109541-20-0Relevant academic research and scientific papers
REGIOSELECTIVITY IN THE REACTION OF NITROQUINOXALINE-N-OXIDES WITH PHOSPHORYL CHLORIDE
Nasielski-Hinkens, R.,Vyver, E. Vande,Nasielski, J.
, p. 663 - 670 (2007/10/02)
6-nitro-, 2-methyl-6-nitro- and 2,3-dimethyl-6-nitroquinoxaline have been transformed into their N-oxides by MCPBA in chloroform; the nitro group orients the oxygen atom preferentially to nitrogen atom N1, but the N4:N1 selectivity is diminished in the methylated derivatives.Under the action of POCl3 (the Meisenheimer reaction), the N-oxides of the unmethylated compounds are transformed into chloro-nitroquinoxalines having lost the N-oxide oxygen atom.The orientation of the entering chloride ion is discussed on the basis of electronic effects induced by the N-oxide and nitro groups, and it is suggested that the last step, the elimination of "HPO2Cl2" is a concerted process.
