1- Phenacylquinoxalinium bromide

Quinoxaline and phenacyl bromide gave 1-phenacylquinoxalinium bromide (211) (neat reactants, 60°C, -5 min 30%). ... 

The reaction of 1-phenacylquinoxalinium bromide 39 with nitromethane in its boiling solution in the presence of Na2C03 for 6 h leads to 3-nitro-2-phenylpyrrolo [l,2-a]quinoxaline 40 (Scheme 3.14) (Kiel and Krohnke 1972). 

Scheme 3.24 Synthesis of l-benzoylp5nrolo[l,2-a]quinoxalines from 1-phenacylquinoxalinium bromide enes with the use of Mn02 as oxidizing agent...

Quinolinium ylids react similarly to give 3-nitropyrrolo[l,2-a]quinolines (11) (40-45%) and A-phenacylquinoxalinium bromide gives 3-nitro-2-phenylpyrrolo[l,2-a]quinoxaline 12 (41%).J Neither N-acetonyl- nor N-phenacylpyridinium bromide undergoes cyclization with nitromethane. However, when the pyridine ring carries a nitrile group at the 3-position, a 1-nitroindolizine (13) is formed.1... 

Phenacylquinoxalinium bromide (67) reacts with nitromethane in the presence of sodium carbonate to give the 3-nitro compound 68 in 41% yield. The quaternary salt 67 has also been reacted with dimethyl acetylenedicarboxylate to give the 1 1 adduct 69. ... 

Two other syntheses of a less general nature have also been reported. Reaction of phenacylquinoxalinium bromide (15) with phenyl isocyanate in the presence of triethylamine gave the tetrahydro compound 16. Condensation of 2-aminoquinoxaline with the perfluoro compound 17 gave the bisimino derivative 18. °... 

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