6-NITROQUINOXALINE

a. [0169] To a solution of 4-nitrobenzene-l, 2-diamine (2.0 g, 13.07 mmol, 1.0 eq) in water (80 mL), was added dropwise glyoxal (4.0 mL, 31.37 mmol, 40% in H20, 2.4 eq). The mixture was heated to 100 C for 2 h under N2. After cooling, the mixture was filtrated and the solid was washed with water, dissolved in DCM, dried over Na2S04 and concentrated under vacuo to give the product (2.2 g, yield: 96.17%); LC/MS: m/z (M++l) = 176.Glyoxal (2.8 ml, 24 mmol, 40%) is added slowly to a solution of 4-nitro-phenylene-1, 2-diamine (1.53 g, 10 mmol) in water (30 ml). The mixture is heated at reflux for 4 h. After cooling, the reaction mixture is filtered under vacuum, washed with water and dissolved in dichloromethane. The solution is dried on anhydrous MgSO4 and concentrated under vacuum.Yield: 93%1H NMR (400 MHz, CDCl3) delta ppm: 8.26 (d, J=9.2 Hz, 1H); 8.52 (dd, J=9.2 Hz, J=2.4 Hz, 1H); 9.01 (s, 3H).-C NMR (50 MHz, CDCl3) delta ppm: 123.4, 125.9, 131.3, 141.9, 145.3, 147.0, 147.6, 147.9.ESI-MS m/z: 176 ([M+H]+, 23).IR cm-1: 740, 810, 850, 870, 930, 955, 1020, 1075, 1130, 1190, 1205, 1295, 1345, 1370, 14209, 1445, 1490, 1520, 1545, 1585, 1610, 3055, 3090.A solution of nitroaniline 272 (1.04g, 6.76 mmol) in 2-propanol (35 mL) was treated with 40% aqueous glyoxal (0.85 mL, 7. 4mmol, 1.1 eq. ) (or any other 1, 2-dicarbonyl compound, 1.1 eq). The mixture was stirred at 80 OC for 2h and concentrated in vacuo to afford the title compound 273, which was used for the next step without further purification. LRMS: (calc.) 175.1 ; (obt. ) 176.1 (MH) +.

Molecular Weight:175.14
XLogP3:1.3
Hydrogen Bond Acceptor Count:4
Exact Mass:175.038176411
Monoisotopic Mass:175.038176411
Topological Polar Surface Area:71.6
Heavy Atom Count:13
Complexity:204
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes