C([O:3][C:4]([C:6]1[N:7]([CH3:20])[N:8]=[C:9]([C:12]2[C:17]([F:18])=[CH:16][C:15]([Cl:19])=[CH:14][N:13]=2)[C:10]=1[CH3:11])=[O:5])C.[OH-].[Na+].Cl>CS(C)=O>[Cl:19][C:15]1[CH:16]=[C:17]([F:18])[C:12]([C:9]2[C:10]([CH3:11])=[C:6]([C:4]([OH:5])=[O:3])[N:7]([CH3:20])[N:8]=2)=[N:13][CH:14]=16.75 g of 5-(5-chloro-3-fluoropyridin-2-yl)-2,4-dimethyl-[2H]-pyrazole-3-carboxylic acid ethyl ester are suspended in 40 ml of dimethyl sulfoxide. With occasional cooling in an ice-bath (internal temperature <30° C.), 14.3 ml of a 2N sodium hydroxide solution are added dropwise. The thick, yellowish-brown suspension is stirred at 22° C. for 2 hours. The suspension is then introduced into ice-water and adjusted to pH 1 with 2N hydrochloric acid. The resulting slurry is filtered, washed well with cold water and then dried in vacuo at 60° C. 5.97 g of the desired title compound are obtained in the form of a beige solid having a melting point of 194-196° C.
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