Patent ID: 7307190

Claim:
A process for the preparation of m-toluenediamine comprising: a) hydrogenating dinitrotoluene in the presence of a catalyst, b) separating the catalyst, water and optionally solvent from the product of a) to obtain crude toluenediamine, and c) distilling the crude toluenediamine in a distillation column having a separating wall to separate the crude toluenediamine into at least four product streams P 1 , P 2 , P 3 and P 4 wherein (i) the product stream P 1 comprises low boilers, (ii) the product stream P 2 comprises o-toluenediamine, (iii) the product stream P 3 comprises m-toluenediamine, and (iv) the product stream P 4 comprises high boilers and m-toluenediamine.