4-Amino-2,3-difluoro-5-nitro-benzoic acid methyl ester 4 (0.50 g, 2.15 mmol) is suspended in xylenes (3 mL) and 2-methyl-4-trifluoromethoxy-phenylamine (1.00 g, 5.23 mmol) is added. The reaction mixture is stirred at 140° C. under N2. After stirring for 7 days, the reaction is a mixture of starting material and product. The reaction mixture is cooled to room temperature. The reaction mixture is poured into a separatory funnel and diethyl ether and 10% aqueous HCl are added and the layers separated. The aqueous phase is extracted with three portions of diethyl ether. The combined diethyl ether layers are dried (MgSO4) and concentrated under reduced pressure. The residue is redissolved in methylene chloride and flushed through a plug of silica gel eluting with methylene chloride. The filtrate is concentrated under reduced pressure to give a bright yellow solid. The solid is washed with diethyl ether and the filtrate is concentrated under reduced pressure and the residue is further purified by FCC (eluting with 100% methylene chloride) to yield 0.39 g (45%) of the desired pure product as a yellow solid. MS APCI (−) m/z 402 (M−1) detected.
