o-Dianisidine

o-Dianisidine is an organic compound with the formula [(CH₃O)(H₂N)C₆H₃]₂. A colorless or white solid, it is a bifunctional compound derived via the benzidine rearrangement from o-anisidine.

o-Dianisidine is a precursor to some azo dyes by formation of the bis(diazonium) derivative, which is coupled to diverse aromatic compounds. Some commercial dyes derived from o-dianisidine include C. I. Direct Blue 1, 15, 22, 84, and 98.^[1]

o-Dianisidine is also used in assaying activity of peroxidase in lab. The general reaction of a peroxidase is as follows.

${\displaystyle {\ce {ROOR'+{\overset {electron \atop donor}{2e^{-}}}+2H+->[{\ce {Peroxidase}}]{ROH}+R'OH}}}${\displaystyle {\mathrm {ROOR} {\vphantom {A}}^{\prime }{}+{}{\overset {\mathrm {electron} \atop \mathrm {donor} }{2,円\mathrm {e} {\vphantom {A}}^{-}}}{}+{}2,円\mathrm {H} {\vphantom {A}}^{+}{}\mathrel {\xrightarrow {\mathrm {Peroxidase} } } {}{\text{ROH}}{}+{}\mathrm {R} {\vphantom {A}}^{\prime }\mathrm {OH} }}

Where the ROOR' can be hydrogen peroxide, and the electron donor be o-dianisidine.

The manufacture and degradation of o-dianisidine, like other benzidene derivatives, has attracted regulatory attention.^[2] It is also used as a reagent in biochemistry in testing for peroxides.