In general, if the atoms that make up the ring contain heteroatoms, such rings become heterocycles, and organic compounds containing heterocycles are called heterocyclic compounds. An article called Heterocyclic N-oxides. V. Substitution reactions on 8-hydroxyquinoline 1-oxide, published in 1968, which mentions a compound: 1127-45-3, Name is 8-Hydroxyquinoline 1-oxide, Molecular C9H7NO2, Recommanded Product: 1127-45-3.
Nitration and halogenation of 8-hydroxyquinoline 1-oxide (I) having N-oxide and phenolic OH groups, each capable of orienting electrophilic substitution in the different rings, was studied with a view to knowing the relative directive influence of these groups and to screen the compounds obtained for bacteriostatic and fungistatic activity. Halogenation afforded under usual conditions products by substitution only in the benzene ring. Thus, 1.5 ml. SO2Cl2 in 10 ml. CHCl3 was added dropwise to a stirred solution of 0.8 g. I in 10 ml. CHCl3 at <5° to yield 0.92 g. 5,7-dichloro-8-hydroxyquinoline 1-oxide (II) as H2O-insoluble fraction (aqueous solution A), m. 203-4° (HOAc). Deoxygenation of II with PCl3 afforded 5,7-dichloro-8-hydroxyquinoline, m. 176°. The aqueous solution (A) on cooling yielded 0.07 g. 5-chloro-8-hydroxyquinoline 1-oxide, m. 169-70°. Similarly, bromination of 0.8 g. I in 10 ml. HOAc with 1 ml. Br in 10 ml. HOAc yielded 1.42 g. of the dibromo compound, m. 198-200° (HOAc), which on deoxygenation yielded 5,7-dibromo-8-hydroxyquinoline, m. 195°. Nitration of 0.8 g. I in 10 ml. HOAc with 2 ml. fuming HNO3 (d. 1.5) initially at room temperature and then 1 hr. at 70-80° (water-bath) yielded 0.8 g. 5,7-dinitro-8-hydroxyquinoline 1-oxide (III), m. 213-14° (HOAc). Nitration of 0.8 g. I in 10 ml. HOAc with 0.7 ml. concentrated HNO3 (d. 1.42) at <20° for 1 hr. yielded 0.75 g. 5-nitro-8-hydroxyquinoline 1-oxide (IV), m. 191-3° (EtOH). The structure of III and IV were established through deoxygenation and comparison with the known 5-nitro and 5,7-dinitro-8-hydroxyquinolines. The phenolic hydroxyl exerts greater influence than the N-oxide function. The usual 5,7-disubstituted derivatives of 8-hydroxyquinoline, 5,7-dihalo- or the 5,7-dinitro compounds were resistant to N-oxidation either by 30% H2O2-HOAc or BzO2H. If you want to learn more about this compound(8-Hydroxyquinoline 1-oxide)Recommanded Product: 1127-45-3, you may wish to communicate with the author of the article,or consult the relevant literature related to this compound(1127-45-3).
Reference:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider