OC1C=CC=CN=1.[Cl:8][C:9]1[CH:31]=[CH:30][C:12]([C:13]([C:15]2[C:16]([C:25]([O:27][CH2:28][CH3:29])=[O:26])=[N:17][NH:18][C:19]=2[C:20]([O:22]CC)=O)=[O:14])=[C:11]([NH2:32])[CH:10]=1>C1(C)C=CC=CC=1>[Cl:8][C:9]1[CH:31]=[CH:30][C:12]2[C:13](=[O:14])[C:15]3[C:16]([C:25]([O:27][CH2:28][CH3:29])=[O:26])=[N:17][NH:18][C:19]=3[C:20](=[O:22])[NH:32][C:11]=2[CH:10]=1To a solution of 2-hydroxypyridine (1.30 g, 13.69 mmol) in toluene (400 mL) was added diethyl 4-(4-chloro-2-amino-benzoyl)-1H-pyrazole-3,5-dicarboxylate (5 g, 13.69 mmol). The mixture was refluxed for 2 days and then the solvent was distilled off and the residual solid was heated at 171-172° C. for 4 days. The solid was allowed to cool and was continuously chromatographed eluting for 2 hours with dichloromethane to remove starting material. The remaining material on the column was eluted with chloroform:2-propanol (97:3) for 4 days. After each day the solvent in the receiving flask was replaced with fresh solvent. Filtering the solvent from the first two receiving flasks gave the title compound as a white solid (1.65 g, 38%, mp 290° C.). Alternatively, the title compound can preferably be removed from the column by elution with ethanol/chloroform (7:93).
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