Justoni, R.; Pessina, R. published the artcile< Substances presumably with antitubercular action. I. Derivatives of 4-aminosalicylic acid acylated at the hydroxyl group>, COA of Formula: C7H4BrNO4, the main research area is .
Treating p-O2NC6H4Me with Br in the presence of Fe powder, washing with NaHSO3 solution, steam distillation, and crystallization from EtOH give 90% 2,4-Br(O2N)C6H3Me (I). Heat 5 kg. of I with 35 l. 65% HNO3 to the b.p. for 96 hrs., with 11.72% HNO3 added every 6 hrs., cool to -10°, sep. the acid liquid to treat another quantity of 5 kg. I, dilute the part in excess of 35 l., and distil to recover the unreacted I in the distillate and some of the Br(O2N)C6H3CO2H (II) in the residue; combine this residue with the bulk of II, dissolve in NH3, and precipitate with acid. The yield of II is 65%. II (2.46 kg.) in 4 l. H2O is mixed with 1 l. of 36° Bé. NaOH, heated 3 hrs. with 360 g. Cu(OAc)2 and 1.86 kg. Ba(OH)2.8H2O with further addition of 3 portions of 600 g. Ba(OH)2.8H2O, and the filtered paste of Ba p-nitrosalicylate treated with HCl to give the free acid (III). Acetylation gives 2,4-AcO(O2N)C6H3CO2H, m. 156°. Heating III with EtCOCl in PhMe gives 4,2-O2N(EtCO)C6H3CO2H, m. 153-4°. O-PrCO homolog, m. 134-5°; O-Me2CHCO homolog, m. 145-6°. The NO2 group is reduced at 20-5° with Pt black as a catalyst and the Me or Et ester of the acylated acid as solvent. 4,2-H2N(AcO)C6H3CO2H m. 136°. Further acetylation gives the N,O-di-Ac derivative, m. 189-90°. The O-EtCO acid m. 147°; O-PrCO acid m. 133°; O-Me2CHCO acid m. 150° (decomposition). Heating 2,4-HO(O2N)C6H3CO2Me with Ac2O gives 4,2-O2N(AcO)C6H3CO2Me, m. 79-80° (from petr. ether); iso-Pr ester, m. 44-5°. 4,2-O2N(AcO)C6H3CO2Me in 80% AcOH with Zn slowly forms 4,2-H2N(AcO)C6H3CO2Me, m. 109-10°; the O-EtCO homolog m. 111-12°. 4,2-H2N(AcO)C6H3CO2CHMe2 m. 141-2°; O-Me2CCO homolog m. 99-101°.
Farmaco (1946-1952) published new progress about Dyes. 16426-64-5 belongs to class bromides-buliding-blocks, and the molecular formula is C7H4BrNO4, COA of Formula: C7H4BrNO4.
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary