Choline esterase inhibitors and synthetic oxalic acid receptors based on calix[4]arene derivatives

Article abstract of DOI:10.1007/s11176-005-0213-2

New reversible butyrylcholine esterase inhibitors based on calix[4]arene derivatives were suggested. A series of new distally disubstituted calix[4]arenes were prepared in 60-80% yields. Some of these compounds showed properties of reversible choline este

Full text of DOI:10.1007/s11176-005-0213-2

Russian Journal of General Chemistry, Vol. 75, No. 2, 2005, pp. 278 284. Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 2, 2005,
pp. 305 312.
Original Russian Text Copyright
2005 by Stoikov, Khrustalev, Ibragimova, Stoikova, Evtyugin, Antipin, Konovalov.
Choline Esterase Inhibitors and Synthetic Oxalic Acid Receptors
Based on Calix[4]arene Derivatives
I. I. Stoikov, A. A. Khrustalev, D. Sh. Ibragimova, E. E. Stoikova,
G. A. Evtyugin, I. S. Antipin, and A. I. Konovalov
Kazan State University, Kazan, Tatarstan, Russia
Received June 5, 2003
Abstract New reversible butyrylcholine esterase inhibitors based on calix[4]arene derivatives were sug-
gested. A series of new distally disubstituted calix[4]arenes were prepared in 60 80% yields. Some of these
compounds showed properties of reversible choline esterase effectors, activating it at low concentrations and
inhibiting at high concentrations. The macrocycles prepared were tested in extraction of d,l-tartaric, glycolic,
d,l-mandelic, d,l-glutamic, malonic, oxalic, and succinic acids and of sodium acetate. Oxalic acid is efficiently
transferred through a liquid impregnated membrane under the action of calix[4]arenes with nitrogen-contain-
ing substituents.
Various biochemical processes such as recognition,
reaction, active and selective transport, and reception
[1] are based on intermolecular interactions. Transfor-
mation of the genetic information into such cell func-
tions as growth activation and regulation of enzymes
[1] is based on recognition and selective binding of
the protein surface with biopolymers. Active studies
made in the past decade are aimed at development of
synthetic small molecules whose target is protein
protein interaction [2, 3].
1,3-disubstituted (at the lower rim) p-tert-butylcalix-
[4]arenes containing proton-donor (I), proton-acceptor
(II), and electron-acceptor (III, IV) groups. Dicarbox-
ylic acid I was prepared by hydrolysis of the corre-
sponding ester. Compounds II IV were prepared by
selective alkylation of p-tert-butylcalix[4]arene with
the corresponding halo derivatives in acetonitrile in
the presence of potassium carbonate.
Relatively simple and synthetically accessible mol-
ecules capable to reversibly switch various functions
of proteins are interesting as potential components of
drugs enhancing the specificity of the active compo-
nent and its selective transport in patient’s body [4].
However, the high degree of solvation and large area
of the protein surface complicate the designing of
molecules capable to reversibly alter the protein func-
tion. Calixarenes, being low-toxic and containing
several functionalization centers, show promise for
development of new highly effective drugs.
O
O
O
O
H
H
R
R
R = 4-CH2 C6H4 COOH (I), 4-CH2 C5H4N (II), 4-CH2
C6F5 (III), 4-CH2 C6H4O (4-C6H4NO2) (IV).
We have shown recently that some distally substi-
tuted calix[4]arenes inhibit the hydrolysis of indo-
phenyl acetate with butyrylcholine esterase, which is
due to formation of host guest complexes of calix-
arene with indophenyl acetate and localization of the
resulting supramolecule near the active center of the
enzyme [3].
Calixarenes I IV showed pronounced biological
activity. In particular, they alter the activity of one of
the key enzymes of higher animals, choline esterase,
reversibly enhancing or suppressing its activity toward
a specific substrate, indophenyl acetate.
Calixarenes exert an activating effect when in low
concentrations and an inhibiting effect when in high
concentrations (Table 1). The reversibility of the ef-
fect of calixarenes is confirmed by the independence
To examine the influence of structural factors on
the interaction of calix[4]arenes with a model protein,
butyrylcholine esterase, we prepared a series of new
1070-3632/05/7502-0278 2005 Pleiades Publishing, Inc.

CHOLINE ESTERASE INHIBITORS AND SYNTHETIC OXALIC ACID RECEPTORS
279
OCOCH3 + H2Ocholine esterase
O
N
OH
N
O
indophenol O2
Oxidation products
(brown)
of their effect from the order of adding the reactants
and by the constancy of the reaction rate change at
varied time of contact of the enzyme and calixarene.
The inversion of the biological effect was observed at
Table 1. Analytical characteristics of the determination of
calixarenes I IV by the biochemical effect (0.002 M TRIS
buffer solution, pH 7.6)a
5
a calixarene concentration of 1.9 10 M for II and
Calix-
[4]-
C 105,
5
IV at pH 7.6, 2.3 10 M for IV at pH 4, and 4.9
a
b
r
Mb
5
10 M for II at pH 4 (Fig. 1). The activating and
arene
inhibiting effects of the calixarenes are described by
a common calibrating dependence in the coordinates
enzymatic reaction rate effector concentration.
The only exception is calixarene III, which exerts no
appreciable activating or inhibiting effect at pH 7.6
but behaves as an inhibitor in an acidic medium, in
which D0/DI = (1.005 0.020) + (0.018 0.004)
I
II
0.998 0.030 0.014 0.001 0.9845 0.22 54.60
0.909 0.014 0.046 0.003 0.9860 0.24 10.91
IV 0.790 0.011 0.084 0.003 0.9980 1.19 8.24
a
5
(a, b) Coefficients of the equation D /D = a + bC 10 ,
where D and D are changes in the optical density in a
control run and in the presence of calixarene; C, calixarene
concentration; and r, correlation coefficient.
0
I
0
I
5
10 C. The regular trends revealed allow the effect
b
exerted by calixarenes on choline esterase to be con-
trolled by varying the substituents and pH of the me-
dium. This may be useful in development of cholin-
ergic drugs.
Range of
measurable concentrations.
arene core is sufficiently rigid and allows, by choos-
ing appropriate functional groups, construction of
molecules with the required surface topology, capable
of highly selective recognition of definite substrates.
One of the main approaches to binding of protein
surfaces with synthetic receptors is based on recogni-
tion of carboxy groups on the protein surface [5].
Designing of molecules recognizing carboxylic acids
is difficult, because selective recognition should in-
volve at least three-point binding. In this connection,
it seems promising to use calix[4]arenes. The calix-
We have shown previously that calix[4]arenes con-
taining two distally arranged aromatic substituents at
the lower rim are capable of molecular recognition of
D0/DI
(a)
(b)
D0/DI
1.0
1.4
II
III
IV
0.8
0.6
0.4
0.2
1.2
1.0
0
2
4
6
8
10
105, M
0
1
2
3
4
5
6
C
104, M
C
Fig. 1. Effect of calixarenes (a) I and (b) II IV on the rate of product accumulation in hydrolysis of indophenyl acetate
effected with choline esterase. Photometric detection; (D , D ) optical densities of the solution in the absence and in the
0
I
presence of calixarene, respectively. Measurement time 5 min; (C) calixarene concentration.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 75 No. 2 2005

280
STOIKOV et al.
carboxylic acids [7]. To recognize substrates contain-
ing two carboxy groups, we introduced into the lower
rim of calix[4]arene additional binding centers, amide
groups, capable to interact with both proton-donor and
proton-acceptor fragments of the compounds.
a series of new calix[4]arene derivatives: VI, VII, IX,
and X. By the reaction of diamine V [8] with benzoic
anhydride in benzene, we prepared diamide VI; its
subsequent selective ipso nitration with a mixture of
nitric and acetic acids yielded dinitro derivative VII.
Diamides IX and X were prepared by the reaction of
1
To vary such factors as the distance between the
amide and hydroxy groups of calix[4]arene, sequence
of atom binding in amide groups, lipophilicity, and
acid base properties of phenolic groups, we prepared
VIII with excess amine at 110 C. In the H NMR
spectra of I X, the bridging methylene protons of the
macrocycles give two doublets, suggesting the cone
conformation of the calixarenes [7].
NO2
NO2
HNO3/AcOH
(PhCO)2O
O
O
N
O
O
O
N
O
O
O
N
HPh
CH2Cl2
O
O
O
H
H
O
H
H
H
H
H
H
H
H
N
NH2
H2N
O
O
O
O
VI
VI
VII
RNH2
O
O
O
O
O
O
O
O
H
H
H
H
H
O
O
O
O
H
N
O
N
O
R
R
VIII
IX, X
R = (CH2)7CH3 (IX), CH2Ph (X).
The complexing properties of the compounds pre-
pared were evaluated by the membrane transport of
substrates containing a carboxy group in the acidic
[dicarboxylic acids (tartaric, oxalic, malonic, succin-
ic), -hydroxy acids (glycolic, mandelic)] or ionized
(sodium acetate, glutamic acid) form. The lipophilic
membrane was a solution of calixarene I IV, VI, VII,
or IX in o-nitrophenyl octyl ether XI, impregnated
into pores of a Teflon matrix [7]. Compound X is
poorly soluble, and, therefore, it was not used as a
membrane-transfer agent.
The initial flows (j) and enhancement factors of the
transfer ( = j/j0) of the substrates through a liquid
impregnated membrane are given in Table 2. In the
head row of the table, we also give the pKa values [9]
and the log octanol water partition coefficients (logP)
[10] characterizing the hydrophilicity of the com-
pounds.
Addition of calix[4]arenes I IV, VI, VII, and IX
to the membrane phase affects the rate of the substrate
transfer differently. For the majority of the macro-
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CHOLINE ESTERASE INHIBITORS AND SYNTHETIC OXALIC ACID RECEPTORS
281
2
Table 2. Initial flows [ja ,b mol h 1 m ] and enhancement factors of the transfer ( = j/j0, in parentheses) of a series
of organic substrates through a liquid impregnated membrane (25 C)
d,l-Tartaric
Glycolic
acid:
d,l-Mandelic d,l-Glutamic
acid: acid:
Oxalic
acid:
Malonic
acid:
Amber
acid:
Succinic
acetate:
logP 4.24
acid:
logP 1.96, logP 1.02, logP 0.64,
pKa 2.89
logP 4.6, logP 1.88, logP 0.49, logP 0.47,
pKa 3.83
pKa 3.37
pKa 4.33
pKa 1.25
pKa 1.38
pKa 4.21
I
(1.6 0.1)
(3.4 0.3)
(5.4 0.5)
(1.0 0.1)
(1.8 0.1)
(1.0 0.1)
(4.6 0.4) (4.6 0.4)
9
9
9
9
9
9
9
9
10
(1.0)
10
(1.0)
10
(1.0)
10
(1.0)
10
(1.0)
10
(1.0)
10
(1.0)
10
(1.0)
II
(1.7 0.1)
(18.1 1.5) (2.01 0.1)
(1.0 0.1)
(5.4 0.3)
(3.55 0.3) (52.3 3.5) (4.6 0.4)
9
9
6
9
7
8
9
9
10
(1.0)
10
10
10
(1.0)
10
(299.0)
10
(3.6)
(1.0 0.1)
10
(1.0)
(1.0 0.1)
10
(1.0)
(8.4 0.5)
10
(8.4)
(4.1 0.4)
10
(4.0)
(1.0 0.1)
10
(1.0)
(1.0 0.1)
10
(11.4)
(4.6 0.4) (4.6 0.4)
10
(1.0)
(3.5)
(3.7)
III (1.6 0.1)
(3.4 0.3)
(5.4 0.5)
(1.0 0.1)
(1.8 0.1)
9
9
7
9
7
8
9
9
10
10
10
10
10
10
(1.0)
(5.9 0.5) (4.6 0.4)
10
(1.0)
(1.0)
(1.0)
(1.0)
(1.0)
(1.0)
IV (1.6 0.1)
(3.4 0.3)
(5.4 0.5)
(1.0 0.1)
(6.8 0.5)
9
9
7
9
7
8
9
9
10
10
10
10
10
10
(1.3)
(15.6 1.2) (4.6 0.4)
10
(1.0)
(1.0)
(1.0)
(1.0)
(3.8)
(1.0)
VI (1.1 0.09) (9.2 0.8)
(12.3 1.2)
(1.0 0.1)
(8.8 0.5)
8
9
7
9
8
8
9
9
10
10
10
10
10
10
(3.4)
(4.6 0.4) (4.6 0.4)
10
(6.9)
(2.7)
(2.3)
(1.0)
(48.9)
(1.0)
VII (2.2 0.2)
(7.5 0.6)
(9.2 0.9)
(25.4 1.8) (2.7 0.2)
9
9
7
9
8
8
9
9
10
10
10
10
10
10
(1.0)
(5.0 0.4) (48.3 3.3)
10
(1.4)
(2.2)
(1.7)
(25.0)
(15.0)
(1.0)
IX (1.9 0.2)
(14.1 1.1) (19.3 1.5)
(5.8 0.4)
(1.8 0.1)
9
9
7
9
9
8
9
9
10
10
10
10
10
10
(1.1)
(4.6 0.4) (4.6 0.3)
10
(1.2)
(4.1)
(3.6)
(4.5)
(1.0)
(10.5)
XIc (1.6 0.1)
(3.4 0.3)
(5.4 0.3)
(1.0 0.1)
(1.8 0.1)
9
9
7
9
9
8
9
9
10
10
10
10
10
10
10
10
a
2
b
c
Membrane area S 9.616 cm .
