o-Toluidine is produced industrially by nitration of toluene to give mixture of nitrotoluenes, favoring the ortho isomer. This mixture is separated by distillation
ortho-Toluidine is used as an intermediate in the synthesis of the large-volume herbicides, metolachlor and acetochlor, in the manufacture of more than 90 dyes and pigments (e.g. acid-fast dyestuffs, azo pigment dyes, triarylmethane dyes, sulfur dyes, and indigo compounds), and as an intermediate for synthetic rubber