Quinoxaline derivatives. V. Some reactions of 2-cyano-3-hydroxyquinoxaline 1-oxide was written by Ahmad, Yusuf;Habib, M. S.;Iqbal, M.;Ziauddin. And the article was included in Bulletin of the Chemical Society of Japan in 1965.SDS of cas: 1910-90-3 This article mentions the following:
As has been reported the title compound (I, R = H), with a CN group and a N-oxide side by side, has unusual properties (Pachter and Kloetzel, CA 47, 10542b) and was unchanged on refluxing with PCl3. Deoxygenation by reduction with Na dithionate in HOAc or EtOH, Zn and HCl, or catalytically with H over Pd-C was accompanied by loss of the CN group and gave in each case II (R = R1 = R2 = H). I refluxed with PhNH2 4 hrs., cooled, and diluted with petr. ether gave 90% II (R = R1 = H, R2 = NHPh), m. 247-8° (EtOH). Similarly with excess MeNHPh, I (R = H) gave 40% II (R = R1 = H, R2 = NMePh), m. 180-2° (EtOH), which was refluxed with Me2SO4 in the presence of anhydrous K2CO3 and Me2CO to give 50% II (R = H, R1 = Me, R2 = NMePh), m. 145-6°, the ir spectrum and mixed m.p. of which were identical with a sample prepared by the method of Clark-Lewis (CA 51, 10537g). Similarly, I (R = H) with cyclohexylamine gave 90% II (R = R1 = H, R2 = cyclohexylamino), m. 246° (EtOH). I (R = Cl) or I (R = EtO) with PhNH2 gave in good yield II (R = Cl, R1 = H, R2 = NHPh), m. 318-19° (glacial HOAc), or II (R = EtO, R1 = H, R2 = NHPh), m. 260-1° (EtOH), resp. I (R = H) or III refluxed in fuming HBr 2 hrs. and the mixture cooled and diluted with H2O gave 30% IV (R = R1 = H), m. >350° (HCONMe2-EtOH). By this treatment, I (R = H) with Ph in place of CN, was deoxygenated quant. to II (R = R1 = H, R2 = Ph) (unpublished work). Ir spectra of IV (R = R1 = H) and an authentic sample prepared by the method of Curd, et al. (CA 44, 3501e) were identical. The following sequence is suggested for this reaction: I(R = H ) → III → III(with CO2H in place of CONH2) which by decarboxylation gave 3-hydroxyquinoxaline 1-oxide, which by rearrangement gave 2,3-dihydroxyquinoxaline (loc. cit.), then bromination by Br formed by the action of part of the N-oxide on HBr or by aerial oxidation of HBr. In contrast, I (R = H) was unchanged by refluxing 8 hrs. with a 1:1 mixture of concentrated HCl and HOAc, or by heating under reflux with AcCl in a sealed tube at 100° 72 hrs. III, heated with a 1:1 mixture of HCl and HOAc, gave 2,3-dihydroxyquinoxaline. A mixture of this with fuming HBr refluxed 8 hrs. gave 20% monobromo derivative, m. >350° (HCONMe2-EtOH), which was identical in ir spectrum with IV (R = R1 = H) prepared from I (R = H) or III. Also the addition of a calculated amount aqueous KBrO3 to a solution of 2,3-dihydroxyquinoxaline in hot, fuming HBr precipitated at once a quant. yield of monobromo derivative, m. >350° (HCONMe2-EtOH), identical in ir spectrum with IV (R = R1 = H) prepared from I (R = H) or III. Either of these monobromo derivatives refluxed 3 hrs. with anhydrous K2CO3 and Me2SO4 in Me2CO, the mixture filtered, and the filtrate concentrated gave a good yield of IV (R = R1 = Me), m 205-6° (EtOH), the ir spectrum and mixed m.p. of which were identical with a sample prepared by the methylation of IV (R = Me, R1 = H) with Me22SO4 and aqueous NaOH. Curd, et al. (loc. cit.) recorded its m.p. as 205-6°. Hydrogenation of 4-bromo-2-methylamino-1-nitrobenzene in EtOH over Pd-C gave 4-bromo-2-methylaminoaniline, which, refluxed in EtOH solution with Et oxalate 3.5 hrs. gave IV (R = Me, R1 = H), m. 325-7° (HOAc). In the experiment, the researchers used many compounds, for example, 6-Bromoquinoxaline-2,3(1H,4H)-dione (cas: 1910-90-3SDS of cas: 1910-90-3).
6-Bromoquinoxaline-2,3(1H,4H)-dione (cas: 1910-90-3) belongs to quinoxaline derivatives. Condensed heterocycles of quinoxalines have become attractive targets in synthetic and medicinal chemistry due to their significant biological activities. The antitumoral properties of quinoxaline compounds have been of interest. Recently, quinoxaline and its analogs have been investigated as the catalyst’s ligands.SDS of cas: 1910-90-3
Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider