α-Amino acetals containing a phosphonate or phosphine oxide group. Synthesis and reactions with resorcinols

Article abstract of DOI:10.1134/S1070428014040034

New α-amino acetals containing a phosphonate or phosphine oxide group were synthesized by the Kabachnik-Fields reaction in the ternary system amino acetal-paraformaldehyde-dialkyl phosphonate (or dialkylphosphine oxide). Condensation of dialkyl (2,2-dimethoxyethylamino)methylphosphonates with resorcinol and its derivatives in ethanol in the presence of hydrochloric acid, apart from the corresponding 2,2-bis(polyhydroxyphenyl) ethylammonium salts, gave 2,5-bis(polyhydroxyphenyl)-1,4-bis[(dialkoxyphosphoryl)methyl]-piperazines. Dialkyl[(2,2-dimethoxyethylamino)methyl]phosphine oxides (Alk = C ₈H₁₇, C₁₀H₂₁) did not react with resorcinol derivatives under similar conditions, and analogous ammonium salts were obtained by heating the reactants in boiling trifluoroacetic acid.

Full text of DOI:10.1134/S1070428014040034

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2014, Vol. 50, No. 4, pp. 469–477. © Pleiades Publishing, Ltd., 2014.
Original Russian Text © L.I. Vagapova, L.R. Amirova, E.Yu. Pavlova, A.R. Burilov, Yu.K. Voronina, V.V. Syakaev, D.R. Sharafutdinova, I.Kh. Rizvanov,
A.R. Garifzyanov, M.A. Pudovik, 2014, published in Zhurnal Organicheskoi Khimii, 2014, Vol. 50, No. 4, pp. 484–491.
α-Amino Acetals Containing a Phosphonate or Phosphine Oxide
Group. Synthesis and Reactions with Resorcinols
L. I. Vagapovaa, L. R. Amirovab, E. Yu. Pavlovab, A. R. Burilova, Yu. K. Voroninaa,
V. V. Syakaeva, D. R. Sharafutdinovaa, I. Kh. Rizvanova,
A. R. Garifzyanovc, and M. A. Pudovika
a Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center, Russian Academy of Sciences,
ul. Arbuzova 8, Kazan, 420088 Tatarstan, Russia
e-mail: vagapoval@iopc.ru
b Kazan National Research Technological University, ul. Karla Marksa 68, Kazan, 420015 Tatarstan, Russia
c Kazan (Volga Region) Federal University, ul. Kremlevskaya 18, Kazan, 420008 Tatarstan, Russia
Received January 14, 2014
Abstract—New α-amino acetals containing a phosphonate or phosphine oxide group were synthesized by the
Kabachnik–Fields reaction in the ternary system amino acetal–paraformaldehyde–dialkyl phosphonate (or dial-
kylphosphine oxide). Condensation of dialkyl (2,2-dimethoxyethylamino)methylphosphonates with resorcinol
and its derivatives in ethanol in the presence of hydrochloric acid, apart from the corresponding 2,2-bis(poly-
hydroxyphenyl)ethylammonium salts, gave 2,5-bis(polyhydroxyphenyl)-1,4-bis[(dialkoxyphosphoryl)methyl]-
piperazines. Dialkyl[(2,2-dimethoxyethylamino)methyl]phosphine oxides (Alk = C8H17, C10H21) did not react
with resorcinol derivatives under similar conditions, and analogous ammonium salts were obtained by heating
the reactants in boiling trifluoroacetic acid.
DOI: 10.1134/S1070428014040034
Amino acetals have long attracted researchers’ also promising for use in radioactive waste treatment
attention due to their utility in various syntheses [1].
These compounds have been shown to be universal
building blocks in the synthesis of many biologically
important heterocycles and alkaloids [2] and diaryl-
methane derivatives exhibiting a broad spectrum of
pharmacological activity [3].
processes [11].
The goal of the present work was to obtain new
cyclic and acyclic polyphenol structures containing
amino phosphonate (amino phosphine oxide) groups.
For this purpose, we synthesized α-amino acetals func-
tionalized with a phosphonate (phosphine oxide)
group, and studied their condensation with resorcinol
and its derivatives in acid medium.
The condensation of functionally substituted acetals
with resorcinol and its derivatives in acid medium
provides a convenient method for the preparation of
unique linear and cyclic polyphenols such as calix[4]-
resorcinarenes having aminoalkyl [4] and phosphorus-
containing substituents [5] on the lower rim, diaryl-
methane derivatives [6], including those based on
a macrocyclic scaffold [7], and imidazolidin-2-ones
with polyphenol fragments [8].
Phosphorylated acetals IIIa–IIId were prepared by
reaction of aminoacetaldehyde dimethyl acetal (I) with
Scheme 1.
OMe
H2N
+
(CH2O)n + R2PH(O)H
OMe
I
IIa–IId
In continuation of our studies it seemed reasonable
to synthesize acetals containing a phosphorylmethyl-
amino group. Due to their complexing ability, amino
phosphonates and amino phosphine oxides are used as
extractants for rare earth metals [9] and amino acid
carriers in membrane extraction processes [10] and are
R
OMe
PhH
R
P
N
H
–H2O
O
OMe
IIIa–IIId
R = EtO (a), i-PrO (b), C8H17 (c), C10H21 (d).
469

VAGAPOVA et al.
470
Scheme 2.
