In 1923,King, Harold; Murch, Wm. O. published 《Bromination of glyoxaline-4-carboxanilide》.Journal of the Chemical Society, Transactions published the findings.SDS of cas: 16681-56-4 The information in the text is summarized as follows:
The object of this investigation was the preparation of 4-bromoglyoxaline-5-carboxylic acid (I) with the view of synthesizing xanthine by condensation of the ester with CO(NH2)2. The acid was obtained but the small yields have prevented attempts at the condensation. Two mols. Br react with glyoxaline-4-carboxanilide in glacial AcOH, giving a mixture of mono-, di- and tri-Br derivatives This is extracted with H2O on the boiling H2O bath. The aqueous solution deposits glyoxaline-4-carbox-p-bromoanilide, crystallizing from AcOH with 2 AcOH of crystallization, lost at 100° and then m. 273-4°. Hydrolysis gives I. 5-Bromoglyoxaline-4-carbox-p-bromoanilide (II), m. 245-6°, is then extracted with very dilute HCl. The residue is the 2,5-dibromo derivative (III), C10H6ON3Br3, which crystallines with 1 C2H4O2, and m. 257-8° (decomposition). Hydrolysis of III with HCl (sealed tube at 150° for 3 hrs.) gave p-BrC6H4NH2, and a mixture containing about 95% dichloro- and 5% dibromoglyoxaline, m. 184-5°. Hydrolysis of III with HBr gave a mixture of the 2,5-Br2 derivative and 2-bromoglyoxaline, m. 207°; Pauly’s reagent gives a deep orange color; picrate, yellow, m. 232° (decomposition); nitrate, decomposes violently 137°. 2,5-Dibromoglyoxaline nitrate-silver nitrate, 2C3H2N2Br2.AgNO3.HNO3. II is soluble in about 6 parts boiling AcOH. It is mixed with a very small amount of a compound containing about 50% Br and m. 247°. Hydrolysis of II with 24% HBr gives p-BrC6H4NH2 and 5-bromoglyoxaline-4-carboxylic acid, m. 265°, soluble in 50 parts boiling H2O, and forms a hydrochloride, nitrate, Ag salt, and gives a deep orange color with Pauly’s reagent. Et ester, m. 170-1°. With 30% HBr some 4-bromoglyoxaline was also isolated. Bromination of II gave III with some of the compound m. 247°. The results came from multiple reactions, including the reaction of 2-Bromo-1H-imidazole(cas: 16681-56-4SDS of cas: 16681-56-4)
2-Bromo-1H-imidazole(cas: 16681-56-4) is a member of imidazole. Its exclusive structural characteristics with enviable electron-rich features are favorable for imidazole-based fused heterocycles to bind efficiently with an array of enzymes and receptors in biological systems through various weak interactions like hydrogen bonds, ion-dipole, cation-π, π-π stacking, coordination, Van der Waals forces, hydrophobic effects, etc., and therefore they demonstrate widespread bioactivities. SDS of cas: 16681-56-4
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem