzofuran-2-yl-phenyl)-1,4-dimethyl-1H-pyrazole-3-carboxylic acid ethyl ester in 5.50 ml of DMSO was treated at RT with 0.85 ml (3.41 mmol) of aqueous 1N NaOH. After 2 h, reaction was heated at 45° C. for 30 min. Then it was diluted with chilled water and extracted with Et2O. The water phase was acidified with aqueous 10% KHSO4 and extracted with Et2O (2×). These organic phases were washed with aqueous 10% NaCl, dried (Na2SO4) and evaporated to give 0.481 g (84%) of 5-(3-benzofuran-2-yl-phenyl)-1,4-dimethyl-1H-pyrazole-3-carboxylic acid as light brown powder. MS: 331.4 (M−H−).
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