OH
O
P
R'
R
OH
R
OH
N
N
IIIa, IIIb, HCl, EtOH
OH
H
OH
R'
R'
+
2
H
6′
2′
–2MeOH
O
R'
OH
1′
2′
1′
3′
N
5′
P
R
OH
R
4′
R
6′
4′
HO
OH
A–
HO
P
R
3′
5′
R'
O
IVa–IVc, Va–Vc
VIa–VIc, VIIa–VIIc
OH
R'
OH
IIIc, IIId, CF3COOH, reflux
OH
R'
H
2
H
O
N
P
R
OH
R
HO
OH
A–
R'
VIIIa, VIIIb, IXa–IXc
IV, VI, R = EtO; V, VII, R = i-PrO; VIII, R = C8H17; IX, R = C10H21; R1 = Me (a), H (b), OH (c); A = Cl, CF3COO.
dialkyl phosphonates IIa and IIb or dialkylphosphine
oxides IIc and IId and paraformaldehyde at a ratio
of 1 :1 :1 in the presence of p-toluenesulfonic acid
(Kabachnik–Fields reaction; Scheme 1). The structure
are soluble in alcohols, water, acetone, and DMSO.
They characteristically showed in the 1H NMR spectra
doublets at δ 6.28–6.42 and 6.78–7.10 ppm from the
aromatic protons (5′-H and 6′-H, respectively, a triplet
at δ 4.51–5.1 ppm from the methine proton, and
a doublet at δ 3.48–3.61 ppm from the PCH2N protons
(2JPH = 13.4–14.0 Hz).
1
31
of compounds IIIa–IIId was confirmed by H and P
NMR and IR spectroscopy, MALDI mass spectrom-
31
etry, and elemental analysis. The P NMR spectra of
IIIa–IIId contained a single phosphorus signal at
δP 24 (IIIa, IIIb) or 47 ppm (IIIc, IIId). In the
1H NMR spectra of IIIa–IIId the most informative
were a doublet signal at δ 2.77–2.88 ppm from the
PCH2N methylene protons, a triplet at δ 4.42–
4.47 ppm from the acetal CH proton, and a singlet at
δ 3.3 ppm from the methoxy groups.
Detailed analysis of the reaction mixtures showed
that the main process leading to the formation of
diarylmethane derivatives IV and V is accompanied by
a minor one. In the mass spectrum of the reaction mix-
ture obtained in the reaction of amino phosphonate
IIIa with 2-methylresorcinol, apart from ion peaks with
m/z 440 [M – HCl + H]+ and 462 [M – HCl + Na]+
corresponding to compound IVa, we observed fairly
strong peaks with m/z 631 and 653; analogous pattern
was observed in the mass spectra of other reaction
mixtures (Table 1). The 31P NMR spectrum of the same
reaction mixture contained a major signal at δP 15 ppm
and a less intense signal at δP 19 ppm, their intensity
ratio being 9:1.
The condensation of acetals IIIa and IIIb with
resorcinol and its derivatives was carried out at a reac-
tant ratio of 1:2 in ethanol in the presence of concen-
trated aqueous HCl. The progress of the reactions was
monitored by 31P NMR, and the reaction mixtures were
analyzed by MALDI mass spectrometry. We were the
first to reveal that the reactions of resorcinol, 2-meth-
ylresorcinol, and pyrogallol with phosphorylated
amino acetals IIIa and IIIb in acid medium led to the
formation of diarylmethane derivatives IVa–IVc and
Va–Vc containing polyphenol fragments (Scheme 2).
By varying the reaction conditions (solvent, acid
nature, reactant ratio) we found that products with
m/z 631 (in the reaction with 2-methylresorcinol) and
634 (in the reaction with pyrogallol) separated from
the reaction mixture when the reactions were carried
out at a reactant ratio of 4:1 in ethanol in the presence
Compounds IVa–IVc and Va–Vc were isolated as
light yellow hygroscopic crystalline substances which
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α-AMINO ACETALS CONTAINING A PHOSPHONATE OR PHOSPHINE OXIDE GROUP.
Table 1. MALDI mass spectra of reaction mixtures, m/z
471
Reactants
IV, V
VI, VII
2-Methylresorcinol + IIIa
Resorcinol + IIIa
440 [M – HCl + H]+, 462 [M – HCl + Na]+
412 [M – HCl + H]+, 434 [M – HCl + Na]+
443 [M – HCl + H]+, 465 [M – HCl + Na]+
468 [M – HCl + H]+, 490 [M – HCl + Na]+
440 [M – HCl + H]+, 462 [M – HCl + Na]+
472 [M – HCl + H]+, 494 [M – HCl + Na]+
631 [M1 + H]+, 653 [M1 + Na]+
603 [M1 + H]+, 625 [M1 + Na]+
634 [M1 + H]+, 656 [M1 + Na]+
686 [M1 + H]+, 709 [M1 + Na]+
659 [M1 + H]+, 681 [M1 + Na]+
691 [M1 + H]+, 713 [M1 + Na]+
Pyrogallol + IIIa
2-Methylresorcinol + IIIb
Resorcinol + IIIb
Pyrogallol + IIIb
of HCl. In this case, the yield of these products was
higher, and their isolation was easier. On the basis of
Br···N distance is 3.251(5) Å, which is shorter by
0.15 Å than the sum of the van der Waals radii of the
bromine and nitrogen atoms. This contact is the only
one connecting the bromine atom with one molecule
VIa, whereas the other molecule of VIa and 2-methyl-
resorcinol molecule are linked to the bromine atom
through hydrogen bonds.
1
the NMR data (including COSY, 2D H–13C HSQC,
1
and 2D H–13C HMBC experiments), mass spectra,
and elemental analyses, the minor products were
assigned the structure of phosphorus-containing piper-
azines VIa and VIc.
Unlike ammonium salts IVa–IVc and Va–Vc, com-
pounds VIa and VIc displayed in the 1H NMR spectra
strongly broadened signals from the methylene protons
in the piperazine ring (δ 3.00–3.33 ppm), as well as
from the CH protons (δ 4.50–4.89 ppm), and
the PCH2N proton signals appeared as doublets at
δ 3.63–3.88 ppm.
The crystal structure of the complex is represented
by alternating layers made up of molecules VIa and
2-methylresorcinol, which are parallel to the a0b
crystallographic plane, and H3O+ and Br– ions reside
between molecules VIa. No direct interaction was
detected between molecules of VIa and 2-methyl-
resorcinol, while the layers are linked to each other
The structure of piperazine derivatives VIa and VIc
was unambiguously proved by X-ray analysis of the
molecular complex formed by compound VIa with
2-methylresorcinol, hydrogen bromide, and water. This
complex was formed after prolonged storage (7 days)
of a solution of 2-methylresorcinol and amino acetal
IIIa in aqueous HBr at room temperature. According
to the X-ray diffraction data (see figure), molecule VIa
consists of a piperazine ring, two phosphonate frag-
ments linked to the piperazine nitrogen atoms through
methylene spacers, and two 2,4-dihydroxy-3-methyl-
phenyl substituents. Apart from molecules VIa, those
of 2-methylresorcinol, water, and hydrogen bromide
are present in crystal. The bond lengths and bond and
torsion angles in molecule VIa do not differ from the
corresponding standard values. The central piperazine
fragment adopts a boat conformation. The phosphorus
atoms have tetrahedral configuration with the torsion
angles O1P1O2 116.7(4), O1P1O3 115.3(4), and O1P1C4
114.5(3)°.
O10
C9
C10
C11
C8
C18
C17
O3
P1
C13
O1
C7
C6
C12
O12
C4
C14
C15
N5
O2
C16
Molecules of the complex in crystal are packed due
mainly to classical hydrogen bonds (Table 2). In
addition, a shortened intermolecular contact between
the bromine and nitrogen atoms should be noted; the
Structure of the molecule of 1,4-bis[(diethoxyphosphoryl)-
methyl]-2,5-bis(2,4-dihydroxy-3-methylphenyl)piperazine
(VIa) in crystal according to the X-ray diffraction data.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 50 No. 4 2014

VAGAPOVA et al.
472
Table 2. Hydrogen bonds formed by molecules VIa in crystal
Hydrogen bond
Symmetry operation
D–H, Å
D···A, Å
∠DHA, deg
O10···H10···O4
O12···H12···Br1
O17···H17···Br1
O21···H21···O4
O4···H411···Br1
O4···H412···O1
C4 ···H41···O10
C13 ···H133···O10
C14 ···H142···O12
C15 ···H152···O21
C23 ···H231···O17
x, 1 + y, z
0.82
0.82
0.82
0.82
0.87
0.87
0.97
0.96
0.97
0.97
0.96
2.626(8)
3.283(5)
167
144
160
136
144
180
150
109
119
175
110
–
1 – x, 1 – y, 1 – z
3.394(9)
x, y, 1 + z
03.002(12)
3.292(6)
–
2 – x, 1 – y, 1 – z
2.715(9)
1 – x, 2 – y, 1 – z
3.443(8)
–
02.769(10)
2.976(8)
–
2 – x, 1 – y, 2 – z
03.390(18)
02.674(19)
–
through interactions of both organic components with
H3O+ cations and Br– anions.
dered. Therefore, a larger amount of acid is required to
effect the condensation.
Thus, we were the first to reveal that reactions of
resorcinol, 2-methylresorcinol, and pyrogallol with
phosphorylated amino acetals IIIa and IIIb in the
presence of hydrochloric acid lead to the formation of
[2,2-bis(polyhydroxyphenyl)ethyl](dialkoxyphos-
phorylmethyl)ammonium chlorides IV and V as the
major products and phosphorylated polyhydroxy-
phenyl-substituted piperazines VI and VII as minor
ones. Among the latter, we succeeded in isolating only
those formed in the reactions of acetal IIIa with
2-methylresorcinol and pyrogallol; piperazine deriva-
tives VIb and VIIa–VIIc were detected in the reaction
mixtures by MALDI mass spectrometry.
However, it was impossible to increase the amount
of acid catalyst (aqueous HCl) because of the low
solubility of amino acetals IIIc and IIId in water. No
condensation products were formed when the reaction
was carried out in a nonpolar solvent (chloroform,
benzene, toluene) in the presence of trifluoroacetic
acid. We succeeded in obtaining the desired products
only by heating acetals IIIc and IIId with resorcinol
and its derivatives in boiling trifluoroacetic acid
(Scheme 2). The results of a number of experiments
showed that 4-fold excess of polyphenol with respect
to amino acetal III ensured formation of condensation
products VIIIa, VIIIb, and IXa–IXc in 45–55% yield;
piperazine derivatives like VI (VII) were not detected
in the reaction mixtures.
Diarylmethane derivatives like IV and V attract
interest as multidentate ligands [12] and building
blocks for the synthesis of new macrocyclic com-
pounds [5], and piperazine derivatives VI and VII are
promising as biologically active compounds [13].
Compounds VIIIa, VIIIb, and IXa–IXc were
isolated as white powders with low melting points,
which were soluble in chloroform, alcohols, acetone,
and benzene. Their structure was confirmed by the IR,
The structure of the condensation products formed
in reactions with functionalized acetals is largely
determined by the nature of the reactants and reaction
conditions [4–6]. Amino acetals IIIc and IIId having
dialkylphosphorylmethyl substituents (Alk = C8H17,
C10H21) on the nitrogen atom failed to react with poly-
phenols under the above conditions (ethanol–HCl).
The 31P NMR spectra of the reaction mixtures con-
tained signals in the region δ 53–55 ppm, indicating
concurrent protonation of the P=O group in the pres-
ence of HCl. As a result, the catalyst (HCl) is deac-
tivated, and generation of carbocations necessary for
electrophilic substitution in the aromatic ring is hin-
1
13
31P, H, and C NMR, and MALDI mass spectra and
elemental analyses.
To conclude, we have revealed a new path in the
reaction of phosphorylated α-amino acetals with resor-
cinol and its derivatives in ethanol in the presence of
hydrochloric acid, which leads to the formation of
phosphorus-containing piperazine derivatives in ad-
dition to products of the diarylmethane series.
Analogous amino acetals containing a phosphine oxide
fragment exhibit a lower reactivity toward resorcinol
derivatives. Dialkyl(2,2-dimethoxyethylaminomethyl)-
phosphine oxides (Alk = C8H17, C10H21) do not form
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 50 No. 4 2014

α-AMINO ACETALS CONTAINING A PHOSPHONATE OR PHOSPHINE OXIDE GROUP.
473
condensation products in ethanol under catalysis with
concentrated aqueous HCl, and heating of the reactants
in boiling trifluoroacetic acid is necessary to obtain the
corresponding diarylmethane derivatives.
of paraformaldehyde, and 0.01 g of p-toluenesulfonic
acid in 20 mL of benzene was heated for 6 h under
reflux in a flask equipped with a Dean–Stark trap.
When the reaction was complete, 0.12 g of potassium
carbonate was added, the mixture was heated under
reflux for an additional 10 min and cooled, and the
precipitate was filtered off. The organic layer was
washed with three portions of water and dried over
MgSO4, and the solvent was distilled off. Yield 2.05 g
(93%). IR spectrum, ν, cm–1: 3294 br (NH), 1263 s
EXPERIMENTAL
1
The H and 13C NMR spectra were recorded on
a Bruker Avance-600 spectrometer at 600.1 and
150.9 MHz, respectively; the chemical shifts were
measured relative to the residual proton and carbon
1
(P=O). H NMR spectrum (CDCl3), δ, ppm: 0.85 t
31
signals of the deuterated solvents. The P NMR spec-
(6H, CH3, J = 6.9 Hz), 1.25 br.s (16H, CH2), 1.36 m
(4H, CH2), 1.53 m (4H, CH2), 1.70 m (4H, CH2P),
2.77 d (2H, NCH2, J = 5.4 Hz), 2.92 d (2H, PCH2N,
J = 7.9 Hz), 3.34 s (6H, OCH3), 4.32 t (1H, CH, J =
5.4 Hz). 31P NMR spectrum (CDCl3): δP 47.64 ppm.
Mass spectrum, m/z: 392 [M + H]+, 414 [M + Na]+,
430 [M + K]+. Found, %: C 64.19; H 11.84; N 3.54;
P 7.98; C21H46NO3P. Calculated, %: C 64.35; H 11.86;
N 3.52; P 7.99.
tra were recorded on a Bruker Avance II-400 instru-
ment at 161.9 MHz using 85% phosphoric acid as
external reference. The IR spectra (4000–400 cm–1)
were obtained on a Bruker Vector-22 spectrometer. The
MALDI-TOF mass spectra were recorded on a Bruker
Ultraflex III instrument using plastic and metal targets
and 2,5-dihydroxybenzoic acid as matrix.
The X-ray diffraction data for a single crystal of
the complex of VIa with 2-methylresorcinol, HBr, and
H2O were acquired on a Bruker SMART Apex II dif-
fractometer (λMoKα radiation, λ 0.71073 Å; graphite
monochromator). The structure was solved by the
direct method using SHELXS software package [14].
The positions of non-hydrogen atoms were refined first
in isotropic and then in anisotropic approximation
using SHELXL-97 [15]. Hydrogen atoms attached to
carbons were placed in calculated positions. All cal-
culations were carried out using WinGX [16] and
APEX2 [17]. The molecular structure was plotted with
the aid of PLATON [18]. The complex crystallized in
triclinic crystal system; C42H64Br2N2O16P2. Unit cell
parameters (20°C): a = 9.1050(9), b = 11.2785(11), c =
13.8547(13) Å; α = 81.6740(10), β = 73.2540(10), γ =
70.6250(10)°; V = 1283.3(2) Å3; Z = 1, dcalc = 1.391 g×
cm–3; space group P-1; μMo = 1.707 cm–1. Intensities of
4958 reflections were measured; 3258 reflections were
characterized by I ≥ 2σ(I). Final divergence factors
R = 0.0549, Rw = 0.1538. The X-ray diffraction data
for compound VIa were deposited to the Cambridge
Crystallographic Data Centre (entry no. CCDC
982639).
Didecyl[(2,2-dimethoxyethyl)aminomethyl]-
phosphine oxide (IIId) was synthesized in a similar
way from 1.63 g (5.39 mmol) of didecylphosphine
oxide (IId), 0.56 g (5.33 mmol) of aminoacetaldehyde
dimethyl acetal, and 0.16 g (5.33 mmol) of paraformal-
dehyde. Yield 2.3 g (95%), mp 40–42°C. IR spectrum,
1
ν, cm–1: 3283 br (NH), 1258 s (P=O). H NMR spec-
trum (CDCl3), δ, ppm: 0.88 t (6H, CH3, J = 7.1 Hz),
1.24 br.s (24H, CH2), 1.39–1.42 m (4H, CH2), 1.57 m
(4H, CH2), 1.73 m (4H, CH2P), 2.82 d (2H, NCH2, J =
5.4 Hz), 2.96 d (2H, PCH2N, J = 7.9 Hz), 3.38 s (6H,
OCH3), 4.47 t (1H, CH, J = 5.4 Hz). 31P NMR spec-
trum (CDCl3): δP 47.6 ppm. Mass spectrum, m/z: 448
[M + H]+, 470 [M + Na]+, 487 [M + K]+. Found, %:
C 67.07; H 12.05; N 3.14; P 6.95. C25H54NO3P. Cal-
culated, %: C 67.11; H 12.08; N 3.13; P 6.94.
