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.^[2] The related Wurster's Blue cation has four N-methyl groups (CH₃)₂NC₆H₄N(CH₃)+2

Structure of Wurster's Red bromide with bond distances in picometers

N,N-Dimethylphenylenediamine

Names
Preferred IUPAC name N1,N1-Dimethylbenzene-1,4-diamine
Other names p-Aminodimethylaniline; N,N-Dimethyl-p-phenylenediamine; 4-(Dimethylamino)aniline; p-Amino-N,N-dimethylaniline; p-(Dimethylamino)aniline; DMPPDA; Dimethyl-p-phenylenediamine; 4-Amino-N,N-dimethylaniline; p-Dimethylaminophenylamine; DMPD
Identifiers
CAS Number	99-98-9 Y
3D model (JSmol)	Interactive image
ChemSpider	13884246 Y
ECHA InfoCard	100.002.552
PubChem CID	7472
UNII	7GZH2FMK7X N
CompTox Dashboard (EPA)	DTXSID6025149
SMILES CN(C)C1=CC=C(C=C1)N
Properties
Chemical formula	C8H12N2
Molar mass	136.198 g·mol−1
Appearance	colorless solid
Density	1.036 g/cm³
Melting point	53 °C (127 °F; 326 K)[1]
Boiling point	262 °C (504 °F; 535 K)[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

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.^[3]

Applications

Dimethyl-4-phenylenediamine can be converted to methylene blue by reaction with dimethylaniline and sodium thiosulfate in several steps:^[4]

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.^[5] Subsequent work revealed the variety of redox properties of the phenylenediamines.^[6]