p 95%.
Without transfer agent (j ).
0
cycles, j and increase with an increase in pKa (ex-
cept data for oxalic acid). This trend is apparently
associated with the acid base interaction of the acid
with the receptor. It should be noted that there is no
correlation between the acid lipophilicity (logP) and
enhancement factor of substrate transfer. With the
most lipophilic substrate, mandelic acid, the enhance-
ment factors are insignificant.
acid flow by a factor of 48.9. The enhancement factors
of the transfer of its nearest homologs, malonic and
succinic acids, are as low as 8.4 and 3.4, respectively.
The selectivity of VI toward oxalic acid is apparently
due to formation of a complex in which both carboxy
groups of oxalic acid interact with two amide frag-
ments of the transfer agent. With an increase in the
acidity of phenolic hydroxyls (compound VII), the
transport selectivity changes: Oxalic acid is transferred
with 15, and glutamic acid, with 25. Diamide IX
with the shortest spacer and different orientation of
the amide fragments selectively transfers sodium ace-
tate through a lipophilic membrane ( 10).
Table 2 shows that calix[4]arene II with pyridine
fragments is the most effective and selective transfer
agent. It transfers oxalic acid (the strongest acid in the
examined series) with an enhancement factor of 299.0,
whereas with succinic acid the enhancement factor is
only 11.4. The results of the membrane extraction
reveal a significant influence of not only acid base
interaction (oxalic acid, being the strongest, is trans-
ferred better), but also geometric matching of the
transfer agent and substrate molecules.
Macrocycles I and III containing acceptor substitu-
ents at the lower rim of the calixarene form another
group of transfer agents. Addition of these calixarenes
to the membrane phase does not affect the rate of
transfer of any of the substrates studied. Apparently,
interaction of substrates with only the hydroxy groups
at the lower rim of the calixarene is insufficient for
Macrocycle VI appeared to be the next after II in
the efficiency and selectivity; it enhances the oxalic
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282
STOIKOV et al.
binding of carboxylic acids and their extraction into
the membrane phase [7]. In the case of calix[4]arenes
disubstituted at the lower rim and containing aromatic
groups in lateral fragments, the OH hydrogen bond-
ing contributes to the acid transfer agent complexa-
tion [7]. Apparently, the strength of such a bond will
decrease on introducing electron-withdrawing groups
into aromatic substituents of calix[4]arene. We found
that addition of 4-(4 -nitrophenyloxy)benzyl derivative
IV into the membrane phase slightly (by a factor of
1.3 3.3) enhanced the transport of the examined sub-
strates, compared to the blank experiment. Such a
behavior suggests formation of a transfer agent sub-
strate complex whose energy is insufficient to com-
pensate the energy consumption for the desolvation of
the strongly hydrophilic substrates in water and their
transfer to the lipophilic phase of the membrane.
The membrane extraction of substrates with calix-
arenes was studied following the procedure from [7].
The electrical conductivity of solutions was measured
with a WTW inoLab-Cond Level-1 conductometer.
The following chemicals (all chemically pure grade)
were used: d,l-mandelic, glycolic, d,l-tartaric, d,l-glu-
tamic, oxalic, malonic, and succinic acids and sodium
acetate. The rate of substrate transport across liquid
membranes was measured in a temperature-controlled
vertical glass diffusion cell with a mobile cylinder.
A hydrophobic matrix (Millipole Type-FA porous
Teflon filters, thickness 1 m, pore size 100 nm, 85%
porosity, reinforced with polycaprolactam gauze) was
impregnated with a liquid membrane. The substance
concentrations were determined from the electrical
conductivities of the solutions. The volume ratio of
the feeding and receiving phases was 5 : 1, which pro-
vided the same level of solutions to eliminate osmotic
transfer. The mass transfer experiments were per-
formed under standard conditions (25 C). The initial
substrate solutions were prepared by dissolving an ac-
curately weighed substrate portion in double-distilled
water just before the measurements; the solutions
were used within a day. The liquid membrane was a
solution of calix[4]arene VI X in an organic diluent
or a straight diluent (o-nitrophenyl octyl ether XI).
EXPERIMENTAL
1
The H NMR spectra were recorded on a Varian
XL-300 spectrometer (300 MHz). The chemical shifts
were determined relative to the residual proton signals
of the solvent (CDCl3). The electron impact mass
spectra with determination of the exact masses of
molecular and fragment ions were taken on an MKh-
1310 mass spectrometer (60 eV, 200 450 C).
5,11,17,23-Tetra-tert-butyl-25,27-dihydroxy-
26,28-bis[4 -(carboxy)benzyloxy]calix[4]arene I. A
mixture of 1.00 g of 5,11,17,23-tetra-tert-butyl-25,27-
dihydroxy-26,28-bis[4 -(carboxyethyl)benzyloxy]ca-
lix[4]arene [7], 10 ml of 10% aqueous NaOH, and
10 ml of dimethyl sulfoxide in 100 ml of ethanol was
refluxed for 36 h until the starting compound fully
dissolved. Then the solvent was removed in a vacuum,
30 ml of water was added to the residue, concentrated
HCl was added to pH 1, and the mixture was stirred
for 30 min. The precipitate was filtered off and
washed on a glass frit with water to neutral reaction
of the filtrate. The colorless crystalline precipitate was
recrystallized from ethanol. Yield 0.90 g (71%), mp
The inhibiting effect of calixarenes on native
choline esterase was studied photometrically with an
AKI-Ts-01 colorimetric analyzer equipped with a
530-nm color filter [3]. Butyrylcholine esterase from
horse blood serum (EC 3.1.1.8, class 4, specific activ-
1
ity 16 units mg ) was purchased from the Biomed
Research and Production Association (Perm, Russia);
indophenyl acetate, from Sigma (concentration in the
1
measurement cell 0.03472 mg ml ); and TRIS buffer
solution (analytically pure grade, 0.002 M), from
Reakhim (Russia). Calixarene solutions were prepared
by dissolving a weighed portion of the substance in
1
acetone to obtain a 1 mg ml solution and diluting
1
with the buffer solution to the required concentration.
The rate of the choline esterase reaction was deter-
mined from the amount of the product, indophenol,
formed by enzymatic hydrolysis of indophenyl ace-
tate. The reaction was performed in a cell of a stand-
ard kit for immunochemical studies.
168 169 C. H NMR spectrum (CDCl3), , ppm (J,
Hz): 1.03 s [18H, C(CH3)3], 1.31 s [18H, C(CH3)3],
2
3.42 d (4H, ArCH2eAr, JHH 12.6), 4.39 d (4H,
2
ArCH2aAr, JHH 12.6), 5.16 s (4H, OCH2Ar), 6.93 s
(4H, ArH), 7.10 s (4H, ArH), 7.79 s (2H, OH), 7.91 d
3
(4H, CH2C6H4CO2H, JHH 8.4), 7.97 d (4H, CH2
3
C6H4CO2H, JHH 8.4). Found, %: C 78.19; H 7.93.
