A simple procedure for obtaining 1-phenyl-3-methyl-4-trifluoroacetyl-pyrazolone-5 (HPMTFP), a promising metal extractant, is described. Recrystallization studies reveal that only one tautomer can be isolated, sometimes with one molecule of water of crystallization, contrary to reports that a yellow enol and a white keto tautomer can be obtained from n-hexane and aqueous ethanol respectively. The melting points and colours of some of the metal chelates of HPMTFP are tabulated and in the case of Hg(II) and Cu(II) chelates, differ from those reported by others. Solubility data for some of the metal chelates of HPMTFP are also given.
Talanta 05/1982; 29(4):275-8. DOI:10.1016/0039-9140(82)80112-4