3-Bromo-5-nitrobenzoicacid

white to slightly yellow crystalline needles

To a solution of 3-amino-5-nitro-benzoic acid (17.6 g, 96.6 mmol, 1 equiv) in 48percent aqueous HBr solution (180 ML) at 0°C was added portionwise NANO2 (8.67 g, 126 MMOL, 1.3 equiv) over 20 min. The temperature was kept BELOW 8 C during this addition. The resulting mixture was then added to a suspension of CuBr (9.7 g, 67.6 mmol, 0.7 equiv) in 48percent aqueous HBr solution (50 ml) at 65 C over 40 min. The temperature was kept above 60C during the addition. The resulting mixture was stirred at 70 C for 45 min, cooled to room temperature and diluted with 1L of water. The aqueous phase was extracted three times with Et20. The combined organic layers were washed twice with H2O, dried over MGS04 and concentrated in vacuo to give 3-bromo-5-nitro-benzoic acid (D5) (21 g, 88percent) as a brown solid. [M-H]-= 245.7, RT = 2.82 minTo the solution of 7.92 g (43 mmol) 3-amino-5-nitro-benzoic acid in 4 ml water in an ice bath 48.8 ml (434 mmol, 10 eq) of aqueous 48percent HBr are added. A saturated aqueous solution of 4.05 g (59 mmol, 1.35 eq) sodium nitrite is added over 10 min. The obtained solution is added to the solution of 9.36 g (65 mmol, 1.5 eq) copper bromide in 48.8 ml (434 mmol, 10 eq) of aqueous 48percent HBr at 70° C. The mixture is heated for 45 min at 70° C. After cooling to rt diethylether is added and the organic layer is washed with water until neutral pH is reached. Drying over sodium sulfate and evaporation of the solvent at reduced pressure gives 9.14 g (37 mmol, 86percent) product as yellow solid.MS (ES-): 245/247=[M+H]Part G: A solution of 3-nitrobenzoic acid (16.7 g, 100 mmol) in trifluoroacetic acid (50 mL) and sulfuric acid (20 mL) was stirred at 50° C., and N-bromosuccinimide (26.7 g, 150 mmol) was added in three portions over 3 hours. The mixture was stirred for 16 hours and then cooled to room temperature. The mixture was then poured into ice water (200 mL) and extracted three times with ethyl acetate. The organic layers were combined, dried over sodium sulfate and concentrated under vacuum. The residue was recrystallized from dichloromethane to provide a white solid (17.7 g, 72percent). A mixture of 3-nitrobenzoic acid (10 g, 0.06 mols), concentrated sulphuric acid (120ml), silver sulphate (9.33 g, 0.03 mols) and bromine (3.68 ml, 0.07 mols) was stirred at 100°C for 6h. The mixture was poured on ice, and the solid filtered off and extracted with sodium carbonate solution. The title compound was precipitated on acidification from dilute alcohol giving 7.11 g (47percent). HPLC/MS (10 min) retention time 5.69 min LRMS: m/z 244 (M-1)PREPARATION 20

Molecular Weight:246.01
XLogP3:2.3
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