The reaction rate was determined from the slope of
the initial linear portion of the kinetic curve in the
solution optical density time coordinates. The activat-
ing and inhibiting effects were estimated from the rel-
ative change in the reaction rate in the presence of
calixarenes, which were added directly to the meas-
urement cell containing the enzyme solution before or
simultaneously with adding the substrate.
C60H68O8. Calculated, %: C 78.57; H 7.47. Found m/z
916.4919 [M]+. Calculated M 916.4914.
5,11,17,23-Tetra-tert-butyl-25,27-dihydroxy-
26,28-bis(4 -pyridylmethoxy)calix[4]arene II.
A
mixture of 1.00 g of 5,11,17,23-tetra-tert-butyl-25,26,
27,28-tetrahydroxycalix[4]arene, 3.14 g of anhydrous
potassium carbonate, and 1.15 g of anhydrous sodium
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CHOLINE ESTERASE INHIBITORS AND SYNTHETIC OXALIC ACID RECEPTORS
283
iodide in 150 ml of acetonitrile was refluxed with
stirring under argon for 30 min. Then a solution of
0.54 g of 4-chloromethylpyridine hydrochloride in
30 ml of anhydrous methanol was added over a period
of 2 h, after which the mixture was refluxed with
stirring for an additional 20 h. Then the mixture was
cooled to 50 C and filtered on a glass frit; the preci-
pitate was washed with acetonitrile (2 30 ml), and
the solvent from the combined filtrates was removed.
The dry residue was dispersed in 150 ml of water for
30 min, filtered off on a glass frit, and washed with
water until the filtrate became colorless, after which
it was recrystallized from a mixture of 50 ml of di-
ethyl ether and 15 ml of acetonitrile. The colorless
needle-like precipitate was dried in a vacuum
(0.01 mm Hg) at 100 C for 12 h. Yield 0.79 g (62%),
C(CH3)3], 1.30 s [18H, C(CH3)3], 3.31 d (4H,
2
2
ArCH2eAr, JHH 13.3), 4.28 d (4H, ArCH2aAr, JHH
13.3), 5.06 s (4H, OCH2Ar), 6.80 s (4H, ArH), 7.08 s
(4H, ArH), 7.15 s (2H, OH), 6.97 d (4H, CH2C6H4O,
3
3JHH 8.9), 7.03 d (4H, CH2C6H4O, JHH 8.9), 7.71 d
3
(4H, OC6H4NO2, JHH 8.8), 8.16 d (4H, OC6H4NO2,
3JHH 8.8). Found, %: C 75.98; H 6.89; N 2.61.
C70H74N2O10. Calculated, %: C 76.20; H 6.76; N 2.54.
Found m/z 1102.5340 [M]+. Calculated M 1102.5344.
5,11,17,23-Tetra-tert-butyl-25,27-bis[2 -(benzoyl-
amino)ethoxy]-26,28-dihydroxycalix[4]arene VI. A
mixture of 4.00 g of 5,11,17,23-tetra-tert-butyl-25,27-
bis(2 -aminoethoxy)-26,28-dihydroxycalix[4]arene
V
[8], 2.61 g of benzoic anhydride, and 30 ml of
benzene was refluxed for 2 h. Then the solvent was
removed in a vacuum, the dry residue was dispersed
for 30 min in 150 ml of a saturated solution of sodium
carbonate, the suspension was filtered on a glass frit,
and the precipitate was washed with water (3 50 ml)
and dried over P2O5. The resulting product was dis-
solved in a minimal amount of dichloromethane and
precipitated with hexane. The colorless precipitate was
dried in a vacuum (0.01 mm Hg) at 100 C for 12 h.
1
mp 108 109 C. H NMR spectrum (CDCl3), , ppm
(J, Hz): 0.93 s [18H, C(CH32)3], 1.30 s [18H, C(CH3)3],
3.33 d (4H, ArCH2eAr, JHH 13.4), 4.25 d (4H,
2
ArCH2aAr, JHH 13.4), 5.07 s (4H, OCH2Pyr), 6.79 s
(4H, ArH), 6.97 s (2H, OH), 7.07 s (4H, ArH), 7.64 d
3
(4H, CH2C5H4N, JHH 6.1), 8.63 d (4H, CH2C5H4N,
3JHH 6.1). Found, %: C 79.37; H 8.15; N 3.41.
