N-Oxides of the quinoxaline series. VI. N-Oxides of amino and hydroxy derivatives of quinoxaline was written by Elina, A. S.;Tsirul’nikova, L. G.. And the article was included in Zhurnal Obshchei Khimii in 1963.HPLC of Formula: 5424-05-5 This article mentions the following:
2-Acetamidoquinoxaline in 10.3% AcO2H in the presence of NaOAc (22 h. at 45-8掳) gave 50% 1,4-di-N-oxide, decomposed 233掳, and 4.5% more soluble 2-amino-3-hydroxyquinoxaline 1,4-di-N-oxide (Ia), decomposed 300掳. Reaction with AcO2H (48 h. at 20-5掳) gave 20% 2-acetamidoquinoxaline 1-N-oxide, m. 193-4掳, and 6% corresponding 4-N-oxide, m. 239-40掳, insoluble in CHCl3; the residue contained a mixture of these oxides. Heating 2-acetamidoquinoxaline in AcOH with 30% H2O2 in the presence of Na4P2O7 22 h. at 55-60掳 gave 20% Ia and mixed mono-N-oxides. 2-Amino-3-methylquinoxaline refluxed with Ac2O 0.5 h. gave 65% diacetyl derivative (I), m. 87.5-8掳; similar reaction in MePh in 2 h. gave 85% 2-acetamido-3-methylquinoxaline, m. 145-6掳. I and 10% AcO2H in the presence of H2SO4 (22 h. at 50掳) gave on evaporation and treatment with MeOH-Et2O 25% 4-N-oxide, m. 208-9掳, identified as that of 2-acetamido-3-methylquinoxaline; the residue gave some mono-N-oxide of I, m. 144.5-6掳. 2-Acetamido-3-methylquinoxaline heated 22.5 h. in AcOH with 30% H2O2 at 60掳 gave 62.7% 2-amino-3-methylquinoxaline 1,4-di-N-oxide, decomposed 215-16掳. Heating the N-oxides of 2-acetamidoquinoxalines with 2.5N HCl 10-12 min. at 100掳 gave: 2-aminoquinoxaline 1,4-di-N-oxide (II), decomposed 242掳, 89.5%, which gave a green color with FeCl3; 2-aminoquinoxaline 1-N-oxide (IIa), m. 191-2掳, 75.9%, bluegreen color with FeCl3; 2-aminoquinoxaline 4-N-oxide (IIb), decomposed 276掳, 70.3%, gave no color with FeCl3; 2-aminoquinoxaline 4-N-oxide (IIb) decomposed 276掳, 70.3%, gave no color with FeCl3; 2-amino-3-methylquinoxaline 4-N-oxide, m. 208-9掳, 80.2%, gave no color with FeCl3. Longer heating with 2.5N HCl resulted in isomerization of N oxides into o-hydroxy compounds and 2-10 h. heating gave the following from the above oxides: II gave in 0.5 h. mainly 2-amino-3-hydroxyquinoxaline 1-N-oxide (III), decomposed 300掳, and 10% 2,3-dihydroxyquinoxaline, did not m. <360掳; the former gave green color with FeCl3; similar reaction in 10 h. gave 2,3-dihydroxyquinoxaline 1-N-oxide (IV), decomposed 279-80掳, which gave red color with FeCl3. III in 4 h. gave IV. IIa in 13.5 h. gave 30% IIa.HCl, decomposed 241.5掳, and unchanged IIa. IIb in 2 h. gave mainly 2-amino-3-hydroxyquinoxaline, did not m. <360掳, and 20% 2,3-dihydroxyquinoxaline, did not m. <360掳, 2-amino-3-hydroxy-quinoxaline 1,4-di-N-oxide in 4 h. gave 65% 2,3-dihydroxyquinoxaline 1,4-di-N-oxide, decomposed 261-2.5掳. The Rf values for paper chromatog. of the oxides in BuOH-5% AcOH system are tabulated. II refluxed 0.5 h. in N NaOH gave (on acidification to pH 5) 55% III; IIa in 4 h. gave 65% 2-hydroxyquinoxaline 1-N-oxide (V), m. 207-8掳; mixed 1- and 4-N-oxides of 2-acetamidoquinoxaline in 0.5 h. gave mainly V and IIa, with some IIb; similarly, 2-amino-3-methylquinoxaline 1,4-di-N-oxide gave in 5.5 h. 30% 2-hydroxy-3-methylquinoxaline 1,4- di-N-oxide, decomposed 216-17掳, and unchanged starting material. Shaking the N-oxides in H over Raney Ni at room temperature in aqueous MeOH or aqueous NaOH or EtOH-AcOH gave the following results: II gave 2-aminoquinoxaline, m. 150-1掳; 2-amino-3-hydroxyquinoxaline 1,4-di-N-oxide gave the 4-N-oxide, decomposed 282掳, and 2-amino-3-hydroxyquinoxaline. IV gave 2,3-dihydroxyquinoxaline, while IIa was largely unchanged and gave some unidentified product (undescribed). In the experiment, the researchers used many compounds, for example, Quinoxalin-2-amine (cas: 5424-05-5HPLC of Formula: 5424-05-5).
Quinoxalin-2-amine (cas: 5424-05-5) belongs to quinoxaline derivatives. Condensed heterocycles of quinoxalines have become attractive targets in synthetic and medicinal chemistry due to their significant biological activities. They are well-known for application in organic light emitting devices, polymers and pharmaceutical agents. The quinoxaline-containing polymers are applicable in optical devices due to their thermal stability and low band gap.HPLC of Formula: 5424-05-5
Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider