[3,5-Dinitrobenzoic acid anhydride as reagent for the characterization of drugs and for the activation of polarographically inactive compounds].

Drugs with primary or secondary amino groups react with 3,5-dinitrobenzoic acid anhydride under catalysis of pyridine derivatives almost quantitatively to yield the corresponding amides which are reducible at the dropping mercury electrode (DME). 3,5-Dinitrobenzoic acid will be separated by thin layer chromatography. The limit of detection by DPP is in the range of 10(-8) M. The electrode reaction is irreversible.