C56H66N2O4. Calculated, %: C 80.93; H 8.00; N 3.37.
Found m/z 830.5028 [M]+. Calculated M 830.5023.
1
Yield 2.70 g (59%), mp 135 136 C. H NMR spec-
trum (CDCl3), , ppm (J, Hz): 1.12 s [18H, C(CH3)3],
2
1.23 s [18H, C(CH3)3], 3.39 d (4H, ArCH2eAr, JHH
5,11,17,23-Tetra-tert-butyl-25,27-dihydroxy-
26,28-disubstituted calix[4]arenes III and IV (gene-
ral procedure). A mixture of 1.54 mmol of 5,11,17,23-
tetra-tert-butyl-25,26,27,28-tetrahydroxycalix[4]arene,
3.24 mmol of appropriate alkyl bromide, and
13.90 mmol of anhydrous potassium carbonate in
30 ml of acetonitrile was refluxed with stirring for
12 h. Then the solvent was removed in a vacuum, and
the dry residue was treated with 10 ml of 5 M HCl
and 50 ml of CHCl3. The organic phase was sep-
arated, washed with distilled water (3 30 ml), and
3
3
14.1), 3.62 d.t (4H, CH2N, JHH 4.5, JHH 4.9), 4.03 t
3
2
(4H, OCH2, JHH 4.5), 4.18 d (4H, ArCH2aAr, JHH
14.1), 7.02 s (4H, ArH), 7.07 s (4H, ArH), 7.31 d.d
3
3
(4H, ArH, JHH 7.4, JHH 7.1), 7.43 t.t (2H, ArH,
3JHH 7.4, JHH 1.3), 7.95 d.d (4H, ArH, JHH 7.1,
4JHH 1.3), 8.21 t (2H, NH, 3JHH 4.9), 8.39 s (2H, OH).
Found, %: C 78.91; H 7.98; N 2.95. C62H74N2O6.
Calculated, %: C 78.95; H 7.91; N 2.97. Found m/z
942.5551 [M]+. Calculated M 942.5547.
4
3
5,17-Di-tert-butyl-11,23-dinitro-25,27-bis-[2 -
(benzoylamino)ethoxy]-26,28-dihydroxycalix[4]-
arene VII. A mixture of 0.47 g of 5,11,17,23-tetra-
tert-butyl-25,27-bis[2 -(benzoylamino)ethoxy]-26,28-
dihydroxycalix[4]arene VI, 50 ml of dichloromethane,
2.9 ml of glacial acetic acid, and 5.6 ml of 65% nitric
acid was stirred for 30 min at room temperature, after
which it was poured into 50 ml of water. The organic
layer was washed with two portions of water and
dried over magnesium sulfate. The solvent was re-
moved in a vacuum. The residue was recrystallized
dried over 4
molecular sieves. The solvent was
removed on a rotary evaporator, and the residue was
recrystallized from chloroform methanol.
5,11,17,23-Tetra-tert-butyl-25,27-dihydroxy-
26,28-bis(pentafluorophenylmethoxy)calix[4]arene
1
III. Yield 1.33 g (86%), mp 222 C. H NMR spec-
trum (CDCl3), , ppm (J, Hz): 0.94 s [18H, C(CH3)3],
2
1.30 s [18H, C(CH3)3], 3.28 d (4H, ArCH2eAr, JHH
2
13.1), 4.22 d (4H, ArCH2aAr, JHH 13.1), 5.09 s (4H,
OCH2), 6.39 s (2H, OH), 6.75 s (4H, ArH), 7.06 s
(4H, ArH). Found, %: C 68.73; H 5.85. C58H58F10O4.
