The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《Quinoline-5,8-quinones》. Authors are Petrow, Vladimir; Sturgeon, Bennett.The article about the compound:8-Hydroxyquinoline 1-oxidecas:1127-45-3,SMILESS:OC1=CC=CC2=CC=C[N+]([O-])=C12).Computed Properties of C9H7NO2. Through the article, more information about this compound (cas:1127-45-3) is conveyed.
5-Amino-8-hydroxyquinoline sulfate (1 g.) in 10 mL. 10% H2SO4 and Na2Cr2O7 in H2O, the whole extracted with CHCl3, the CHCl3 extracts concentrated and the residue diluted with petr. ether gave 0.35 g. quinoline-5,8-quinone, light yellow needles, m. 129° (decomposition). 8-Hydroxy-5-nitrosoquinaldine (5.8 g.) in 100 mL. H2O and 6.3 g. NaOH treated with about 13 g. Na2S2O4 (I) and neutralized with AcOH gave 5-amino-8-hydroxyquinaldine (II); II as above gave 2 g. quinaldine-5,8-quinone, yellow-green prisms, m. 145° (decomposition) (from EtOH-petr. ether). Similarly 8-hydroxy-5-nitroso-7-methylquinoline gave the amine (III), yellow prisms, m. 155° (decomposition) (from C6H6), and III gave the quinone, light yellow needles, m. 181-2° (from EtOH-petr. ether). A solution of PhN2Cl (from 7 g. PhNH2.HCl and 4 g. NaNO2) added during 20 min. at 0-3° to 8.5 g. 5-amino-O-methylquinoline in 50 mL. AcOH, 200 mL. H2O, and 25 g. AcONa gave 9 g. 5-amino-6-methyl-8-phenylazoquinoline-HCl (IV), red-brown plates, m. 216° (from EtOH-petr. ether). IV (12 g.), 60 cc. concentrated HCl, 50 mL. H2O, and 150 mL. EtOH refluxed 2.5 h. gave 7 g. HCl salt, m. 212° (from EtOH), of the 5-HO analog (V), fine red needles m. 177° (from EtOH). V (1.5 g.) in EtOH, Pd-C, and H gave 0.5 g. 8-amino-5-hydroxy-6-methylquinoline (VI), pale brown plates, m. 216° (from EtOH). VI gave 6-methylquinoline-5,8-quinone, yellow needles, m. 188° (from CHCl3-petr. ether). 2,6-Dimethylquinoline (3.0 g.) in 8,5 mL. cold concentrated H2SO4, treated with 1.5 mL. concentrated HNO3 in 2.0 mL. concentrated H2SO4 2 h. on the steam bath, and the whole poured into cold dilute aqueous NH3 gave 3.8 g. 2,6-dimethyl-5-nitroquinoline (VII), pale yellow prisms, m. 106° (from pert. ether). VII (2.5 g.), 25 mL. 80% EtOH, 1 mL. concentrated HCl, and 6 g. reduced Fe gave 2.0 g. 5-amino analog (VIII), green needles, m. 190° (from C6H6-petr. ether), and VIII as above gave 60% 2,6-dimethylquinoline-5,8-quinone (IX), yellow plates, m. 150°, also obtained via 5-amino-2,6-dimethyl-8-phenylazoquinoline-HCl, red plates with green reflex, m. 210°, and 5-hydroxy-2,6-dimethyl-8-phenylazoquinoline, dark red fluffy needles, m. 168° (from EtOH), and 8-amino-5-hydroxy-2,6-dimethylquinoline (X) (X was very sensitive to air oxidation and was used directly without purification). Finely powd. 8-hydroxy-5-nitrosoquinoline (3 g.) added to 9 mL. concentrated HNO3 and 6 mL. H2O and kept 1.25 h. at 17° gave a precipitate of 8-hydroxy-5-nitroquinoline-HNO3; the whole cooled to 0° made alk. with cold KOH solution, and the red K salt decomposed with AcOH gave 2.9 g. 8-hydroxy-5-nitroquinoline, yellow needles, m. 180° (from EtOH). Similarly, 8-hydroxy-5-nitrosoquinaldine gave 8-hydroxy-5-nitroquinaldine, silky yellow needles, m. 136° (from C6H6-petr. ether) (a small amount of 8-hydroxy-5,7-dinitroquinaldine, small yellow needles, m. above 300° was a byproduct). The following compounds were prepared by this general procedure: To 1 g. nitro compound in 300 mL. H2O and 0.9 g. KOH was added 1 mol. equivalent Br or iodine dissolved in KBr or KI, resp., and the whole stirred at room temperature 2 h. and acidified, giving 60-70% yield of the halogenated product (all derivatives recrystallized from EtOCH2CH2OH): 7-bromo-8-hydroxy-5-nitroquinoline (XI), red felted needles, m. 200°; 7-bromo-8-hydroxy-5-nitroquinaldine (XII), red plates, m. 265° (decomposition); and 8-hydroxy-7-iodo-5-nitroquinaldine (XIII), bright red plates, m. 244°. As above, with I, XI gave the amino compound (XIV), light brown needles, m. 184° (decomposition) (from EtOAc-petr. ether); XII gave the amino compound (XV), golden brown needles, m. 176° (decomposition); and XIII gave the amino compound (XVI), yellow needles, m. 162° (decomposition from Et2O-petr. ether). As above, with Na2Cr2O7 were prepared the following 5,8-quinones (all recrystallized from CHCl3-petr. ether): 7-bromoquinoline (from XIV), pale yellow needles, m. 182°; 7-bromoquinaldine (from XV), orange-yellow needles, m. 178°; 7-iodoquinoline (from XVI), unstable yellow-brown needles, m. 160° (decomposition); and 7-iodoquinaldine, yellow-brown needles, m. 160° (decomposition). 4-IC6H4NH2 (XVII) (42 g.), 70 g. dry glycerol, and 33 g. As2O5 heated to 120° 20 mL. concentrated H2SO4 added dropwise with stirring, and with the temperature kept at 120° the whole refluxed 4 h., 600 mL. H2O added, the mixture filtered, the filtrate made alk. with aqueous NH3, extracted with C6H6, the C6H6 extracts extracted with 6N HCl, the base liberated from the HCl extracts with NaOH, extracted with CHCl3 and the CHCl3 extracts concentrated and distilled gave 6-iodoquinoline (XVIII), b1 120° pale yellow prisms, m. 88° (from petr. ether). XVIII (1.5 g.), 4.5 mL. concentrated H2SO4, and 0.8 mL. concentrated HNO3 in 1 mL. concentrated H2SO4 heated 1 h. at 100° gave 1.5 g. 6-iodo-5-nitroquinoline, m. 163° (from C6H6). XVII (25 g.), 20 mL. concentrated HCl, and 20 mL. paraldehyde kept overnight, the whole refluxed 2 h., H2O added, the aqueous solution decanted from the resin (XIX), the XIX extracted twice with 2N HCl, the combined HCl solutions treated as above m the preparation of XVIII gave 5.9 g. 6-iodoquinaldine (XX), prisms, m. 112° (from petr. ether). As above XX gave 90% 6-iodo-5-nitroquinaldine (XXI), pale yellow needles, m. 146 ° (from EtOH). XXI (5 g.) and 25 g. PhNH2 heated 2 h. at 180°, AcONa solution added, the excess PhNH2 steam distilled, the residue extracted with C6H6, the C6H6 extracts percolated through Al2O3, and the C6H6 evaporated gave 6-anilino-5-nitroquinaldine, felted orange needles, m. 147-8° (from EtOH). XXI (2.5 g.), 7 g. reduced Fe, 20 mL. EtOH, and 5 drops concentrated HCl refluxed 2 h., the whole filtered, and the filtrate made alk. with aqueous NH3 gave 2 g. 5-amino-6-iodoquinaldine, golden plates, m. 206° (decomposition) (from C6H6-petr. ether). 8-Hydroxyquinoline (2 g.) in CHCl3 and 2 mol ethereal peroxyphthalic acid in Et2O kept overnight, the whole evaporated to dryness, and the residue triturated with aqueous NH3 gave 8-hydroxyquinoline N-oxide (XXII), golden yellow needles, m. 138°. XXII (3.2 g. in 400 mL. 0.2% NaOH and 5.1 g. iodine in KI gave 8-hydroxy-5(?)-iodoquinoline N-oxide, yellow needles, m. 169° (from C6H6). XXII (1.6 g.) in 10 mL. AcOH and 1 mL. concentrated HNO3 kept 1 h. at 20° gave a precipitate of the nitrate which, decomposed with KOH, yielded 8-hydroxy-5(?)-nitroquinoline N-oxide (XXIII), light brown powder, m. 217-18° (decomposition) (from alc.). XXIII and I as above gave the amine, orange-red needles, m. 213° (decomposition) (from C6H6). Quinoline-5,8-quinone (0.75 g.), 1.2 g. PhNH2, and 10 mL. EtOH refluxed 1 h. and the whole poured into dilute AcOH gave 6(7)-anilinoquinoline-5,8-quinone, scarlet needles, m. 213° (decomposition) (from C6H6petr. ether). 7-Bromoquinoline-5,8-quinone (0.1 g.), 0.053 g. PhNH2.HCl, 0.05 g. AcONa, and 5 mL. alc. refluxed 2 h., and the whole poured into H2O gave 0.1 g. 6-anilino-7-bromoquinoline-5,8-quinone, dark red prisms, m. 189° (decomposition). 8-Hydroxy-5-nitroquinoline (2 g.) in 20 mL. boiling EtOH with 2 mL. 36% HCHO and 2 mL. morpholine gave 2.3 g. 8-hydroxy-7-morpholinomethyl-5-nitroquinoline, yellow prisms (which rapidly discolor), m. 112° (decomposition).
From this literature《Quinoline-5,8-quinones》,we know some information about this compound(1127-45-3)Computed Properties of C9H7NO2, but this is not all information, there are many literatures related to this compound(1127-45-3).
Reference:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider