N-Alkyl-N'-[(alkyl/aryl)(alkoxy/aroxy)phosphoryl]ureas: Synthesis and extraction properties toward f-elements

Article abstract of DOI:10.1007/s11172-014-0408-y

A reaction of chlorophosphonates R¹R²P(O)Cl with NaOCN and subsequent treatment with octylamine lead to phosphorylureas R ¹R²P(O)NHC(O)NHC⁸H¹⁷-n (R ¹ = EtO, PhO; R² = Me, Ph). Their extraction capability toward U^VI and a number of tervalent lanthanides (La^III, Nd^III, Ho^III, Yb^III) was studied. Efficiency and selectivity of these ligands in the extraction of f-elements from nitric acid solutions to chloroform were compared with extraction properties of a model phosphine oxide-type phosphorylurea MePhP(O)NHC(O)NHC₈H ₁₇-n and carbamoylphosphine oxide Ph₂P(O)CH ₂C(O)NBu₂.

Full text of DOI:10.1007/s11172-014-0408-y

Russian Chemical Bulletin, International Edition, Vol. 63, No. 1, pp. 141—148, January, 2014
141
NꢀAlkylꢀN´ꢀ[(alkyl/aryl)(alkoxy/aroxy)phosphoryl]ureas:
synthesis and extraction properties toward fꢀelements*
E. I. Goryunov,a T. V. Baulina, I. B. Goryunova, A. G. Matveeva, A. M. Safiulina, and E. E. Nifant´ev
a
a
a
b
a
aA. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences,
2
8 ul. Vavilova, 119991 Moscow, Russian Federation.
Fax: +7 (499) 135 5085. Eꢀmail: phoc@ineos.ac.ru
b"United Chemical Company Uralchem" Open Joint Stock Company,
1
0 Presnenskaya nab., 123317 Moscow, Russian Federation.
Fax: +7 (495) 721 8585. Eꢀmail: alfiya.safiulina@uralchem.com
1
2
A reaction of chlorophosphonates R R P(O)Cl with NaOCN and subsequent treatment
1
2
1
with octylamine lead to phosphorylureas R R P(O)NHC(O)NHC H ꢀn (R = EtO, PhO;
8
17
2
VI
R = Me, Ph). Their extraction capability toward U and a number of tervalent lanthanides
La , Nd , Ho , YbIII) was studied. Efficiency and selectivity of these ligands in the extracꢀ
III
III
III
(
tion of fꢀelements from nitric acid solutions to chloroform were compared with extraction
properties of a model phosphine oxideꢀtype phosphorylurea MePhP(O)NHC(O)NHC H ꢀn
8
17
and carbamoylphosphine oxide Ph P(O)CH C(O)NBu .
2
2
2
Key words: phosphorylureas, chlorophosphonates, oneꢀpot processes, extraction, lanꢀ
thanides, actinides.
Extraction as a method for recovery of valuable comꢀ
ponents and separation of elements with close properties
is widely used in atomic industry for reprocessing spent
nuclear fuel, in hydrometallurgy for obtaining hafniumꢀ
free zirconium, for separation of copper and iron, nickel
and cobalt, as well as for separation of rare earth elements.
The advantage of this method is its high productivity and
relatively simple automation. Therefore, a search for new
extractants possessing high extraction capability and selecꢀ
tivity is still a relevant problem. Among organophosphorus
extractants, the most frequently used are neutral organoꢀ
phosphorus compounds (OPC), which contain one or several
portance of extractants, besides efficiency, should also inꢀ
clude the cost of the starting materials and processability
of the synthesis of target compounds. Lately, a new family
of synthetically more available (as compared to carbꢀ
amoylmethylphosphine oxides (CMPO)) acetylꢀcontainꢀ
ing phosphine oxides5
—7
R R P(O)—X—C(O)Me was
1
2
studied. A number of diorganylphosphorylmonoureas
8
—12
and ꢀbisureas
were synthesized, which are the strucꢀ
tural analogs of CMPO containing an NH imide fragment
instead of the CH methylene bridge between the phosꢀ
2
phoryl and the carbonyl groups. A simple and technologiꢀ
cal oneꢀpot method was developed for the synthesis of this
1
3
donor centers capable of coordination with metal cations
type of compounds, and it appears that extraction propꢀ
erties of diorganylphosphorylmonoureas toward fꢀelements
are significantly better than those of the corresponding
carbamoyl analogs. In this case, Nꢀdiphenylphosphorylꢀ
N´ꢀnꢀalkylureas, especially N´ꢀnꢀoctyl derivatives, were
—3
(
monoꢀ, biꢀ, and polydentate ligands).1 The properties
of bidentate neutral OPC are well studied; they have two
coordination centers, one of which is the oxygen atom of the
P=O group, whereas the second center can be either simiꢀ
lar P=O oxygen atom (diphosphine dioxides, diphosꢀ
1
2
found to be the most efficient. Note that earlier Nꢀdiꢀ
1
2
1 2
phonates, and diphosphinates R R P(O)—X—P(O)R R ,
here and further X is alkylene bridges of different nature,
R is different alkyl, alkoxy, and aryl groups), or the oxygen
atom of the C=O group (for example, compounds with
alkoxyphosphorylureas were reported as possible extractꢀ
14
ants for actinides. At the same time, there are no literature
data on the extraction capability of phosphorylureas, whose
molecules simultaneously contain a P—C and a P—O—C
fragments (the phosphonate type). In continuation of our
studies on the search for efficient and selective extractants
for extraction and separation of lanthanides and actinides,
it seemed reasonable to synthesize a number of this type
phosphorylureas and study their extraction properties.
In the present work, we synthesized a series of earlier
unknown phosphonateꢀtype phosphorylureas 1—4, in the
1
2
3
a carbamoyl fragment R R P(O)—X—C(O)NR and
2
1
2
3
R R P(O)—X—C(O)NHR ). General correlations beꢀ
tween the extractant structure and its extraction capability
were established. However, evaluation of practical imꢀ
3
,4
*
Dedicated to Academician of the Russian Academy of Sciences
A. I. Konovalov on the occasion of his 80th birthday.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 0141—0148, January, 2014.
066ꢀ5285/14/6301ꢀ0141 © 2014 Springer Science+Business Media, Inc.
1

1
42
Russ.Chem.Bull., Int.Ed., Vol. 63, No. 1, January, 2014
Goryunov et al.
molecules of which simple alkyl, aryl, alkoxy, and aroxy
fragments are attached to the phosphorus atom in differꢀ
ent combinations, with the nꢀoctyl substituent being atꢀ
tached to the terminal nitrogen atom in all the cases. This
allowed us to highly correctly evaluate the influence of
substituents at the phosphorus atom on the extraction paꢀ
rameters of the ligands obtained.
formation of a white solid products, most likely, of the
polymeric nature. Since other representatives of phosphoꢀ
nic acid isocyanates can be similarly unstable, we decided
to develop practical oneꢀpot processes for the synthesis of
the corresponding phosphonateꢀtype Nꢀphosphorylureas.
A possibility to carry out such processes was demonꢀ
strated for the synthesis of urea 2 taken as an example
(
Scheme 2).* In the first step, phosphoryl chloride reacted
with NaOCN in the presence of MgCl in anhydrous aceꢀ
2
1
6
tonitrile at 20 C. In the second step, a calculated
amount of octylamine was added to the in situ obtained
phosphoryl isocyanate 7. After the reaction mixture was
workedꢀup, the target compound 2 was isolated in 88%
yield (calculated on the starting chlorophosphonate).
1
2
= EtO, R2 = Me (1); R = PhO, R2 = Me (2); R = EtO,
1
1
R
R
1
2
1
2
= Ph (3); R = PhO, R = Ph (4); R = Me, R = Ph (5)
Extraction of fꢀelements was chosen as an example to
study extraction capability of phosphorylureas 1—4,
whereas the phosphine oxideꢀtype phosphorylurea
PhMeP(O)NHC(O)NHC H ꢀn (5) and CMPO strucꢀ
Scheme 2
8
17
turally close to ureas Ph P(O)CH C(O)NBu (6) were
2
2
2
used as reference compounds.
Results and Discussion
The phosphonateꢀtype phosphorylureas were synꢀ
thesized according to the following scheme: phosphorꢀ
yl chloride  phosphoryl isocyanate  phosphorylurea,
which is thought1 to be the most rational approach to the
preparation of different types of Nꢀphosphorylated ureas.
It should be noted that a key step in this scheme, which
determines its overall effectiveness, is the synthesis of the
corresponding phosphoryl isocyanates.
5
R1 = EtO, R2 = Me (1, 8); R1 = PhO, R2 = Me (2, 7); R1 = EtO,
R
2
= Ph (3, 9); R1 = PhO, R2 = Ph (4, 10)
Compounds 1, 3, and 4 were obtained similarly.
31
1
Earlier,16 we have developed a simple, efficient, and
P{ H} NMR spectroscopy showed that the correꢀ
1
2
sponding phosphoryl isocyanates R R P(O)NCO 8—10
are mainly formed in the first step of these processes for all
the phosphoryl chlorides under study. After their treatꢀ
ment with nꢀoctylamine, the target phosphorylureas 1, 3,
and 4 were obtained in high yields (73—86%) (Table 1).
The ureas 1—4 are white crystalline compounds, staꢀ
ble in air and melting without decomposition. They are
virtually insoluble in water, hexane, and heptane and fairꢀ
ly well soluble in chloroform and DMSO. The structure of
these compounds was confirmed by elemental analysis, as
technological method for the preparation of monoisocyꢀ
anates of pentavalent phosphorus oxoacids consisting
in the reaction of phosphoryl chlorides with cheap comꢀ
mercially available NaOCN in anhydrous acetonitrile in
the presence of anhydrous magnesium chloride as a cataꢀ
lyst. In particular, this method was used to synthesize
methyl(phenoxy)phosphoryl isocyanate (7) in 73% yield,
which violently reacted with nꢀoctylamine in anhydrous
benzene at 20 C to give Nꢀ[methyl(phenoxy)phosꢀ
phoryl]ꢀN´ꢀoctylurea (2) in 87% yield (Scheme 1).
1
well as by IR spectroscopy and NMR spectroscopy ( H,
13
1
31
1
1
C{ H}, and P{ H}). The H NMR spectra of comꢀ
Scheme 1
pounds 1—4, whose molecules contain an asymmetric
phosphorus atom, exhibit magnetic nonequivalence of both
Me(PhO)P(O)NCO + nꢀC H17NH2
8
the geminal protons in the P—O—CH fragments and (in
2
most cases) the protons of the methylene groups in the
7
Me(PhO)P(O)NHC(O)NHC H17ꢀn
8
*
Chlorophosphonates used in this work were synthesized based
2
on the most efficient procedures described in the literature. An
original method was developed for the preparation of
Ph(EtO)P(O)Cl (see Experimental), which allowed us to obtain
this compound in the yield close to quantitative based on the
commercially available products PhP(O)(OEt) and PCl .
Phosphoryl isocyanate 7 appeared to be not stable
enough, and even on storage under inert atmosphere when
air moisture is absent, it gradually decomposes with the
2
5

Extraction with phosporylureas
Russ.Chem.Bull., Int.Ed., Vol. 63, No. 1, January, 2014
143
1
2
Table 1. Oneꢀpot synthesis of the phosphonateꢀtype Nꢀphosphorylureas R R P(O)NHC(O)NHC H ꢀn 1—4
8
17
R1
R2
Duration
of the first step
of the process/h
Phosphoryl
isocyanate
formed
Content of isocyanate
in the mixture (%)
Phosphorylꢀ
urea
obtained
Yield
(%)
31
1
( P{ H} NMR)
Me
Me
Ph
EtO
PhO
EtO
PhO
12
13
12
10
18
17
19
10
88
—
96
72
1
2
3
4
86
88
77
73
Ph
metal, sometimes even higher than basicity.19 However,
preliminary data obtained by conformational analysis (moꢀ
lecular mechanics) showed that steric availability of
both centers (P(O) and C(O)) capable of coordination
with metal cation is virtually the same in all the ureas
under study.
