Patent ID: 8188316
Filing Date: 2012-05-29
Classification: C07C,Y02P

Abstract:
1. A process for preparing a complex of 2,3,5,6-tetraaminotoluene and an aromatic diacid, wherein the complex is generally described by Formula I wherein Ar is a divalent group containing one or two aromatic rings, wherein said one or two aromatic rings may contain one or more substituents in addition to the —COOH groups shown, wherein said one or more substituents are selected from the group consisting of OH, SH, methyl, ethyl, F, Cl, and Br; comprising the sequential steps under exclusion of oxygen: a) providing a solution of 2,3,5,6-tetraaminotoluene (Formula II) in alcohol; b) contacting the solution with a solution of an aromatic dicarboxylic acid generally described by Formula III in a solvent, wherein the solvent is selected from N,N-dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and mixtures thereof; wherein the aromatic dicarboxylic acid is insoluble in water; and wherein the molar ratio of aromatic dicarboxylic acid to the 2,3,5,6-tetraaminotoluene salt is from 1:1 to 1.1:1; thereby producing and precipitating the complex generally described by Formula I; and c) cooling, filtering, and washing the precipitated complex.