59483-60-2Relevant academic research and scientific papers
Oxidative Cyclizations. VII. Cyclization of 2-Substituted Anilines with Alkaline Hypohalite
Dyall, Leonard K.
, p. 2013 - 2026 (2007/10/02)
The Green-Rowe oxidation of 2-nitroanilines with alkaline hypohlorite, to yield benzofuroxans, is demonstrated by studies of the visible spectra of transient intermediates to proceed through N-chlorination and a singlet nitrene.Two variations on the route to the nitrene are possible.The cyclization step is represented as an internal capture of the nitrene by the ortho substituent, and on this basis the Green-Rowe oxidative cyclization is now extended to anilines whose ortho substituent is benzoyl or phenylazo.It is not however successful for ortho phenyl.Azo compounds were observed as byproducts in some of these reactions, and are shown to arise via N,N-dichloroanilines.
Oxidative Cyclizations. VI Mechanism of Cyclization of N-Chloro-2-nitroanilines to Benzofuroxans under Alkaline Conditions
Chapman, Kenneth J.,Dyall, Leonard K.,Frith, Lynn K.
, p. 341 - 354 (2007/10/02)
An improved synthesis of N-chloro-2-nitroanilines used chlorine in CCl4 solution to halogenate the 2-nitroaniline.Treatment of these CCl4 solutions of the N-chloroamines with methanolic lithium methoxide, or potassium t-butoxide in t-butylalcohol, produced a transient red colour, and quantitative yields of the corresponding benzofuroxan (benzofurazan 1-oxide) were obtained.U.v and e.s.r. spectra indicated that the red species is the conjugate base of the N-chloroamine.On the basis of rate measurements, it is concluded that this red anion ejects chloride ion irreversibly to yield a singlet ortho-nitrophenylnitrene, which then rapidly cyclizes to the benzofuroxan.The ortho-nitro group does not assist in chloride ion ejection.
