N[C:2]1[NH:3][N:4]([C:8]2[C:13]([Cl:14])=[CH:12][C:11]([Cl:15])=[CH:10][C:9]=2[Cl:16])[C:5](=[O:7])[CH:6]=1.[C:17](Cl)(=[O:20])[CH2:18][CH3:19].Cl.[OH-].[K+].[N:25]1C=CC=CC=1>O1CCCC1.CO.C(O)(=O)C>[O:7]=[C:5]1[N:4]([C:8]2[C:13]([Cl:14])=[CH:12][C:11]([Cl:15])=[CH:10][C:9]=2[Cl:16])[N:3]=[C:2]([CH:18]([CH3:19])[C:17]([NH2:25])=[O:20])[CH2:6]13-Amino-1-(2,4,6-trichlorophenyl)-5-pyrazolone (35.0 g, 125 mmole) was dissolved in dry tetrahydrofuran (350 ml) and pyridine (35 ml) and the solution was cooled in an ice-bath to 10° C. A solution of propionyl chloride (35.15 g, 0.18 mmole) in tetrahydrofuran (60 ml) was added dropwise keeping the temperature below 10° C. The mixture was stirred at room temperature for 48 hrs then it was poured into dilute hydrochloric acid (2.51). The resulting gum was extracted with ethyl acetate (700 ml) and the solution was washed with water and dried (MgSO4). Evaporation of the solvent under reduced pressure gave a light brown oil which was dissolved in methanol (120 ml). A solution of potassium hydroxide (70.0 g, 125 mmol) in methanol was added dropwise with stirring and the mixture was stirred for 0.5 hrs. Glacial acetic acid was added to the suspension and stirred for 2 hr. The buff colored solid was filtered off, washed with water and dried in a vacuum oven. The yield of product was 35.54 g, 85%.
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