Unexpected reduction of ethyl 3-phenylquinoxaline-2- carboxylate 1,4-di-N-oxide derivatives by amines.
The unexpected tendency of amines and functionalized hydrazines to reduce ethyl 3-phenylquinoxaline-2-carboxylate 1,4-di-N-oxide (1) to afford a quinoxaline 1c and mono-oxide quinoxalines 1a and 1b is described. The experimental conditions were standardized to the use of two equivalents of amine in ethanol under reflux for two hours,with the aim of studying the distinct reductive profiles of the amines and the chemoselectivity of the process. With the exception of hydrazine hydrate, which reduced compound 1 to a 3-phenyl-2-quinoxalinecarbohydrazide derivative, the amines only acted as reducing agents.
Lima
Lidia M
LM
Unidad en Investigación y Desarrollo de Medicamentos, Centro de Investigación en Farmacobiología Aplicada (CIFA), University of Navarra, 31080 Pamplona, Spain.
Vicente
Esther
E
Solano
Beatriz
B
Pérez-Silanes
Silvia
S
Aldana
Ignacio
I
Monge
Antonio
A
D000588:Amines / Q000737:chemistry*; D003497:Cyclic N-Oxides / Q000737:chemistry / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction; D010087:Oxides / Q000378:metabolism*; D011810:Quinoxalines / Q000737:chemistry / Q000378:metabolism*
D000588:Amines; D003497:Cyclic N-Oxides; D010087:Oxides; D011810:Quinoxalines; C526932:ethyl 3-phenylquinoxaline-2- carboxylate 1,4-di-N-oxide