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Next, the 2-phenyl-5-thiophen-2-yl-2H-pyrazol-3-ylamine, compound obtained above, (315 mg, 1.30 mmol) was dissolved in pyridine (3 mL) and 4-ethylbenzene sulfonyl chloride (211 muL, 1.30 mmol) added to the reaction vessel. The reaction mixture was stirred at room temperature for 1 hour followed by heating at 60 C. for 16 hours. After this period, the reaction mixture was concentrated in vacuo and the residue was redissolved in ethyl acetate and the organic solution washed with water, saturated aqueous NaHCO3 and brine, respectively. The organic layer was dried over anhydrous Na2SO4, concentrated onto silica gel and purified by flash chromatography (0-30% ethyl acetate/hexanes gradient). The fractions were concentrated. The crude material was purified by reverse phase HPLC. The fractions were lyophilized, redissolved in ethyl acetate and washed with saturated aqueous NaHCO3. The organic layer was dried over anhydrous Na2SO4 and concentrated to afford the title compound (90 mg). LC/MS: Calc. C21H19N3O2S2 409.09 amu Obs. [M+H]+=410.1 amu.