526209-64-3Relevant academic research and scientific papers
An anomalous course of the condensation of 1,5-diaryl-3-formazyl glyoxylic acids with o-phenylenediamine. A simple synthesis of some benzimidazole-2-carboxamidarylhydrazones
Wiedermannova, Iveta,Slouka, Jan,Lemr, Karel
, p. 479 - 484 (2007/10/03)
The condensation of 1,5-diaryl-3-formazylglyoxylic acids 1 with o-phenylenediamine did not afford 1,2-dihydro-3-(1,5-diaryl-3-formazyl)-chinoxalin-2-ones 2 as it had been described in a previous communication1, but actually 1,5-diaryl-3-(2-benzimidazol-2-yl)-formazanes 7 with simultaneous elimination of formic acid. Also tetrazolium chlorides 3 and analogous picrates 4 described in the same communication1 were not derivatives of 1,2-dihydro-quinoxaline-2-one, but in fact they were 2,3-diaryl-5-(benzimidazol-2-yl)-tetrazolium chlorides 8 and analogous picrates 9. Formazans 7 were transformed by reductive splitting into benzimidazol-2-carboxamid arylhydrazones 10.
