5-Fluoro-3-methyl-2-nitro-benzoic acid synthesis

Yield:952479-96-8 77%

Reaction Conditions:

with sulfuric acid;potassium nitrate at 20; for 1 h;

Steps:

9.A

Step A: At 0 ⁰C, to 3-fluoro-5-methylbenzoic acid (8.0 g, 52 mmol) was added con. H₂SCM (OO ml) followed by KNO₃ (5.8 g, 57 mmol). The reaction solution was then warmed to ambient temperature and stirred for 1 h. The reaction mixture was poured into ice water to precipitate 5-fluoro-3-methyl-2-nitrobenzoic acid as a white solid after filtration (8.0 g, 77%): ¹H NMR (500 MHz, CDCl₃) δ 7.63 (dd, J= 8.0 Hz, 3.0 Hz, IH), 7.27 (dd, J= 8.0 Hz, 3.0 Hz, I H); MS (ESI+) m/z 200 (M+H).

References:

WO2011/8572,2011,A2 Location in patent:Page/Page column 68