2-Methyl-6-nitro-2 -quinoxalinone

Methyl-1,2-benzenediamine (215, R = Me) with the hydrate of 3,3,3-trifluoro-pyruvic acid gave a mixture of isomers (216, R = Me) and (217, R = Me) (dioxane, reflux, 30 min 98%) from which neither appears to have been isolated in a pure state in contrast, 4-nitro-1,2-benzenediamine (215, R = NO2) and the same synthon gave a mixture of 6-nitro- (216, R = NO2) and 7-nitro-3-trifluoromethyl-2(l//)-quinoxalinone (217, R = NO2) (dioxane, reflux, 4 h 95%), from which both isomers were isolable, albeit with... 

Dimethoxy-1 -methyl-3-p-nitrostyryl-2( l//)-quinoxalinone gave 3-p-amino-phenethyl-6,7-dimethoxy-l-methyl-2(l//)-quinoxalinone (102) (H2, Pt02, AcOEt, 20°C 72% note incidental reduction of the nitro group). 

Methyl-6-nitro-2(l//)-quinoxalinone gave the 2-chloro-3-methyl-6-nitroqui-noxaline (12) (POCI3, PhNMe2, reflux, 2h 86%). ... 

Ethyl-l-methyl-2(17T)-quinoxalinone 4-oxide Ethyl 3-morpholino-2-quinoxalinecarboxylate Ethyl 6-nitro-2-quinoxalinecarboxylate... 

Ethoxy carbonylmethyl-l-methyl-2(lff)-quinoxalinone 4-oxide 3-Ethoxy carbonylmethyl-6/7-nitro-2(lff)-quinoxalinone... 

Methyl-3-morpholinoquinoxaline 6-Methyl-3-morpholino-2(177)-quinoxalinone 6-Methyl-2/3-(2-morpholinovinyl)quinoxaline 6-Methyl-7-nitr o-2,3-dioxo, 1,2,3,4-tetrahydro-5-quinoxalinecarboxylic acid 2-Methyl-6-nitro-3-phenylquinoxaline... 

Nitration of 6,7-disubstituted 3,4-dihydro-2(l//)-quinoxalinones with fuming nitric acid in trifluoroacetic acid produces the 5-nitro-2,3(1/7, 4//)-quinoxalinediones in good yields <1995JOC5838>. Methyl 6-methyl-2,3(l//,4//)-quinoxalinedione-5-carboxylate is regioselectively nitrated with a mixture of potassium nitrate in concentrated sulfuric acid to give the corresponding 7-nitro derivative <1999JHC1271>. 

The infrared spectra of quinoxaline mono- and di-./V-oxides 3-quin-oxalinone 1-oxides, and 1-hydroxyquinoxaline 2,3-diones have been reported, and the ring stretching vibrations and C=0 and N—O stretching frequencies were assigned.267 2-Methyl-6-amino- and 2-methyl-6-nitro-l,2,3,4-tetrahydro-3-quinoxalinones have been examined... 

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