Aniline → Methyl 4-amino-3-fluoro-5-nitro-2-(phenylamino)benzoate

Participants

Reaction Conditions

Reaction Steps

4-Amino-2,3-difluoro-5-nitro-benzoic acid methyl ester 4 (23.48 g, 101.1 mmol), the product of Example 1, Step C, is suspended in xylenes (125 mL) and aniline (92 mL, 1011 mmol) is added. The reaction mixture is stirred at 125° C. for 16 hours under N2. The reaction mixture is cooled to room temperature and solids precipitate out of solution. The solids are collected by filtration and are washed with xylenes and then diethyl ether. Recovered 22.22 g (72.78 mmol) of yellow solid which is pure desired product. The filtrate is concentrated under reduced pressure, redissolved in methylene chloride and flushed through a plug of silica gel eluting with methylene chloride. The desired fractions are concentrated under reduced pressure to give a brown solid which is triturated with diethyl ether to give 5.47 g (17.91 mmol) of yellow solid which is pure desired product. Combined product yield is 27.69 g (90%). MS APCI (−) m/z 304 (M−1) detected.

Provenance & Evidence