C(O[CH:4](OCC)[CH2:5][NH:6][C:7]([C:9]1[CH:13]=[C:12]([C:14]2[CH:19]=[CH:18][C:17]([Cl:20])=[CH:16][CH:15]=2)[N:11]([C:21]2[CH:26]=[CH:25][C:24]([Cl:27])=[CH:23][C:22]=2[Cl:28])[N:10]=1)=[O:8])C.O.[C:33]1([CH3:43])[CH:38]=[CH:37][C:36](S(O)(=O)=O)=[CH:35][CH:34]=1>C1(C)C=CC=CC=1>[CH2:43]([N:6]1[CH:5]=[CH:4][C:13]2=[C:12]([C:14]3[CH:15]=[CH:16][C:17]([Cl:20])=[CH:18][CH:19]=3)[N:11]([C:21]3[CH:26]=[CH:25][C:24]([Cl:27])=[CH:23][C:22]=3[Cl:28])[N:10]=[C:9]2[C:7]1=[O:8])[C:33]1[CH:38]=[CH:37][CH:36]=[CH:35][CH:34]=1A mixture of 5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-1H-pyrazole-3-carboxylic acid (2,2-diethoxyethyl)-amide (I-1A-1a; 528 mg, 0.92 mmol) and p-toluenesulfonic acid monohydrate (175 mg, 0.92 mmol) in toluene (5 ml) was heated to reflux in round bottom flask fitted with a Dean-Stark condenser. After 1 hour, the reaction was cooled to room temperature, and then extracted from saturated aqueous sodium bicarbonate with ethyl acetate. The combined organic layers were washed with brine, dried (MgSO4), a concentrated, in vacuo. The crude material (0.49 g) was purified on a Biotage™ Flash 40S column using 10-20-40% ethyl acetate in hexanes as eluant to afford I-1A-1b as a solid (69 mg, 16%): +ES MS (M+1) 480.1; 1H NMR (500 MHz, CD2Cl2) δ 7.50 (d, J=1.5 Hz, 1H), 7.48 (d, J=8.3 Hz, 1H), 7.42 (dd, J=8.3, 2.1 Hz, 1H), 7.38-7.27 (m, 7H), 7.18 (d, J=8.7 Hz, 2H), 6.95 (d, J=7.5 Hz, 1H), 6.42 (d, J=7.5 Hz, 1H), 5.21 (s, 2H).
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