Diarylpyrazole formation

With regard to the synthesis of celecoxib (1), several routes were described in the 1995 patent by G. D. Searle As shown in Scheme 1, dione 7 was prepared by the Claisen condensation of 4-methylacetophenone with ethyl trifluoroacetate in the presence of NaOMe in methanol under reflux. Subsequent diarylpyrazole formation from the condensation of dione 7 and 4-sulfonamidophenylhydrazine hydrochloride then delivered... 

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