Synthesis
A. Synthesis of 2-fluoro-6-nitrobenzoic acid. Under stirring, 2-fluoro-6-nitrotoluene (exact amount not provided) was added to a suspension of potassium permanganate (102 g, 0.65 mol) in water (1.4 L). The reaction mixture was heated to reflux for 4 h, subsequently cooled to room temperature, filtered and washed with diethyl ether. The aqueous phase was acidified to pH 2 with concentrated hydrochloric acid and then extracted with ethyl acetate. The organic phase was washed with brine, dried over magnesium sulfate, filtered, and concentrated under vacuum to give 11.81 g (40% yield) of 2-fluoro-6-nitrobenzoic acid. The product was characterized by 1H NMR and IS-MS (m/e 184.0 [M-1]). Elemental analysis (C7H4FNO4) Calculated values: C, 45.42; H, 2.18; N, 7.57; Measured values: C, 45.22; H, 2.29; N, 7.27.
References
[1] Chemische Berichte, 1896, vol. 29, p. 841
[2] Journal of Medicinal Chemistry, 1994, vol. 37, # 6, p. 758 - 768
[3] Israel Journal of Chemistry, 1964, vol. 2, p. 25 - 28
[4] Patent: US6635657, 2003, B1
[5] Patent: US4316839, 1982, A