Compounds IVa–IVc, VIa, and VIIc (general
procedure). a. A mixture of 5.65 mmol of the corre-
sponding polyphenol and 0.70 g (2.75 mmol) of amino
phosphonate IIIa in 5 mL of ethanol was cooled to
5°C, 1.5 mL of aqueous HCl was added dropwise
under vigorous stirring, and the mixture was stirred for
1 h at room temperature and heated for 4–6 h at 55–
60°C. When the reaction was complete, a part of the
solvent was evaporated under reduced pressure (water-
jet pump), and the precipitate (compound VIa or VIc)
was filtered off, washed with acetone, and dried under
reduced pressure (water-jet pump). The filtrate was
evaporated, the oily residue was dissolved in water, the
solution was extracted twice with diethyl ether, the
aqueous layer was evaporated under reduced pressure
Phosphorylated α-amino acetals IIIa and IIIb were
synthesized according to the procedures described
in [19, 20].
[(2,2-Dimethoxyethyl)aminomethyl]dioctylphos-
phine oxide (IIIc). A mixture of 1.5 g (5.47 mmol) of
dioctylphosphine oxide (IIc), 0.57 g (5.42 mmol) of
aminoacetaldehyde dimethyl acetal, 0.16 g (5.33 mmol)
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 50 No. 4 2014

VAGAPOVA et al.
474
(water-jet pump), and the precipitate (compound IVa–
IVc) was dried in a vacuum desiccator over P2O5 until
constant weight.
(IVc). Yield 1.27 g (69%, a), 5.12 g (40%, b); mp 148–
150°C. IR spectrum, ν, cm–1: 3420 br (OH), 1626 w
(C=Carom), 1215 s (P=O), 1045 s (POC). H NMR
1
spectrum (acetone-d6), δ, ppm: 1.25 t (6H, CH3, J =
7.1 Hz), 3.51 d (2H, PCH2, J = 14.0 Hz), 3.68 d (2H,
NCH2, J = 7.8 Hz), 4.11 m (4H, OCH2), 4.82 t (1H,
b. Amino acetal IIIa, 3 g (11 mmol), was added
dropwise to a mixture of 36.40 mmol of the corre-
sponding polyphenol, 30 mL of ethanol, and 8 mL of
aqueous HCl, and the mixture was heated for 4 h at
60–75°C and left to stand for 24 h. The precipitate
(compound VIa or VIc) was filtered off and dried
under reduced pressure (water-jet pump) until constant
weight. The filtrate was evaporated under reduced
pressure, the oily residue was dissolved in water, the
solution was extracted with diethyl ether and methy-
lene chloride, the aqueous layer was separated by
decanting and evaporated under reduced pressure, and
the residue (compound IVa or IVc) was dried under
reduced pressure.
3
CH, J = 7.8 Hz), 6.42 d (2H, 5′-H, J = 8.6 Hz),
3
13
7.10 br.s (2H, 6′-H, J = 8.6 Hz). C NMR spectrum
(acetone-d6), δC, ppm: 14.8 (CH3), 24.9 (CH), 45.4
(PCH2N), 60.3 (CH2), 62.0 (OCH2), 110.4 (C5′), 123.7
(C6′), 126.8 (C1′), 136.5 (C3′), 146.2 (C2′), 147.6 (C4′).
31P NMR spectrum (acetone-d6): δP 16.9 ppm. Mass
spectrum, m/z: 444 [M – HCl + H]+, 466 [M – HCl +
Na]+, 482 [M – HCl + K]+. Found, %: C 47.15; H 5.73;
Cl 7.42; N 2.79; P 6.43. C19H26NO9P·HCl. Calculated,
%: C 47.55; H 5.67; Cl 7.39; N 2.92; P 6.45.
1,4-Bis[(diethoxyphosphoryl)methyl]-2,5-bis(2,4-
dihydroxy-3-methylphenyl)piperazine (VIa). Yield
0.10 g (12%, a), 0.62 g (16.7%, b); mp 205–208°C. IR
spectrum, ν, cm–1: 3426, 3201 br (OH); 1604 m
(C=Carom); 1253 m (P=O); 1080, 1013 s (POC).
1H NMR spectrum (D2O), δ, ppm: 1.25 t (12H, CH3,
J = 6.9 Hz), 2.13 s (6H, 3′-CH3), 3.11–3.33 m (4H,
NCH2), 3.88 d (4H, PCH2, J = 16.4 Hz), 4.06–4.13 m
(8H, OCH2), 4.89 br.s (2H, CH), 6.42 d (2H, 5′-H, 3J =
8.4 Hz), 7.10 br.s (2H, 6′-H). 31P NMR spectrum
(D2O): δP 19.83 ppm. Mass spectrum, m/z: 631 [M +
H]+, 653 [M + Na]+, 669 [M + K]+. Found, %: C 52.85;
H 7.05; N 4.46; P 9.84. C28H44N2O10P2. Calculated, %:
C 53.33; H 7.03; N 4.44; P 9.82.
