Dimethyl-4-phenylenediamine is an amine.

It has been used as an accelerator for the vulcanization of rubber.

[2] It can be used in oxidase tests.

Dimethyl-4-phenylenediamine is made by the nitrosylation of dimethylaniline followed by reduction.

Dimethyl-4-phenylenediamine can be converted to methylene blue by reaction with dimethylaniline and sodium thiosulfate in several steps:[3] It is used as accelerator for the vulcanization of rubber, being first converted to the corresponding mercaptobenzothiazole.