Preparation of 5-(p-Chlorophenylazo) Resacetophenone by Two Routes and Using its Oxime as Reagent for Qualitative and Quantitative Analysis of Some Bivalent Metals

Abstract

Resacetophenone was synthesised from resorcinol by Nencki's reaction
and then coupled with diazonium salt of p-chloroaniline-to'obtain 5-(p-chlorophenylazo)
resacetophenone. An alternate route was tried by changing
the sequence of the reaction. Resorcinol was first coupled with
diazonium salt of p-chloroaniline and then subjected to Nencki's reaction.
The results of experiments, elemental analysis and IR spectral data suggested
that the compounds obtained by both the methods were same. These
also indicated that coupling before or after Nencki's reaction did not involve
any structural change. Position of coupling was ascertained by the
preparation of reductive derivative of the azo compound followed by conversion
of   —NH₂ group to  —OH group.
Further, the compound was converted to its oxime with hydroxylamine
hydrochloride. The oxime was coloured and had high molecular weight.
It was consequently used as a chelating agent for qualitative and quantitative
analysis of bivalent metals like Cu, Zn and Ni. On the basis of the
quantitative data the structures of the complexes were assigned and probable
use of the oxime as analytical reagent was suggested.