N-[2,2-Bis(2,4-dihydroxy-3-methylphenyl)ethyl]-
N-[(diethoxyphosphoryl)methyl]ammonium
chloride (IVa). Yield 0.95 g (74%, a), 2.53 g (45%, b);
mp 180–182°C. IR spectrum, ν, cm–1: 3406, 3259 br
(OH); 1609 s (C=Carom); 1232 s (P=O), 1019, 1073 s
1
(POC). H NMR spectrum (D2O), δ, ppm: 1.21 t (6H,
CH3, J = 6.9 Hz), 2.00 s (6H, 3′-CH3), 3.48 d (2H,
PCH2, J = 14.0 Hz), 3.67 d (2H, NCH2, J = 7.9 Hz),
4.06–4.13 m (4H, OCH2), 4.89 t (1H, CH, J = 7.6 Hz),
3
6.42 d (2H, 5′-H, J = 8.6 Hz), 6.78 d (2H, 6′-H, J =
8.6 Hz). 31P NMR spectrum (D2O): δP 16.83 ppm.
Mass spectrum, m/z: 440 [M – HCl + H]+, 462 [M –
HCl + Na]+, 478 [M – HCl + K]+. Found, %: C 52.85;
H 6.69; Cl 7.45; N 2.49; P 6.43. C21H30NO7P·HCl.
Calculated, %: C 53.00; H 6.57; Cl 7.45; N 2.94;
P 6.51.
1,4-Bis[(diethoxyphosphoryl)methyl]-2,5-bis-
(2,3,4-trihydroxyphenyl)piperazine (VIIc). Yield
0.15 g (12%, a), 0.70 g (19%, b); mp 199–201°C.
IR spectrum, ν, cm–1: 3418, 3243 br (OH); 1628 m
(C=Carom); 1213 m (P=O); 1048, 1019 s (POC).
1H NMR spectrum (D2O) δ, ppm: 1.16 t (12H, CH3,
J = 6.9 Hz), 3.00–3.26 m (4H, NCH2), 3.63 d (4H,
PCH2, J = 11.4 Hz), 3.88–3.92 m (8H, OCH2),
N-[2,2-Bis(2,4-dihydroxyphenyl)ethyl]-N-[(di-
ethoxyphosphoryl)methyl]ammonium chloride
(IVb). Yield 0.72 g (59%), mp 140–141°C. IR spec-
trum, ν, cm–1: 3422, 3243 br (OH); 1620 s (C=Carom);
1227 s (P=O); 1019, 1039 s (POC). 1H NMR spectrum
(CD3OD), δ, ppm: 1.36 t (6H, CH3, J = 6.9 Hz), 3.54 d
(2H, PCH2, J = 14.0 Hz), 3.79 d (2H, NCH2, J =
7.6 Hz), 4.18–4.23 m (4H, OCH2), 6.28 d (2H, 5′-H,
3JHH = 8.2 Hz), 6.40 s (2H, 3′-H), 6.93 d (2H, 6′-H, J =
8.2 Hz), 8.90 br.s (4H, OH). 31P NMR spectrum
(CD3OD): δP 16.62 ppm. Mass spectrum, m/z: 412
[M – HCl + H]+, 434 [M – HCl + Na]+, 451 [M –
HCl + K]+. Found, %: C 50.35; H 6.09; Cl 7.86;
N 3.19; P 6.94. C19H26NO7P·HCl. Calculated, %:
C 50.96; H 6.08; Cl 7.92; N 3.13; P 6.92.
3
4.55 br.s (2H, CH), 6.39 d (2H, 5′-H, J = 8.4 Hz),
3
6.81 d (2H, 6′-H, J = 8.4 Hz). 13C NMR spectrum
(D2O), δC, ppm: 16.0 (CH3), 47.4 (NCH2), 57.1
(PCH2NH), 59.3 (CH), 62.0 (OCH2), 107.6 (C5′), 117.5
(C6′), 120.8 (C1′), 132.9 (C3′), 145.1 (C2′), 146.6 (C4′).
31P NMR spectrum (D2O): δP 20.01 ppm. Mass spec-
trum, m/z: 635 [M + H]+, 657 [M + Na]+, 673 [M + K]+.
Found, %: C 48.75; H 6.41; N 4.38; P 9.82.
C26H40N2O12P2. Calculated, %: C 49.21; H 6.31;
N 4.42; P 9.78.
N-[2,2-Bis(2,3,4-trihydroxyphenyl)ethyl]-N-[(di-
Compounds Va–Vc (general procedure). A mix-
ethoxyphosphoryl)methyl]ammonium chloride
ture of 7.06 mmol of the corresponding polyphenol
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 50 No. 4 2014

α-AMINO ACETALS CONTAINING A PHOSPHONATE OR PHOSPHINE OXIDE GROUP.
475
and 0.50 g (1.76 mmol) of amino phosphonate IIIb in
5 mL of ethanol was cooled to 10°C, 1 mL of aqueous
HCl was added dropwise under continuous stirring,
and the mixture was stirred for 2 h at room temperature
and heated for 4 h at 60°C. The solvent was distilled
off on a rotary evaporator, the residue was ground with
diethyl ether, and the precipitate was filtered off and
dried in a vacuum desiccator over P2O5 until constant
weight.
H]+, 494 [M – HCl + Na]+. Found, %: C 49.55; H 6.16;
Cl 7.06; N 2.73; P 6.03. C21H30NO9P·HCl. Calculated,
%: C 49.65; H 6.11; Cl 6.99; N 2.76; P 6.10.
Compounds VIIIa, VIIIb, and IXa–IXc (general
procedure). A mixture of 4 mmol of the corresponding
polyphenol and 1 mmol of amino phosphine oxide IIIc
or IIId in 4 mL of trifluoroacetic acid was heated for
8 h under reflux. When the reaction was complete,
trifluoroacetic acid was distilled off on a rotary evap-
orator, the residue was ground with diethyl ether, and
the precipitate was filtered off and dried in a vacuum
desiccator over P2O5 until constant weight.
