Hydrochloric Acid → 5-Amino-4-[3-(2-aminosulfonylethenyl)benzoyl]-1-(4-fluorophenyl)pyrazole

Participants

Reaction Conditions

Reaction Steps

A mixture of 5-amino-4-(3-bromobenzoyl)-1-(4-fluorophenyl)pyrazole (1.5 g, 4.14 mmol) [prepared as described in Example 1 above], vinylsulfonamide (1.33 g, 12.4 mmol), bis(triphenylphosphine)palladium chloride (0.3 g, 0.42 mmol) and triethylamine (6 ml, 43 mmol) in dimethylformamide (18 ml) was heated at 100° C. under argon. After 16 h, the reaction mixture was cooled to room temperature and poured into 1 N hydrochloric acid. The product was extracted into ethyl acetate, washed with brine, dried over sodium sulfate and filtered. The organic layer was removed in vacuo and the residue was purified by flash chromatography (elution gradient: 40-80% ethyl acetate/hexane) to give 5-amino-4-[3-(2-aminosulfonylethenyl)benzoyl]-1-(4-fluorophenyl)pyrazole which was recrystallized from a mixture of methanol/ethyl acetate/hexane to give 0.78 g of the desired product.

Provenance & Evidence