3-Methoxycarbonylmethyl-2 quinoxalinone

Methoxycarbonylmethyl-1 -methyl-2( 177)-quinoxalinone gave 3-[a-methoxy-carbonyl-a-(p-tolylhydrazono)methyl]-l-methyl-2(177)-quinoxalinone (171) [ i-MeCcH4N20Ac (prepared in situ), ACOH-H2O, 20°C 95°C, 1 h 36%] " analogous esters likewise." " ... 

Methoxycarbonylmethyl-l-methyl-2(177)-quinoxalinone (223, X = O) gave 3-methoxycarbonylmethyl-l-methyl-2(177)-quinoxalinethione (223, X = S) (P2S5, PbCl, 125°C... 

The extranuclear C-nitrosoquinoxalines are typified by 3-(a-methoxycarbonyl-a-nitrosomethyl)-2(l/i)-quinoxalmone (66), made by nitrosation of 3-(methoxy-carbonylmethyl)-2(l/f)-quinoxalmone (65) [AcOH, CI3CO2H, C5H11ONO, 20°C, 3 h 91% spectra suggest that the hydroxyimino tautomer (67) may predominate] and was subsequently reduced to afford 3-(a-amino-a-methoxycarbonylmethyl)-2(l//)-quinoxafinone (68) (PtOa, H2, 1 atm, THF, EtOH, 20°C, 4 h 59%) also by 3-[a-(4-amino-5-methyl-4//-l,2,4-triazol-3-yl)-a-nitrosomethyl]-2(l//)-quinoxa-linone (69, R = NO), prepared by nitrosation of 3-(4-amino-5-methyl-4//-1,2,4-triazol-3-ylmethyl)-2(177)-quinoxalinone (69, R = H) [NaN02 ( 1.25 equiv), AcOH, H2O, no further details 79%]." ... 

Methoxycarbonylmethyl-2(l//)-quinoxalinone (220) with p-chlorobenzene-diazonium chloride gave a product, initially formulated as 3-[a-(p-chloro-phenylazo)-a-methoxycarbonylmethylene]-3,4-dihydro-2(l//)-quinoxalinone (221) but later as the tautomeric 3-[a-(p-chlorophenyUiydrazono)-a-methoxy-carbonylmethyl]-2(l//)-quinoxalinone (222) (HCl, H2O, AcOH, <5°C, 10 min, then 95°C, 30 min 90%). ° Such tautomerisms have been studied in some detail.(See also Section 6.6.)... 

---