Patent Number: 6,169,204

Title: Phosphoric acid salts of an aromatic diamine

Abstract: The present invention relates to a phosphoric acid salt of N-methyl-o-phenylenediamine and processes for making the same. In preferred embodiments of the invention, the phosphoric acid salt of N-methyl-o-phenylenediamine has the general Formula I ##STR1## wherein n is a number between 0.5 and 1.0, between 0.7 and 0.8, or between 0.75 and 0.78. The process for making the phosphoric acid salt of N-methyl-o-phenylenediamine comprises (a) dissolving the N-methyl-o-phenylenediamine in a first solvent, and (b) reacting the dissolved N-methyl-o-phenylenediamine with crystalline phosphoric acid or phosphoric acid dissolved in a second solvent.

Inventors: Schneider; Heinrich (late of Ingelheim, DE)

Assignee: Boehringer Ingelheim Pharma KG

International Classification: C07C 211/51 (20060101); C07C 211/00 (20060101); C07C 211/00 ()

Expiration Date: 01/02/2018