In previous papers from this laboratory, 2 the preparation and properties of fi- diaminoterephthalic acid and several of its derivatives have been described. The results secured seemed to us of sufficient interest to justify the extension of the investigation to the analogous 4, 6-diaminom-phthalic acid. The similarity in the structure of these two acids is seen at once from a glance at their constitutional formulas: HOOC,,,/NH,