N-[2,2-Bis(2,4-dihydroxy-3-methylphenyl)ethyl]-
N-[(diisopropoxyphosphoryl)methyl]ammonium
chloride (Va). Yield 0.55 g (66%), mp 76–78°C. IR
spectrum, ν, cm–1: 3415 s (OH), 1609 m (C=Carom),
N-[2,2-Bis(2,4-dihydroxy-3-methylphenyl)ethyl]-
N-[(dioctylphosphoryl)methyl]ammonium tri-
fluoroacetate (VIIIa). Yield 0.36 g (53%), mp 93–
95°C. IR spectrum, ν, cm–1: 3423 br (OH), 1672 s
1
1199 m (P=O), 1073 s (POC). H NMR spectrum
(D2O), δ, ppm: 1.25 d and 1.28 d (6H each, CH3, J =
6.2 Hz), 2.05 s (6H, 3′-CH3), 3.50 d (2H, NCH2P, J =
13.9 Hz), 3.76 d (2H, NCH2, J = 7.9 Hz), 4.73 m (2H,
OCH), 4.94 t (1H, CH, J = 7.9 Hz), 6.50 d (2H, 5′-H,
1
(C=O), 1610 s (C=Carom), 1203 m (P=O). H NMR
spectrum (acetone-d6), δ, ppm: 0.91 t (6H, CH3, J =
6.32 Hz), 1.30 br.s (16H, CH2), 1.41 m (4H, CH2),
1.57 m (4H, CH2CH2P), 1.98 m (4H, CH2P), 2.13 s
(6H, 3′-CH3), 3.55 d (2H, PCH2N, J = 6.2 Hz), 3.86 d
(2H, CH2N, J = 7.6 Hz), 5.14 t (1H, CH, J = 7.6 Hz),
31
J = 8.5 Hz), 6.88 d (2H, 6′-H, J = 8.5 Hz). P NMR
spectrum (D2O): δP 14.91 ppm. Mass spectrum, m/z:
468 [M – HCl + H]+, 490 [M – HCl + Na]+. Found,
%: C 54.52; H 6.99; Cl 7.02; N 2.82; P 6.24.
C23H34NO7P·HCl. Calculated, %: C 54.81; H 6.95;
Cl 7.05; N 2.78; P 6.16.
3
3
6.41 d (2H, 5′-H, J = 8.4 Hz), 6.85 d (2H, 6′-H, J =
8.4 Hz). 13C NMR spectrum (acetone-d6), δC, ppm:
7.9 (3′-CH3), 20.5–31.1 [(CH2)7P], 26.6 d (CH2P, J =
66.3 Hz), 34.6 (CH), 41.9 d (PCH2NH, J = 59.7 Hz),
52.3 (NCH2), 106.9 (C5′), 111.9 (C3′), 115.5 q (CF3, J =
294.0 Hz), 118.3 (C1′), 124.5 (C6′), 152.7 (C2′), 154.6
N-[2,2-Bis(2,4-dihydroxyphenyl)ethyl]-N-[(diiso-
propoxyphosphoryl)methyl]ammonium chloride
(Vb). Yield 0.45 g (58%), mp 70–73°C. IR spectrum,
ν, cm–1: 3271 br (OH), 1614 m (C=Carom), 1220 m
1
31
(C4′), 160.5 q (C=O, J = 40.0 Hz). P NMR spectrum
(P=O), 1074 s (POC). H NMR spectrum (D2O) δ,
ppm: 1.30 d and 1.31 d (6H each, CH3, J = 6.0 Hz),
3.61 d (2H, NCH2P, J = 13.4 Hz), 3.89 d (2H, NCH2,
J = 7.4 Hz), 4.78 m (2H, OCH), 4.96 t (1H, CH, J =
(acetone-d6): δP 46 ppm. Mass spectrum, m/z: 575 [M –
CF3COOH + H]+, 598 [M – CF3COOH + Na]+, 614
[M – CF3COOH + K]+. Found, %: C 59.14; H 7.99;
N 2.83; P 4.91. C33H54NO5P·CF3COOH. Calculated,
%: C 59.27; H 7.97; N 2.87; P 5.02.
3
4
7.4 Hz), 6.29 d.d (2H, 5′-H, J = 8.3, J = 2.4 Hz),
4
6.56 d (2H, 3′-H, J = 2.4 Hz), 6.94 d (2H, 6′-H, J =
8.3 Hz). 31P NMR spectrum (D2O): δP 16.0 ppm. Mass
spectrum, m/z: 440 [M – HCl + H]+, 462 [M – HCl +
Na]+. Found, %: C 52.72; H 6.52; Cl 7.44; N 2.90;
P 6.48. C21H30NO7P·HCl. Calculated, %: C 52.9;
H 6.52; Cl 7.47; N 2.94; P 6.52.
