C([O:3][C:4]([C:6]1[N:7]([CH3:17])[N:8]=[C:9]([C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)[CH:10]=1)=[O:5])C.[OH-].[Na+]>CO>[CH3:17][N:7]1[C:6]([C:4]([OH:5])=[O:3])=[CH:10][C:9]([C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)=[N:8]1To a solution of 2-methyl-5-phenyl-2H-pyrazole-3-carboxylic acid ethyl ester (2.3 g, 10 mmol) in MeOH (30 mL) is added 1 N NaOH (12 mL) in one portion at RT. The mixture is stirred at RT for 1 h. Most of the MeOH is removed with a rotary evaporator, and the remaining aqueous solution is diluted with water (12 mL) and neutralized with 1 N HCl to pH=5. The precipitate is collected by filtration, washed with water and dried to give the title compound. 1H NMR (CDCl): 7.26-7.82 (m, 6H), 4.26 (s, 3H); LC/MS (M+1)=203.29; RT=1.54 min
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