4-Bromo-3-nitrobenzoicacid

light yellow powder

p-Brombenzoic acid (8, 5.00 g, 24.9 mmol) was slowly added in portions to a cold mixture (0 °C) of conc. nitric acid (6.2 mL, 0.15 mmol) and conc. sulfuric acid (15.2 mL, 300 mmol). The addition was performed in such a way that the temperature did not exceed 5 °C. After stirring for 3 h at 0 °C and 2 h at room temp., the mixture was poured on ice-containing water. The resulting colourless solid was filtered off and washed extensively with water. Yield: 6.00 g (24.4 mmol, 98percent) (ref.[2]: 96percent), m. p. 202 °C. 1H NMR (200 MHz, DMSO-d6): δ = 8.46 – 8.42 (m, 1H, Ar-H-2), 8.09–8.05 (m, 2H, Ar-H-5, 6) ppm. 13C NMR (50 MHz, DMSO-d6): δ = 165.0 (s, CO2H), 149.7 (s, Ar-C-3), 135.4 (d, Ar-C-6), 132.4 (d, Ar-C-5), 131.7 (s, ArC-1), 125.9 (d, Ar-C-2), 118.0 (Ar-C-4) ppm. MS (EI, 70 eV): m/z = 245/247 (95/100) [M]+·. MS (CI, isobutane): m/z = 246/248 (100/99) [M + H]+. IR (ATR): ν = 3082 (arylH), 2820 (br., OH), 1684 (C=O), 1595 (arom. C=C), 1530, 1303 (NO2), 1034 (aryl-Br), 907, 809 (1, 2, 4-trisubst. aryl) cm-1Example 65; 4-Bromo-3-nitrobenzoic acid (43) (Scheme 9); Fuming nitric acid (12.4 mL, 0.3 mol) was slowly added to conc. sulfuric acid (30.1 mL, 0.6 mol) at 0-5° C. The cooled nitrating mixture was taken in a beaker equipped with a mechanical stirrer and addition funnel. 4-Bromotoluic acid 42 (40 g, 0.2 mol) was added to this mixture in small portions over 5 hours at such a rate to maintain the temperature at 0-5° C. The reaction mixture was stirred further for additional 2 h at room temperature and then poured over ice. The solid that separated was filtered, washed with water till it was free of acid and then air dried to constant weight to give the pure compound 43. White solid (47.2 g, 96percent). A 200 mL flask was charged with 4-bromobenzoic acid (9.84 g, 49.0 mmol), nitric acid (70percent, 90 mL) and fuming nitric acid (90percent, 70 mL), fitted with a reflux condenser and the resulting suspension was stirred under reflux overnight. The homogeneous yellow solution obtained was cooled to 0 °C, filtered and the solid washed with cold water (100 mL) to yield a white powder. Recrystallization from methanol/water afforded the product (10.82 g, 44.0 mmol, 90percent) as a microcrystalline white powder. ‘H NMR (400 MHz, DMSO-d6) 13.74 (bs, 1H), 8.39 (s, 1H), 8.09—7.94 (m, 2H). ‘3C NMR (100 MHz, DMSO-d6) 165.0, 149.6, 135.4, 133.8, 131.7, 126.0, 118.2.4-bromo-3-nitrobenzoic acid (1): IN AS 1 L flask, 4-bromobenzoic acid (50.0 g, 0.25 mol, Aldrich Co. ), nitric acid (450 mL) and fuming nitric acid (100 mL) were mixed and refluxed for 24 h. The mixture was cooled at 0°C and the white precipitate filtered through a Buecher funnel, washed thoroughly with water and dried under reduced pressure to provide 53.9 g of the title product as a white solid. M. P.: 202-204°C (Yield : 88percent). 1H NMR (300 MHz, Acetone-d6, ppm): 11.37 (s, 1H) ; 8.47 (d, 1H, J= 1. 9 HZ) ; 8.16 (dd, 1H, J= 6.6 and 1.6 Hz); 8.04 (d, 1H, J= 8.3 Hz). 13C NMR (75 MHz, Acetone-d6, ppm): 206.35 ; 165.07 ; 136.29 ; 134.55 ; 132.26 ; 126.90 ; 119.08.Reference Example 34

Molecular Weight:246.01
XLogP3:2.5
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:1
Exact Mass:244.93237
Monoisotopic Mass:244.93237
Topological Polar Surface Area:83.1
Heavy Atom Count:13
Complexity:227
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes