The Reaction of Phthalic Anhydride with Diethylenetriamine and Triethylenetetramine. A Literature Correction

Article abstract of DOI:10.1246/bcsj.71.717

A report that phthalic anhydride reacts with diethylenetriamine in acetic acid to form hydrogen phthalate salt of bis-(2-phthalimidoethyl)amine predominantly was reinvestigated. The major product that we obtained was bis(2-phthalimidoethyl)amine, some amide, and very little of the salt. With linear triethylenetetramine, we did not obtain N,N'-bis(2-phthalimidoethyl)ethylenediamine, nor the rearranged tris(2-phthalimidoethyl)amine or 1,4-bis(2-phthalimidoethyl)piperazine reported. A novel amide - 2-{N-2-phthalimidoethyl-N-[2-(2-phthalimidoethyl)aminoethyl]carbamoyl}benzoic acid - was formed as the major product instead. The products reported in the literature are attributed to branched and cyclic amines in their triethylenetetramine, and not to rearrangement reactions. Such possibility is supported by analysis of triethylenetetramine from the same supplier (ca. 65% linear), and our failure to duplicate the results with an authentic triethylenetetramine. Several reported compounds were prepared from pure amines, with no evidence of isomerization.