N,N-Dimethylphenylenediamine
N,N-Dimethylphenylenediamine is an organic compound with the formula
H2NC6H4N(CH3)2. It is one of the phenylenediamines, a class of compounds that have long attracted attention for their redox properties. This diamine is, for example, easily oxidized to a deep red radical cation,[H2NC6H4N(CH3)2]+ which is called Wurster's Red. The related Wurster's Blue cation has four N-methyl groups(CH3)2NC6H4N(CH3)+2
Synthesis
Dimethyl-4-phenylenediamine is prepared by the nitration of dimethylaniline followed by reduction of the resulting 4-nitrodimethylaniline. A variety of methods have been examined.
Applications
Dimethyl-4-phenylenediamine can be converted to methylene blue by reaction with dimethylaniline and sodium thiosulfate in several steps:
It reacts with carbon disulfide to give the corresponding mercaptobenzothiazole:
- (CH3)2NC6H4NH2 + CS2 + S → (CH3)2NC6H3NCSH)S + H2S
History
Casmir Wurster discovered tetramethylphenylenediamine and its easy oxidation. Subsequent work revealed the variety of redox properties of the phenylenediamines.