Aryliminodimagnesium Reagents. V. The Reaction with Bifunctional Nitroarenes

Article abstract of DOI:10.1246/bcsj.56.788

The reactions of p-methylphenyliminodimagnesium reagent (p-MeC6H4N(MgBr)2) with p- and m-dinitrobenzenes, bis(p-nitrophenyl)methane, bis(p-nitrophenyl) sulfide and ether, p- and m-nitrobenzaldehydes as well as 4-nitro-4'-methylbenzophenone were investigated. p-Dinitrobenzene, which is the strongest electron-acceptor among the substrates used, gave ca. 30percent combined yield of bis(azoxy) and azoxy azo products.The oxidative coupling product, 4,4'-dimethylazobenzene, was isolated in 20-30percent yields.About 60percent combined yield of the bis(azoxy) and azoxy azo products was obtained in the same reaction with m-dinitrobenzene, which is less electron-accepting than the p-isomer.In the reaction of bis(p-nitrophenyl)methane, bis(p-nitrophenyl)sulfide and ether with five molar amounts of the reagent, ca. 70percent combined yields of bis(azoxy), azoxy azo, and bis(azo) products were obtained.On the treatment of the nitrobenzaldehydes and the nitrobenzophenone, in contrast, the reaction took place exclusively on the nitro group.The results are discussed in terms of the electron-accepting ability of substrates.