The chemistry of ortho-benzoquinones. Part IV. Addition of primary aromatic amines to 1,2-benzoquinone

Abstract

The addition of aniline and some substituted anilines to 1,2-benzoquinone has been reinvestigated with purified quinone. Two principal products are formed the 4,5-diarylamino-1,2-benzoquinone and the 2,5-diarylamino-1,4-benzoquinone monoanil. The proportions of the two products depends on the reaction medium. The former product predominates in methanol with only a trace of the latter, but the situation is exactly reversed in ether where the disubstituted anil is formed almost exclusively. A similar solvent effect occurs when the quinone is reacted with o-phenylenediamine which yields mainly 2,3-dihydroxyphenazine in methanol but predominately phenazine in ether.