At the same time, variations of substituents at the phosꢀ
phorus atom, namely, the replacement of one C—P bond
with C—O—P, considerably changes lipophilicity of both
the ligand itself and its complexes, that, in turn, changes
solubilities and extraction properties of compounds. For
C(O)—NH—CH fragment, that naturally results in a sigꢀ
2
nificant complication of the spectral pattern in the region
characteristic of the signals for the protons of the correꢀ
sponding groups.
This oneꢀpot method for the synthesis of phosphoryꢀ
lureas 1—4 is distinguished by its simplicity and processꢀ
ability and, if necessary, can be easily reproduced on a large
scale. It is reasonable to suggest that this process can be
also used for the preparation of other representatives of the
phosphonateꢀtype Nꢀphosphorylureas.*
Extraction properties of phosphorylureas 1—4 toward
fꢀelements were studied for extraction of uranium(VI) and
the group of lanthanides(III) from aqueous nitric acid into
the organic phase, with the concentration of nitric acid
being varied and the concentrations of the salt in the aqueꢀ
example, the solubility of acids (PhO) P(O)OH and
2
–
1
Ph P(O)OH in water differ by almost 300 times (1.03•10
2
–
3
–1
20
and 3.6•10 mol L , respectively).
The results of the studies of liquid extraction of uranyl
and lanthanide ions for the same concentration of phosꢀ
ous phase and the ligand in CHCl being constant.
3
It is known that efficiency and selectivity of extraction
depends on many factors, and this dependence is comꢀ
plex. These factors include stability of extracted complexꢀ
es (structure of complexes, steric availability and basicity
of coordinating groups, ligand denticity, etc.), as well as
the hydrophilicꢀlypophilic balance of ligand and its comꢀ
plexes. Our analysis of the dependence of the metal distriꢀ
bution ratios (D) from the ligand structure included the
fact that the electron effect of substituents at the phosphoꢀ
rus atom17 usually correlates with both basicity of the phosꢀ
phoryl group and stability of the extracted complexes. The
phorylureas 1—5 in CHCl and the salt in aqueous phase
are given in Fig. 1.
From the data obtained for uranium (see Fig. 1, a), it
follows that the dependence of the distribution ratios DU
3
from the concentration of HNO is similar for ligands 1—5:
3
the DU values increase with concentration of HNO . The
3
efficiency of uranium extraction is low for all the ligands,
and the maximum values are reached at the highest conꢀ
centration of nitric acid. Also note a certain symbatic charꢀ
acter in the change of extraction capability with the change
of electron properties of substituents at the phosphorus
atom. Distribution ratios found at the maximum concenꢀ
P
constants  , characterizing electron effects of substituꢀ
ents at phosphorus atom, rather considerably vary for the
P
tration of HNO , as well as the  value characterizing
3
ligands 1, 2, 3, and 4: –1.17, –1.02, –0.69, and –0.54,
respectively. Such a change in the  values for this series
induction properties of substituents, decrease in the order
P
1, 2, 5 > 3 > 4.
As a first approximation, similarly to other OPC,5
,7,21
of related structures corresponds to the changes in the
1
8
VI
basicity of these compounds in nitromethane by 1 pK
it can be suggested that in the extraction of U , neutral
P
0
+
–
unit. The  value for the model ligand 5 is –1.44,
[UO (L) (NO ) ] and cationic [UO (L) (NO )] •NO
2 n 3 2 2 n 3 3
i.e., this ligand should be the most basic among comꢀ
pounds 1—5, other things being equal.
Steric effect of bulky substituents at phosphorus atom
has also important influence on the coordination with
(in the form of ion pairs) complexes (n  2) (for conveꢀ
nience, coordinated water molecules are not given) are the
main extracted species. In this case, an increase in the
concentration of nitric acid should lead to the increase in
the efficiency of extraction due to the shift of the equilibriꢀ
um to the side of the formation of the better extracted
neutral complexes.
The structure and composition of complexes formꢀ
ed during extraction of uranium with phosphorylꢀ
ureas under study are unknown. There are only first pubꢀ
*
In fact, in the case of Nꢀdiorganylphosphorylureas the correꢀ
sponding oneꢀpot procedure developed for the synthesis of
NꢀdiphenylphosphorylꢀN´ꢀnꢀalkylureas13 became afterwards
a general method for the design of a great variety of this class of
compounds.1
2

1
44
Russ.Chem.Bull., Int.Ed., Vol. 63, No. 1, January, 2014
a
Goryunov et al.
D
D
b
1
.0
0
0
0
0
0
.5
1
2
0.8
.4
.3
.2
.1
5
4
2
5
3
0
0
0
.6
.4
.2
3
1
4
1
2
3
CHNO3/mol L–1
1
2
3
CHNO3/mol L–1
D
c
D
d
1
1
0
0
.4
.0
.6
.2
1
1
0
.4
.0
.6
5
3
5
1
3
4
2
3
1
4
0.2
2
1
2
3
CHNO3/mol L–1
CHNO3/mol L–1
1
2
D
e
1
1
0
0
.4
.0
.6
.2
5
3
1
4
2
1
2
3
CHNO3/mol L–1
Fig. 1. Dependence of distribution ratios for UVI (a), LaIII (b), NdIII (c), HoIII (d), and YbIII (e) from the concentration of HNO in
3
the extraction with phosphorylureas 1—5 (0.01 M solution in CHCl ).
3
lications on the structure of 1 : 1 complexes of
rise with the raising in the concentration of HNO (see
3
Ph P(O)NHC(O)NHC H ꢀn with uranyl, thorium(IV),
Fig. 1, b, c). It can be suggested that for the extraction of
these lanthanides, the effect caused by the change in lipoꢀ
philicity of ureas 1—4 due to the presence of the C—O—P
bond considerably exceeds the influence on the extraction
of the differences in electron properties of substituents at
2
8
17
and europium(III) nitrates, in which a bidentate coordinaꢀ
tion of the ligand involving P=O and C=O groups and
a bidentate coordination of all the nitrato groups was sugꢀ
gested according to the data of IR spectroscopy.2 Noneꢀ
theless, it should be indicated that during extraction the
structure and composition of complexes can considerably
differ from those of crystalline and solid complexes synꢀ
thesized in the model experiments, that, for example, was
the case23 in the studies of the extraction mechanism
of CMPO.
2
1
2
the phosphorus atom, R and R . As a result, the efficienꢀ
III
III
cy of extraction of La and Nd with ligands 1—4 is
virtually the same within entire range of HNO concenꢀ
3
trations. In the case of ligand 5 (two C—P bonds), an
increase in the extraction capability with the increase in
the acidity of the medium is of pronounced character, and
VI
–1
In contrast to extraction of U , phosphorylureas 1—4
in the range of acid concentrations 1.4—3.75 mol L urea
III
III
III
III
virtually similarly extract La and Nd , with the disꢀ
tribution ratios being quite low, which insignificantly
5 extracts La and Nd considerably more efficiently
than the phosphonate derivatives 1—4.

Extraction with phosporylureas
Russ.Chem.Bull., Int.Ed., Vol. 63, No. 1, January, 2014
145
In the extraction of HoIII and YbIII, the distribution
ratios of all five phosphorylureas also rise with the raising
D
.2
1
in the concentration of HNO (see Fig. 1, d, e). The plots
3
of dependences for ligands 1—4 are almost linear, whereas
the plot for ligand 5 has somewhat more complicated patꢀ
1
.0
tern: the D value changes unevenly in the region of HNO
3
0.8
0.6
–
1
concentrations 0.074—2.20 mol L . Like in the extracꢀ
tion of La and NdIII, the distribution ratios for all the
ligands reach the maxima at the highest acidity of the
aqueous phase, with ligand 5 demonstrating the highest
III
0
.4
III
VI
efficiency. However, in contrast to extraction of La and
U
Yb
0
.2
III
III
III
Nd , ligand 3 extracts both heavy lanthanides Ho and
III
Ho
III
Yb better than related ligands 1, 2, and 4 within entire
III
Nd
1
range of HNO concentrations.
2
LaIII
3
3
Similarly to other organophosphorus ligands,5 it can
,21
4
6
Ligand
be suggested that the tervalent lanthanides are extracted
Fig. 2. Comparison of distribution ratios of LaIII, NdIII, HoIII
,
+
by phosphorylureas 1—5 as cationic [Ln(L) (NO ) ] •
III
VI
n
3 2
Yb , and U in the extraction with ligands 1—4 and 6 (0.01 M
solutions in CHCl ) from 3.75 M HNO , the initial concentraꢀ
–
0
•
(NO ) and neutral [Ln(L) (NO ) ] complexes (n  2, 3),
3 n 3 3
3
3
existing in the equilibrium. It is expected that with the
tion of lanthanide and uranyl nitrates in aqueous phase was
2.5•10–4 mol L
–1
.
increase in the concentration of HNO , the content of the
3
better extracted neutral complexes should increase.
Generally, the efficiency of extraction of lanthanides
with ligands 1—5 obeys a known24 rule on the change in
a group extractant for the separation of heavy and light
lanthanides from solutions of nitric acid into chloroform.
stability of lanthanide coordination complexes ("gadoliniꢀ
um angle"): (La > Nd) < (Ho < Yb), though for phosphorꢀ
ylureas 1, 2, 4, and 5, the selectivity toward pairs of heavy
and light lanthanides is low. A noticeable selectivity is
exhibited only by ligand 3. The distribution ratios in the
extraction with this compound for HoIII and Yb are
Experimental
1H, 13C{ H}, and P{ H} NMR spectra were recorded on
1
31
1
III
1
a Bruker AVꢀ400 spectrometer (400.13 MHz ( H), 100.61 MHz
( C{ H}), and 161.98 MHz ( P{ H}), solvent CDCl ). The sigꢀ
13
1
1
1
III
equal to 1.07 and 0.88, respectively, whereas for La and
3
III
nals for the residual protons of the deuterated solvent and the
signals for the carbon atoms of the deuterated solvent were used
Nd they are 0.46 and 0.48, that allows one to consider
ligand 3 as a group extractant for separation of heavy and
light lanthanides.
1
13
1
as references for the H and C{ H} NMR spectra, respectively;
5% aqueous H PO was used as an external standard for the
8
31
3
4
Extraction properties of phosphorylureas 1—4 were also
compared with the properties of one of the most known
bidentate extractant CMPO 6, which were studied under
the same experimental conditions (Fig. 2). The reference
ligand 6 extracts uranium slightly better, than all the ureas
studied. At the same time, the extraction coefficients of
1
P{ H} NMR spectra.
IR spectra were obtained on a MagnaꢀIR 750 (Nicolet) Fouꢀ
rierꢀtransform IR spectrometer in KBr pellets.
Elemental analysis was performed in the Laboratory of miꢀ
croanalysis of the A. N. Nesmeyanov Institute of Organoeleꢀ
ment Compounds of the Russian Academy of Sciences.
The salt NaOCN (Aldrich, 98%) was dried for 4 h at 120 C
in vacuo over P O ; nꢀoctylamine (Acros, 99+%) was distilled
III
III
La and Nd for all the ligands 1—4 and 6 lie within the
same range. Noticeable differences were observed only in
the extraction of heavy lanthanides. Phosphorylurea 3 exꢀ
2
5
over solid KOH before use; tetrachloromethane (pure grade),
benzene (reagent grade), and acetonitrile (Acros, 99+%) were
distilled over P O before use. Phosphorus pentachloride (anaꢀ
III
III
tracts Ho and Yb significantly more efficiently than
2
5
related compounds 1, 2, 4, and the reference ligand 6
see Fig. 2).
lytical grade) before the reaction was finely crushed and allowed
to stand for 2 h in vacuo (1 Torr) at 20 C. Diethyl phenylphosꢀ
phonate (Alfa Aesar, 97%) and anhydrous MgCl2 (Aldrich,
98%) were used as purchased.
(
In conclusion, we have developed a twoꢀstep scheme
for the synthesis of earlier unknown phosphonateꢀtype
Nꢀphosphorylureas based on the use of the most effiꢀ
cient and technological approaches of modern synthetic
chemistry: the catalytic reactions and oneꢀpot processꢀ
es. Extraction properties of the ligands synthesized toꢀ
ward a number of fꢀelements were studied. Phosphorylꢀ
1
6
Methyl(phenoxy)phosphoryl isocyanate (7), phenyl chloroꢀ
2
5
26
(
methyl)phosphonate, phenyl chloro(phenyl)phosphonate,
2
7
and ethyl chloro(methyl)phosphonate, as well as the model
1
1
compounds urea (5) and (N,Nꢀdibutylcarbamoylmethyl)ꢀ
2
8
diphenylphosphine oxide Ph P(O)CH C(O)NBu (6) were
2
2
2
synthesized and purified according to the known procedures.
urea (EtO)PhP(O)NHC(O)NHC H ꢀn (3), in contrast
8
17
Ethyl chloro(phenyl)phosphonate. Finely crushed PCl (26.3 g,
5
to other ligands of this type 1, 2, 4 and the reference
compounds (urea 5 and CMPO 6), can be considered as
0.126 mol) was added in portions over 2.5 h to a solution of
diethyl phenylphosphonate (27.0 g, 0.126 mol) in anhydrous

1
46
Russ.Chem.Bull., Int.Ed., Vol. 63, No. 1, January, 2014
Goryunov et al.
CCl (94 mL) under argon with stirring on a magnetic stirrer and
phosphonate (1.53 g, 0.008 mol) in anhydrous acetonitrile
(15 mL) with stirring on a magnetic stirrer under argon at 20 C.
The mixture was stirred until complete dissolution of MgCl2,
followed by addition of NaOCN (1.04 g, 0.016 mol) and stirring
for another 3 h at this temperature. The suspension obtained was
treated by octylamine (1.01 g, 7.84 mmol) and stirred for anothꢀ
er 1 h at 20 C. The solvent was evaporated in vacuo, the resiꢀ
due was treated with a mixture of DI water (30 mL) and acetoꢀ
nitrile (5 mL). The suspension obtained was stirred for 2 h,
a precipitate formed was filtered off, sequentially washed with
a mixture of DI water (17 mL) and acetonitrile (3 mL), a mixture
of 1% aq. hydrochloric acid (28 mL) and acetonitrile (2 mL),
and DI water (4×20 mL), then dried in air. The yield was 2.30 g
(88%), m.p. 85—86 C. Spectroscopic characteristics of the prodꢀ
uct obtained were identical to the characteristics of the comꢀ
pound synthesized by method A.
4
heating (50 C). After addition of PCl , the reaction mixture
5
was allowed to stand for 12 h at the same temperature. The
solvent and POCl formed were evaporated at 20 C in vacuo
3
using a waterꢀjet pump (60 Torr). The residue was fractionally
distilled in vacuo. The yield was 24.9 g (97%), b.p. 98—98.5 C
(
1 Torr) (cf. Ref. 29: b.p. 82 C at 0.01 Torr).
Nꢀ[Ethoxy(methyl)phosphoryl]ꢀN´ꢀnꢀoctylurea (1). Finely
powdered anhydrous MgCl (44 mg, 0.47 mmol) was added to
2
a solution of ethyl chloro(methyl)phosphonate (2.00 g, 0.0187 mol)
in anhydrous acetonitrile (20 mL) with stirring on a magnetic
stirrer under argon at 20 C. The stirring was continued until
complete dissolution of MgCl , followed by addition of NaOCN
2
(
2.44 g, 0.037 mol) and stirring for another 2 h at this temperaꢀ
ture. nꢀOctylamine (2.32 g, 0.018 mol) was added to the suspenꢀ
sion obtained, which was stirred for 1 h at 20 C. The mixture
was quenched with DI water (60 mL) and stirred for another 1 h
at this temperature, then it was allowed to stand for 14 h.
A precipitate was filtered off and further treated similarly
to the synthesis of 2 (method B). The yield was 3.95 g (86%),
m.p. 96 C (heptane—chloroform). Found (%): C, 51.75;
H, 9.79; N, 10.17. C H N O P. Calculated (%): C, 51.79;
Nꢀ[Ethoxy(phenyl)phosphoryl]ꢀN´ꢀnꢀoctylurea (3). Finely
powdered anhydrous MgCl (19 mg, 0.20 mmol) was added to
2
a solution of ethyl chloro(phenyl)phosphonate (1.63 g, 8 mmol)
in anhydrous acetonitrile (15 mL) with stirring on a magnetic
stirrer under argon at 20 C. The mixture was stirred until comꢀ
plete dissolution of MgCl , followed by addition of NaOCN
1
2
27
2
3
2
–
1
H, 9.78; N, 10.07. IR, /cm : 1210 (P=O); 1680, 1695 (d, C=O);
420, 3335, 3170, 3095 (NH). P{ H} NMR (c = 0.05 mol L ),
: 29.6 (s). H NMR (c = 0.05 mol L ), : 0.86 (t, 3 H, Me,
JH,H = 6.8 Hz); 1.16—1.33 (m, 10 H, Me(CH ) ); 1.32 (t, 3 H,
CH CH O, JH,H = 7.0 Hz); 1.48 (quint, 2 H, CH CH N,
JH,H = 7.0 Hz); 1.68 (d, 3 H, MeP, JP,H = 17.5 Hz); 3.08—3.23
(1.03 g, 0.016 mol) and stirring for 2 h at 20 C. The suspension
obtained was treated with octylamine (0.85 g, 6.56 mmol) and
stirred for 1 h at 20 C. DI water (30 mL) was added and the
mixture was stirred for another 1 h at this temperature and then
was allowed to stand for 14 h. A precipitate was filtered off
and further treated similarly to the synthesis of compound 2 by
method B. The yield was 2.24 g (77%), m.p. 115.5—116 C.
Found (%): C, 60.04; H, 8.64; N, 8.19; P, 9.08. C H N O P.
3
1
1
–1
3
1
–1

3
2 5
3
3
2
2
2
3
2
(
m, 2 H, CH N); 3.97—4.16 (m, 2 H, CH O); 6.40 (br.s, 1 H,
2
2
2
NHCH ); 7.60 (d, 1 H, NHP(O), J
= 6.8 Hz).
2
P,H
17 29
2
3
–
1
Nꢀ[Methyl(phenoxy)phosphoryl]ꢀN´ꢀnꢀoctylurea (2). Methꢀ
od A. A solution of nꢀoctylamine (0.414 g, 3.2 mmol) in anhyꢀ
drous benzene (2 mL) was added dropwise to a solution of
methyl(phenoxy)phosphoryl isocyanate (7) (0.579 g, 2.9 mmol)
in anhydrous benzene (8 mL) with stirring on a magnetic stirrer
under argon at 20 C, the mixture was stirred for 1 h at this
temperature. The solvent was evaporated in vacuo, the syrupꢀ
like residue was diluted with hexane (10 mL) and stirred for
Calculated (%): C, 59.98; H, 8.59; N, 8.23; P, 9.10. IR, /cm :
3
1
1
1215 (P=O); 1680 (C=O); 3320, 3170, 3090 (NH). P{ H} NMR
–
1
1
–1
(c = 0.05 mol L ), : 16.9 (s). H NMR (c = 0.05 mol L ), : 0.86
3
(t, 3 H, Me, J
= 7.1 Hz); 1.16—1.32 (m, 10 H, Me(CH ) );
1.38 (t, 3 H, CH CH O, JH,H = 7.0 Hz); 1.34 (quint, 2 H,
CH CH CH N, JH,H = 6.9 Hz); 3.15 (ddt, 1 H, CH N,
H,H
2 5
3
3
2
3
2
A
В
В
2
3
3
J
= 13.4 Hz, J
= 6.9 Hz, J
= 13.4 Hz, J
= 5.9 Hz); 3.17 (ddt,
H ,H
CH,H
NH,H
= 7.1 Hz, J
A
B
2
3
3
1 H, CH N, J
= 5.6 Hz);
A
H ,H
CH,H
NH,H
A
B
1
5 min, a precipitate formed was filtered off, washed with hexꢀ
ane on the filter (2×7 mL), and dried in air. The yield was 0.85 g
87%), m.p. 86—87 C. Found (%): C, 58.99; H, 8.28; N, 8.60;
P, 9.40. C H N O P. Calculated (%): C, 58.88; H, 8.34; N, 8.59;
4.14—4.27 (m, 2 H, CH O); 6.94 (br.t, 1 H, CH CH NH);
2 A В
2
7.28 (d, 1 H, NHP(O), J
= 6.5 Hz); 7.44 (dt, 2 H, mꢀPh,
H,P
3
4
3
(
JH,H = 7.5 Hz, J = 4.4 Hz); 7.54 (dtt, 1 H, pꢀPh, J
= 7.4 Hz,
H,P
H,H
4
5
3
JH,H = J
= 1.2 Hz); 7.83 (ddd, 2 H, oꢀPh, J
= 7.7 Hz,
16
27
2
–
3
H,P
H,H
1
3J
4
P, 9.49. IR, /cm : 1235, 1200 (d, P=O); 1695 sh, 1675 (C=O);
3
= 13.8 Hz, J
= 1.4 Hz).
H,P
H,H
31
1
–1
320, 3140, 3090 (NH). P{ H} NMR (c = 0.05 mol L ), : 28.7
Nꢀ[Phenoxy(phenyl)phosphoryl]ꢀN´ꢀnꢀoctylurea (4). Finely
1
–1
(
3
s). H NMR (c = 0.05 mol L ), : 0.88 (t, 3 H, CH CH ,
JH,H = 6.5 Hz); 1.15—1.35 (m, 10 H, Me(CH ) ); 1.42 (quint,
powdered anhydrous MgCl (19 mg, 0.20 mmol) was added to
3
2
2
a solution of phenyl chloro(phenyl)phosphonate (2.00 g,
7.92 mmol) in anhydrous acetonitrile (15 mL) with stirring on
a magnetic stirrer under argon at 20 C. The mixture was stirred
2 5
3
2
H, CH CH CH N, JH,H = 6.4 Hz); 1.83 (d, 3 H, MeP,
2
A
В
2
2
JH,P = 17.8 Hz); 3.09 (ddt, 1 H, CH N, J
JH,H = 6.5 Hz); 3.15 (ddt, 1 H, CH N, J
= 13.2 Hz,
= 13.2 Hz,
В
H ,H
A
B
3
2
until complete dissolution of MgCl (warmed up with hot water
A
H ,H
2
A
B
3J
= 6.8 Hz); 6.01 (br.s, 1 H, CH CH NH); 7.09—7.22 (m,
for 15 min). Then, NaOCN (1.04 g, 0.016 mol) was added and
the mixture was stirred for 10 h at 20 C. The suspension obꢀ
tained was treated with octylamine (0.84 g, 6.5 mmol) and the
mixture was stirred for 1 h at 20 C, quenched with DI water
(30 mL), and stirred for another 1 h at this temperature, then it
was allowed to stand for 14 h. A precipitate was filtered off and
further treated similarly to the synthesis of compound 2 by methꢀ
od B. The yield was 1.60 g (73%), m.p. 145—146 C (hexꢀ
ane—chloroform). Found (%): C, 65.02; H, 7.61; N, 7.21;
P, 7.92. C H N O P. Calculated (%): C, 64.93; H, 7.53;
H,H
A
В
3
3
H, o,pꢀPh); 7.28 (t, 2 H, mꢀPh, J
= 7.8 Hz); 8.09 (d, 1 H,
H,H
2
13
1
–1
NHP(O), J
= 5.6 Hz). C{ H} NMR (c = 0.1 mol L ),
H,P
1

: 13.96 (d, MeP, J
= 134.2 Hz); 14.10 (s, CH CH ); 22.66
C,P 3 2
(
s, MeCH ); 26.77 (s, CH CH N); 29.24 (s, CH (CH ) N);
2 2 2 2 2 3
2
9.27 (s, CH (CH ) N); 29.81 (s, CH (CH ) N); 31.82
2 2 2 2 2 4
3
(
s, MeCH CH ); 39.92 (s, CH N); 121.03 (d, oꢀPh, J = 4.4 Hz);
2 2 2 C,P
5
4
1
1
=
25.26 (d, pꢀPh, J = 2.2 Hz); 129.62 (d, mꢀPh, J = 1.5 Hz);
C,P C,P
2
2
49.71 (d, ipsoꢀPh, J
= 9.5 Hz); 154.93 (d, C=O, J
=
C,P
C,P
2.2 Hz).
Method B. Finely powdered anhydrous MgCl2 (19 mg,
.20 mmol) was added to a solution of phenyl chloro(methyl)ꢀ
2
1
29
2
3
–
1
N, 7.21; P, 7.97. IR, /cm : 1240, 1205 sh (P=O); 1690 (C=O);
3340, 3160, 3095 (NH). 3 P{ H} NMR (c = 0.05 mol L ),
1
1
–1
0

Extraction with phosporylureas
Russ.Chem.Bull., Int.Ed., Vol. 63, No. 1, January, 2014
147
: 15.2 (s). H NMR (c = 0.05 mol L–1), : 0.84 (t, 3 H, Me, 3JH,H
1
=
3. T. A. Mastryukova, O. I. Artyushin, I. L. Odinets, I. G.

=
6.8 Hz); 1.12—1.32 (m, 10 H, Me(CH ) ); 1.38 (quint, 2 H,
Tananaev, Ros. Khim. Zh., 2005, 49, 86 [Mendeleev Chem. J.
(Engl. Transl.), 2005, 49, No. 2].
2
5
3
CH CH CH N,
J
= 6.3 Hz); 3.06 (ddt, 1 H, CH N,
2
A
В
H,H
В
2
3
JHA,HB = 13.2 Hz, J
= 6.5 Hz); 3.12 (ddt, 1 H, CH N,
4. A. M. Rozen, B. V. Krupnov, Russ. Chem. Rev., 1996, 65, 973.
5. A. M. Safiulina, A. G. Matveeva, T. K. Dvoryanchikova,
O. A. Sinegribova, A. M. Tu, D. A. Tatarinov, A. A. Kostin,
V. F. Mironov, I. G. Tananaev, Russ. Chem. Bull. (Int. Ed.),
2012, 61, 392 [Izv. Akad. Nauk, Ser. Khim., 2012, 390].
6. A. M. Safiulina, A. G. Matveeva, T. K. Dvoryanchikova,
O. A. Sinegribova, D. A. Tatarinov, Tsvetnye metally [Nonꢀ
ferrous metals], 2012, No. 3, 73 (in Russian).
H,H
A
2J
= 13.2 Hz, J
3
= 6.6 Hz); 6.63 (br.t, 1 H, CH CH NH);
HA,HB
H,H
A
В
7
7
.10—7.19 (m, 1 H, pꢀPhO); 7.20—7.30 (m, 4 H, o,mꢀPhO);
.45 (dt, 2 H, mꢀPhP, J
3
4
= 7.4 Hz, J = 4.4 Hz); 7.57 (t, 1 H,
H,H
H,P
3
3
pꢀPhP, J
= 7.1 Hz); 7.95 (dd, 2 H, oꢀPhP, J
= 7.4,
H,H
H,H
3
2
JH,P = 14.1 Hz); 8.10 (d, 1 H, NHP(O), J
= 7.2 Hz).
H,P
Solutions were prepared using bidistilled water, CHCl (reꢀ
3
agent grade), arsenazo III (analytical grade), HNO (high purity
3
grade), UO (NO ) •6H O (reagent grade), La(NO ) •6H O
7. A. G. Matveeva, A. M. Tu, A. M. Safiulina, G. V. Bodrin,
E. I. Goryunov, I. B. Goryunova, O. A. Sinegribova, E. E.
Nifant´ev, Russ. Chem. Bull. (Int. Ed.), 2013, 62, 1309 [Izv.
Akad. Nauk, Ser. Khim., 2013, 1309].
8. V. P. Morgalyuk, A. M. Safiulina, I. G. Tananaev, E. I.
Goryunov, I. B. Goryunova, G. N. Molchanova, T. V. Bauliꢀ
na, E. E. Nifant´ev, B. F. Myasoedov, Dokl. Akad. Nauk,
2005, 403, 201 [Dokl. Chem. (Engl. Transl.), 2005, 403, No. 2].
9. I. G. Tananaev, A. A. Letyushov, A. M. Safiulina, I. B.
Goryunova, T. V. Baulina, V. P. Morgalyuk, E. I. Goryunov,
L. A. Gribov, E. E. Nifant´ev, B. F. Myasoedov, Dokl. Akad.
Nauk, 2008, 422, 762 [Dokl. Chem. (Engl. Transl.), 2008,
422, No. 6].
2
3 2
2
3 3
2
(
reagent grade), Nd(NO ) •6H O (reagent grade),
3 3 2
Ho(NO ) •6H O (pure grade), and Yb(NO ) •6H O (pure
3
3
2
3 3
2
grade). Solutions were prepared by the volumetric gravimetric
method. Solution of lanthanide and actinide nitrates were preꢀ
pared by the dissolution of weighed amounts of the corresꢀ
ponding nitrates in 0.01 M HNO . The concentration of the
3
metal nitrate solutions (1 mmol L– ) was refined spectrophotoꢀ
metrically according to the procedure described earlier30 using
a Cary50 Scan (Varian) spectrometer. The concentration of the
1
HNO solutions was determined by potentiometric titration with
3
0
.1 M NaOH using a pH/ion Analyser Radelkisꢀ125 model
OPꢀ300 with the accuracy ±0.01 pH units. The electrode pair
was calibrated using the standard buffer solutions with pH 1.68,
10. E. I. Goryunov, A. M. Safiulina, V. P. Morgalyuk, I. B.
Goryunova, G. N. Molchanova, T. V. Baulina, E. I. Matroꢀ
sov, P. V. Petrovskii, I. G. Tananaev, E. E. Nifant´ev, B. F.
Myasoedov, Russ. Chem. Bull. (Int. Ed.), 2008, 58, 383 [Izv.
Akad. Nauk, Ser. Khim., 2008, 374].
4
.01, and 9.22 (the values at 20 C). The concentration of the
NaOH solution was refined by potentiometric titration with
0
.1 M HCl (fixanal).
Extraction of metal cations was studied using the following
procedure. A solution of nitric acid (1.5 mL) with the concentraꢀ
tion varying from 0.052 to 5.00 mol L–1, a 1 mM solution of
metal nitrate (0.5 mL), and a 0.01 M solution of ligand in CHCl3
11. A. M. Safiulina, A. A. Letyushov, I. G. Tananaev, B. F.
Myasoedov, E. I. Goryunov, I. B. Goryunova, S. A. Smirnoꢀ
va, A. G. Ginzburg, E. E. Nifant´ev, Mendeleev Commun.,
2009, 19, 263.
(
2 mL) were placed into a testꢀtube with a groundꢀglass stopper.
The phases were stirred for 20 min using a Multi RSꢀ60 multiꢀ
rotator, BioSan, 80 rpm. The time of setting the extraction equiꢀ
librium was established by increasing the time of the contact of
phases to 120 min and finding no changes in the distribution
ratios. The phases were separated by centrifugation. After the
phases were separated, the concentration of metals in the aqueꢀ
ous phase was determined using spectrophotometric method.30
Three or more independent trials were carried out for each conꢀ
centration. All the experiments were performed at 20±1 C.
12. E. I. Goryunov, I. B. Goryunova, T. V. Baulina, P. V. Petroꢀ
vskii, E. I. Matrosov, K. A. Lyssenko, M. S. Grigor´ev,
A. M. Safiulina, V. P. Morgalyuk, A. A. Letyushov, I. G. Tananꢀ
aev, E. E. Nifant´ev, B. F. Myasoedov, Ros. Khim. Zh., 2010,
54, 45 [Mendeleev Chem. J. (Engl. Transl.), 2010, 54, No. 3].
13. E. I. Goryunov, E. E. Nifant´ev, B. F. Myasoedov, Pat.
No. 2296768, Byull. isobret. [Invention Bull.], 2007, No. 10
(in Russian).
14. B. N. Laskorin, D. I. Skorovarov, E. A. Filippov, V. V.
Yakshin, Radiokhimiya, 1985, 27, 156 [Sov. Radiochem.
(Engl. Transl.), 1985, 27].
15. F. D. Sokolov, V. V. Brusko, N. G. Zabirov, R. A. Cherkaꢀ
sov, Curr. Org. Chem., 2006, 10, 27.
Distribution ratios (D = [M]org/[M] ) were determined at
aq
–
1
the constant concentrations of the extractant (0.01 mol L in
CHCl ) and metals (0.25 mmol L in aqueous phase).
–
1
3
This work was financially supported by the Russian
Foundation for Basic Research (Project No. 14ꢀ03ꢀ00695ꢀa)
and the Russian Academy of Sciences (Program for Funꢀ
damental Studies of the Presidium of RAS Pꢀ8 "Developꢀ
ment of Methods for Preparation of Chemical Compounds
and Development of New Materials").
16. E. I. Goryunov, G. N. Molchanova, I. B. Goryunova, T. V.
Baulina, P. V. Petrovskii, V. S. Mikhailovskaya, A. G. Buyaꢀ
novskaya, E. E. Nifant´ev, Russ. Chem. Bull. (Int. Ed.), 2005,
5
5, 2626 [Izv. Akad. Nauk, Ser. Khim., 2005, 2543].
7. T. A. Mastryukova, M. I. Kabachnik, Russ. Chem. Rev., 1969,
8, 795.
1
1
3
8. E. I. Matrosov, A. G. Kozachenko, M. I. Kabachnik, Izv.
Akad. Nauk SSSR, Ser. Khim., 1976, 1470 [Bull. Acad. Sci.
USSR, Div. Chem. Sci. (Engl. Transl.), 1976, 25, No. 7];
B. I. Stepanov, B. A. Korolev, A. I. Bokanov, Zh. Obshch.
Khim., 1969, 39, 316 [Russ. J. Gen. Chem. (Engl. Transl.),
1969, 39, No. 7]; E. I. Matrosov, Dr. Sci. Thesis (Chem.),
A. N. Nesmeyanov Institute of Organoelement Comꢀ
pounds, USSR Academy of Sciences, Moscow, 1978, 373 pp.
(in Russian).
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Received November 25, 2013;
in revised form December 11, 2013