[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[S:12][C:11]([C:13]([O:15]CC)=[O:14])=[N:10][C:9]=2[C:18]2[CH:23]=[CH:22][C:21]([Cl:24])=[CH:20][C:19]=2[Cl:25])=[CH:4][CH:3]=1.[OH-].[K+].Cl>CO.O>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([C:8]2[S:12][C:11]([C:13]([OH:15])=[O:14])=[N:10][C:9]=2[C:18]2[CH:23]=[CH:22][C:21]([Cl:24])=[CH:20][C:19]=2[Cl:25])=[CH:6][CH:7]=1Part A: Ethyl 5-(4-bromophenyl)-4-(2,4-dichlorophenyl)thiazole-2-carboxylate (1.80 gram, 3.94 mmol) is dissolved in methanol (20 mL) and a solution of KOH (0.65 gram (85%), 9.85 mmol) in water (20 mL) is added. The resulting mixture is heated at reflux temperature for 1 hour, poured into water and acidified with hydrochloric acid (1N solution). The formed precipitated material is collected by filtration and dried in vacuo at room temperature to give a quantitative yield of 5-(4-bromophenyl)-4-(2,4-dichlorophenyl)-thiazole-2-carboxylic acid. Melting point: 94-95° C.
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