6-Methoxyquinoxaline (cas: 6639-82-3) belongs to quinoxaline derivatives. Quinoxaline derivatives are important constituents of pharmacologically active compounds, including antibacterial, antibiotic and antineoplastic, antifungal, anti-inflammatory and analgesic drugs. The parent substance of the group, quinoxaline, results when glyoxal is condensed with 1,2-diaminobenzene. Substituted derivatives arise when α-ketonic acids, α-chlorketones, α-aldehyde alcohols and α-ketone alcohols are used in place of diketones.Product Details of 6639-82-3
Nitration of quinoxalines was written by Otomasu, Hirotaka;Nakajima, Shoichi. And the article was included in Chemical & Pharmaceutical Bulletin in 1958.Product Details of 6639-82-3 This article mentions the following:
Quinoxaline (I), its N-oxide, and its 2,3-Me2 derivative resisted nitration even with concentrated H2SO4 and fuming HNO3 (d. 1.52) at 100°. The presence of polar substituents in either ring facilitated nitration. The 6-MeO derivative (II) of I (0.43 g.) in 4 cc. concentrated H2SO4 at 0°, well stirred during the addition of 0.5 g. powd. KNO3, the mixture kept 2 hrs. at room temperature, and poured on ice yielded 0.45 g. 5,6-O2N(MeO) derivative (III) of I, m. 203° (Me2CO), and this catalytically reduced (10% Pd-C) in MeOH gave the 5,6-H2N(MeO) derivative (IV) of I, m. 96° (ligroine). The position of the NO2 group in III was confirmed by the synthesis of IV from 4,2,3-H2N(O2N)2C6H2OMe (V). V (5 g.) catalytically reduced (Pd-C) to 2,3,4-(H2N)3C6H2OMe, and this under H warmed 30 min. with 10 g. glyoxal bisulfite in 200 cc. hot H2O, the mixture refluxed 1.5 hrs. on a water bath, evaporated in vacuo, made alk. with NaOH, and the resulting solid extracted with CHCl3 yielded 1.2 g. IV, identical with the sample from III. No isomeric 5,8-H2N(MeO) derivative (VI) of I was produced in this reaction. However, 4 g. 4,2,3-AcNH(O2N)2C6H2OMe in place of V similarly reduced and condensed with (CHO)2 yielded 1.8 g. 5,8-AcNH(MeO) derivative of I, m. 149°, hydrolyzed by warming 1 hr. on a water bath with 20% NaOH and extracting the cooled mixture with CHCl3 to give VI, m. 125° (C6H6). The 5-MeO derivative of I (0.5 g.) in 5 cc. concentrated H2SO4 warmed 15 min. at 60° with 1 g. KNO3 and the mixture poured into 80 cc. ice water yielded 0.6 g. 5,6,8-MeO(O2N)2 derivative of I, m. 204-6° (MeOH), and no mono-O2N derivative could be formed even at a lower temperature 3,2-Me(HO) derivative of I (5 g.) nitrated as was II yielded 5 g. 3,2,6-Me(HO)(O2N) derivative (VII) of I, m. 270° (Me2CO), but no nitration of the 2,3-Cl(Me) or 2,3-(EtO)Me derivatives of I took place under similar conditions. In an attempt to confirm the position of the NO2 group in VII by synthesis, 1.5 g. 3,4-(H2N)2C6H3NO2 (VIII) in 200 cc. MeOH was boiled 1 hr. with 1 g. AcCO2H and the MeOH evaporated to yield 1.85 g. 3,2,7-Me(HO)(O2N) derivative of I, m. 255° (MeOH), obviously different from VII. VII (1 g.) methylated with 4 cc. Me2SO4 in 20 cc. 20% NaOH yielded 0.55 g. 1,3-dimethyl-2-oxo-6-nitro-1,2-dihydroquinoxaline, m. 218° (Me2CO), formed also (0.16 g.) from 0.2 g. 2,4-H2N(O2N)C6H3NHMe in 50 cc. MeOH condensed as was VIII with 0.2 g. AcCO2H. This synthesis confirms the 6-position of NO2 in VII. In the experiment, the researchers used many compounds, for example, 6-Methoxyquinoxaline (cas: 6639-82-3Product Details of 6639-82-3).
6-Methoxyquinoxaline (cas: 6639-82-3) belongs to quinoxaline derivatives. Quinoxaline derivatives are important constituents of pharmacologically active compounds, including antibacterial, antibiotic and antineoplastic, antifungal, anti-inflammatory and analgesic drugs. The parent substance of the group, quinoxaline, results when glyoxal is condensed with 1,2-diaminobenzene. Substituted derivatives arise when α-ketonic acids, α-chlorketones, α-aldehyde alcohols and α-ketone alcohols are used in place of diketones.Product Details of 6639-82-3
Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider