ISSN 1070-4280, Russian Journal of Organic Chemistry, 2013, Vol. 49, No. 4, pp. 625–626. © Pleiades Publishing, Ltd., 2013.
Original Russian Text © A.R. Garifzyanov, R.R. Davletshin, N.V. Davletshina, S.A. Koshkin, M.S. Valeeva, R.A. Cherkasov, 2013, published in Zhurnal
Organicheskoi Khimii, 2013, Vol. 49, No. 4, pp. 640–641.
SHORT
COMMUNICATIONS
Dedicated to the 100th Anniversary of Corresponding Member
of the Russian Academy of Sciences A.A. Petrov
Synthesis and Structure of Aminomethylphosphabetaines
A. R. Garifzyanov, R. R. Davletshin, N. V. Davletshina, S. A. Koshkin,
M. S. Valeeva, and R. A. Cherkasov
Kazan (Volga Region) Federal University, ul. Kremlevskaya 18, Kazan, 420008 Tatarstan, Russia
e-mail: rafael.cherkasov@ksu.ru
Received February 25, 2013
DOI: 10.1134/S1070428013040246
It is known that some dialkyl aminoalkylphospho-
nates in solution spontaneously undergo intramolecular
O→N migration of alkyl group with formation of
zwitterionic alkyl ammonioalkylphosphonates which
may be regarded as synthetic analogs of phosphono-
and phospholipids capable of acting as mono- and
multidentate ligands in donor–acceptor complexes
with some Lewis acids [1]. While searching for effi-
cient and selective liquid and membrane extractants for
various substrates, we have developed a new conveni-
ent procedure for the synthesis of phosphabetaines.
This procedure implies N-alkylation of potassium alkyl
aminomethylphosphonates prepared by hydrolysis of
the corresponding dialkyl aminomethylphosphonates
with aqueous sodium hydroxide. Alkyl hydrogen
again into potassium salt by adding an equimolar
amount of 50% aqueous potassium hydroxide.
Quaternization of potassium salts with benzyl
chloride gave zwitterionic ammoniomethylphospho-
nates IV–VI as well shaped crystals, which can be
readily purified by recrystallization from methanol or
ethyl acetate.
The structure of IV–VI was determined on the
1
31
basis of their IR and H and P NMR spectra, and the
structure of ethyl [benzyl(dipropyl)ammoniomethyl]-
phosphonate (IV) was proved by the X-ray diffraction
data. More detailed information on the structure and
properties of new phosphabetaines will be reported
elsewhere. The synthesis of dialkyl aminomethylphos-
phonates was described in [2].
aminomethylphosphonates (RO)(OH)P(O)CH NR′R′
2
Potassium ethyl [(dipropylamino)methyl]phos-
were synthesized in almost quantitative yield (accord-
ing to the 31P NMR data) by the Kabachnik–Fields
reaction [2] and were converted without isolation and
special purification into potassium salts I–III. The
latter were purified by treatment with ethyl acetate;
nonpolar organic impurities were thus removed,
whereas salts I–III did not dissolve. If this procedure
was inefficient, the salts were dissolved in methanol,
and small amount of dilute hydrochloric acid was
added to the solution. Solid impurities were filtered
off, and the alkyl hydrogen phosphonate was converted
phonate (I). Yield 75%, mp 188°C. IR spectrum
–1
(
mineral oil), ν, cm : 1104 (P=O), 1061 (P–O–C).
1
H NMR spectrum (CDCl , 300 MHz), δ, ppm: 0.86 t
3
3
3
(
3H, CH CH , J = 7.28 Hz), 1.23 t (6H, CH , J
=
3
2
HH
3
HH
7
.04 Hz), 1.39–1.52 m (4H, NCH CH ), 2.52–2.65 d.d
2
2
(
2H, PCH ) and t (4H, NCH ); 3.86–3.95 m (OCH ).
2
2
2
31
P NMR spectrum (dioxane, 122.4 MHz): δ 20.4 ppm.
P
Potassium butyl [(dibutylamino)methyl]phos-
phonate (II). Yield 78%, mp 205°C. IR spectrum
–
1
(
mineral oil), ν, cm : 1194 (P=O), 1061 (P–O–C).
1
H NMR spectrum (CDCl , 300 MHz), δ, ppm: 0.95 t
3
3
O
P
R'
O
P
R'
(9H, CH , J = 7.24 Hz), 1.23–1.67 m (12H, CH ),
3
HH
2
PhCH Cl
2
2
RO
K+ –O
N
RO
–O
N
R'
2.57–2.74 t (NCH ), 2.69 d (2H, PCH , J
2
2
PH
=
–
KCl
R'
31
CH Ph
12.80 Hz), 3.81–3.91 m (2H, OCH ). P NMR spec-
2
2
I–III
IV–VI
trum (dioxane, 122.4 MHz): δ 21.3 ppm.
P
Potassium 3-methylbutyl [(dibutylamino)meth-
yl]phosphonate (III). Yield 80%, mp 198°C. IR spec-
I, IV, R = Et, R′ = Pr; II, V, R = R′ = Bu; III, VI, R =
iso-C 11, R′ = Bu.
5
H
6
25
Garifzyanov
