ORGANIC SYNTHESIS AND INDUSTRIAL
Russian Journal of Applied Chemistry, 2011, Vol. 84, No. 12, pp. 2076−2082.
Pleiades Publishing, Ltd., 2011.
Original Russian Text © L.K. Sal’keeva, A.K. Shibaeva, E.K. Taishibekova, M.T. Nurmaganbetova, E.V. Minaeva, A.K. Sal’keeva, 2011, published in Zhurnal
Prikladnoi Khimii, 2011, Vol. 84, No. 12, pp. 1992−1998.
Synthesis and Potentiometric Analysis of Organophosphorus
Metal Complexones and Complexonates Based
on 2-Aminothiazole Derivatives
L. K. Sal’keeva, A. K. Shibaeva, E. K. Taishibekova, M. T. Nurmaganbetova,
E. V. Minaeva, and A. K. Sal’keeva
Buketov State University, Karaganda, Kazakhstan
Received October 18, 2010
Abstract—Synthesis conditions of 4-phenyl-2-amidothiazolyl acetate and 2-thiourido-4-diethylphosphothiazole
were developed, and the complexation capacity of these compounds in formation of mixed-ligand complexes was
studied. The optimal conditions and thermodynamic parameters of the complexation process were determined. The
potentiometric method was used to ﬁ nd thermodynamic parameters of the reactions of mixed-ligand complexation
with copper(II) and lead(II) ions, the composition of the complexes being formed on the basis of 4-phenyl-2-
aminothiazole and its phosphorylated derivatives was determined.
The synthesis of phosphorylated derivatives of thia-
zoles is of particular theoretical and practical interest.
The complexation capacity of 2-[diethylamido-(4'-phe-
with cations of various metals has been demonstrated
The fundamental aspects of the complexation of
phosphorylated ligands have been revealed for the ex-
ample of compounds whose structure fragmentarily in-
groups: fully phosphorylated
derivatives of amines, i.e., complexones combining two
types of complexing groups (i) phosphone and (ii) car-
boxy, oxyethyl, and mercaptoethyl [2–4].
The presence of multibasic salt-forming groups
and a highly basic nitrogen atom in the structure of the
phosphorylated complexone provides their successive
dissociation in a wide range of pH values for most of
cations. It is known that, when interacting with transi-
tion metals, phosphorus-containing complexones form
strong hydrogen or hydrogen-bonded complexes, which
is uncharacteristic of carboxy-containing prototypes.
The potential ability of aminoalkylphosphonic ac-
ids to exhibit an enhanced denticity due to the oxygen
of phosphone groups favors complexation with rare-
earth elements for which a large coordination number
and high oxygen afﬁ nity is known to be characteristic.
Alkylenepolyaminopolyalkylphosphonic acids form
highly stable mononuclear hydrogen or hydrogen-bond-
Of interest as a complexing agent is a derivative of
2-amino-4-phenylthiazole (1), 4-phenyl-2-amiothiazo-
lylacetate (2), produced by the reaction of compound (1)
with acetyl chloride in the presence of triethylamine. The
structure of thiazolyl acetate includes an acetyl group
capable of enolization, with the +M effect of the amino
group making higher the electron density on the oxy-
gen of the carbonyl group, which apparently shifts the
equilibrium toward the enolic form. Thus, in our study
of 4-phenyl-2-aminothiazolyl acetate (2) as a complex-
ing agent, the ability of the object under study to form
intramolecular hydrogen bonds in both the ketonic and
enolic forms was taken into account (Scheme 1).
The choice of objects for study, containing a phos-
phorus atom or having the form of various functional
derivatives of 2-amino-4-phenylthiazole (1) without
a phosphorus atom, is governed by the fact that a combi-