Quinoxaline N-Oxideに関する研究(第8報) : 2-AlkylquinoxalineのN-Oxidationについて

抄録

As a supplement to the preceding report, N-oxidation of 2-alkylquinoxalines [ethyl (II), isopropyl (III), tert-butyl (IV)] with monoperphthalic acid was attempted. From its result, considerations were made on the effect of the alkyl group on the adjacent ringnitrogen. With the ethyl group, its electronic effect (its electron-donating nature is considered to increase the basicity of the adjacent ring-nitrogen and accelerate N-oxidation) is offset by its steric effect (considered to interfere with N-oxidation by the steric interference), and the substituent does not affect the reaction to a great extent. In the isopropyl and tert-butyl groups, their steric effect becomes greater, and the formation of N-oxide become difficult in the case of ring-nitrogen adjacent to the tert-butyl group.