N-[2,2-Bis(2,4-dihydroxyphenyl)ethyl]-N-[(di-oc-
tylphosphoryl)methyl]ammonium trifluoroacetate
(VIIIb). Yield 0.30 g (41%), mp 110–112°C. IR spec-
trum, ν, cm–1: 3436 br (OH), 1672 v.s (C=O), 1615 s
1
(C=Carom), 1205 m (P=O). H NMR spectrum
N-[2,2-Bis(2,3,4-trihydroxyphenyl)ethyl]-N-[(di-
isopropoxyphosphoryl)methyl]ammonium chloride
(Vc). Yield 0.56 g (62%), mp 73–75°C. IR spectrum,
ν, cm–1: 3300 br (OH), 1605 m (C=Carom), 1208 m
(acetone-d6), δ, ppm: 0.89 br.s (6H, CH3), 1.30 br.s
(20H, CH2), 1.43–1.47 m (4H, CH2), 1.58–1.62 m (4H,
CH2P), 3.53 br.s (2H, PCH2N), 3.80 d (2H, CH2N, J =
3
6.7 Hz), 5.07 br.s (1H, CH), 6.30 d (2H, 5′-H, J =
1
(P=O), 1061 s (POC). H NMR spectrum (D2O), δ,
8.4 Hz), 6.57 s (2H, 3′-H), 6.96 d (2H, 6′-H, J =
8.4 Hz). 31P NMR spectrum (acetone-d6): δP 48.11 ppm.
Mass spectrum, m/z: 548 [M – CF3COOH + H]+, 570
[M – CF3COOH + Na]+, 586 [M – CF3COOH + K]+.
Found, %: C 59.84; H 7.69; N 2.06; P 4.65.
C31H50NO5P·CF3COOH. Calculated, %: C 59.90;
H 7.77; N 2.12; P 4.68.
ppm: 1.26 d and 1.27 d (6H each, CH3, J = 6.2 Hz),
3.51 d (2H, NCH2P, J = 13.8 Hz), 3.76 d (2H, NCH2,
J = 7.9 Hz), 4.74 m (2H, OCH), 4.86 t (1H, CH, J =
3
7.9 Hz), 6.47 d (2H, 5′-H, J = 8.5 Hz), 6.62 d
(2H, 6′-H, J = 8.5 Hz). 31P NMR spectrum (D2O):
δP 14.93 ppm. Mass spectrum, m/z: 472 [M – HCl +
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 50 No. 4 2014

VAGAPOVA et al.
476
N-[2,2-Bis(2,4-dihydroxy-3-methylphenyl)ethyl]-
1.28 br.s (24H, CH2), 1.39 m (4H, CH2), 1.59 m (4H,
CH2CH2P), 1.95 m (4H, CH2P), 3.78 d (2H, PCH2N,
J = 6.1 Hz), 3.93 d (2H, CH2N, J = 7.6 Hz), 5.06 t (1H,
CH, J = 7.6 Hz), 6.37 d (2H, 5′-H, 3J = 8.4 Hz), 6.51 d
N-[(didecylphosphoryl)methyl]ammonium tri-
fluoroacetate (IXa). Yield 0.39 g (52%), mp 160–
162°C. IR spectrum, ν, cm–1: 3308 br (OH), 1676 s
1
3
(C=O), 1608 s (C=Carom), 1200 m (P=O). H NMR
(2H, 6′-H, J = 8.4 Hz), 7.97 s (2H, OH). 13C NMR
spectrum (acetone-d6), δ, ppm: 0.89 t (6H, CH3, J =
6.9 Hz), 1.30 br.s (24H, CH2), 1.41 br.s (4H, CH2),
1.58 m (4H, CH2CH2P), 1.98 m (4H, CH2P), 2.10 s
(6H, 3′-CH3), 3.55 d (2H, PCH2N, J = 6.2 Hz), 3.87 d
(2H, CH2N, J = 7.4 Hz), 5.14 t (1H, CH, J = 7.4 Hz),
6.43 d (2H, 5′-H, J = 8.4 Hz), 6.85 d (2H, 6′-H, J =
8.4 Hz). 13C NMR spectrum (acetone-d6), δC, ppm: 7.9
(3′-CH3), 13.0 (CH3), 20.5–30.3 [(CH2)7P], 26.5 d
(CH2P, J = 66.0 Hz), 34.8 (CH), 41.9 d (PCH2N, J =
60.8 Hz), 52.3 (CH2N), 106.9 (C5′), 111.9 (C3′), 115.5 q
(CF3, J = 294.0 Hz), 118.5 (C1′), 124.6 (C6′), 152.7
(C2′), 154.5(C4′), 160.1 q (C=O, J = 40.0 Hz). 31P NMR
spectrum (acetone-d6): δP 47.07 ppm. Mass spectrum,
m/z: 632 [M – CF3COOH + H]+, 654 [M – CF3COOH +
Na]+, 670 [M – H + K]+. Found, %: C 62.65; H 8.48; N
7.87; P 4.43. C37H62NO5P·CF3COOH. Calculated, %:
C 62.81; H 8.45; N 7.57; P 4.16.
spectrum (acetone-d6), δC, ppm: 13.0 (CH3), 21.9–31.2
[(CH2)7P], 26.6 (CH2P, J = 66.3 Hz), 35.1 (CH), 42.1
(PCH2N, J = 59.0 Hz), 53.3 (NCH2), 106.9 (C5′),
115.2 q (CF3, J = 291.0 Hz), 118.6 (C1′), 125.5 (C6′),
132.2 (C3′), 144.5 (C2′), 145.4 (C4′), 159.7 q (C=O, J =
36.6 Hz). 31P NMR spectrum (acetone-d6): δP 51.7 ppm.
Mass spectrum, m/z: 636 [M – CF3COOH + H]+, 658
[M – CF3COOH + Na]+. Found, %: C 59.05; H 7.94;
N 1.86; P 4.12. C35H58NO7P·CF3COOH. Calculated,
%: C 59.28; H 7.88; N 1.87; P 4.14.
3
3
This study was performed under financial support
by the Russian Foundation for Basic Research (project
nos. 12-03-31 138_mol_a, 14-03-31 740mol_a, 13-03-
97073-a, 14-03-00191-a).
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1
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