Calculated, %: C 69.04; H 5.79. Found m/z 1008.4179
[M]+. Calculated M 1008.4175.
from a dichloromethane hexane mixture. Yield 0.11 g
1
(28%), mp 135 C. H NMR spectrum (CDCl3),
,
ppm (J, Hz): 1.01 s [18H, C(CH3)3], 3.49 d (4H,
2
3
ArCH2eAr, JHH 13.4), 3.82 d.t (4H, CH2N, JHH 4.8,
3
5,11,17,23-Tetra-tert-butyl-25,27-dihydroxy-
3JHH 5.5), 4.12 t (4H, OCH2, JHH 4.8), 4.18 d (4H,
2
26,28-bis[4 -(4 -nitrophenyloxy)benzyloxy]calix[4]-
ArCH2aAr, JHH 13.4), 6.90 s (4H, ArH), 7.30 m (4H,
1
3
arene IV. Yield 1.60 g (94%), mp 128 C. H NMR
ArH), 7.44 m (2H, ArH), 7.69 t (2H, NH, JHH 5.5),
7.86 d (4H, ArH, JHH 7.5), 8.04 s (4H, ArH), 8.94 s
3
spectrum (CDCl3), , ppm (J, Hz): 0.95 s [18H,
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 75 No. 2 2005

284
STOIKOV et al.
(2H, OH). Found, %: C 70.39; H 6.15; N 6.12.
C54H56N4O10. Calculated, %: C 70.42; H 6.13; N 6.08.
Found m/z 920.4001 [M]+. Calculated M 920.3996.
N 2.97. Found m/z 942.5551 [M]+. Calculated M
942.5547.
ACKNOWLEDGMENTS
5,11,17,23-Tetra-tert-butyl-25,27-bis(N-octylcar-
bamoylmethoxy)-26,28-dihydroxycalix[4]arene IX.
A mixture of 1.58 g of 5,11,17,23-tetra-tert-butyl-
25,27-dihydroxy-26,28-bis(ethoxycarbonylmethoxy)-
calix[4]arene VIII [11], 9.5 ml of octylamine, and
0.16 g of ammonium chloride was stirred at the boil-
ing point of octylamine for 2.5 h. Then excess octyl-
amine was distilled off, and the residue was washed
with water (2 10 ml) and 1 M HCl (3 10 ml). The
mixture was separated by flash chromatography on
30 g of silica gel L 50/40 (first eluent 10 ml of chloro-
form isopropanol, 2 : 1; second, 10 ml of chloroform
isopropanol, 1 : 1; and third, 10 ml of chloroform
isopropanol, 1 : 2). The solvent was removed in a
vacuum. The reaction product, colorless glassy mass,
was dried in a vacuum (0.001 mm Hg) at 100 C for
12 h. Yield 1.10 g (60%). 1H NMR spectrum (CDCl3),
The study was financially supported by the RF
Ministry of Education (project no. PD 02-1.3-95),
Basic Research and Higher Education (BRHE) pro-
gram (grant REC-007), and Russian Foundation for
Basic Research (project nos. 02-03-32888, 02-03-
32934, and 03-03-96185).
REFERENCES
1. Elliott, W.H. and Elliott, D.C., Biochemistry and
Molecular Biology, Oxford Univ. Press, 1997; 2001,
2nd ed. Translated under the title Biokhimiya i mole-
kulyarnaya biologiya, Moscow: Nauka/Interperiodica,
2002, p. 444.
2. Park, H.S., Lin, Q., and Hamilton, A.D., J. Am. Chem.
Soc., 1999, vol. 121, no. 1, p. 8.
3
, ppm (J, Hz): 0.84 t [6H, CH3(CH2)7, JHH 6.9],
1.05 s [18H, C(CH3)3], 1.27 s [18H, C(CH3)3], 1.36
3. Stoikova, E.E., Evtugyn, G.A., Beljakova, S.V.,
Khrustalev, A.A., Stoikov, I.I., Antipin, I.S., Budni-
kov, H.C., and Konovalov, A.I., J. Inclus. Phenom.,
2001, vol. 39, no. 3/4, p. 339.
1.10 m [24H, CH2(CH2)6CH3], 3.38 d.t [4H,
3
3
NHCH2(CH2)6CH3, JHH 5.2, JHH 6.7], 3.43 d (4H,
2
2
ArCH2eAr, JHH 13.2), 4.12 d (4H, ArCH2aAr, JHH
13.2), 4.56 s [4H, OCH2C(O)NH], 6.94 s (4H, ArH),
7.08 s (4H, ArH), 7.86 s (2H, OH), 8.84 t (2H, NH,
3JHH 5.2). Found, %: C 77.37; H 9.85; N 2.51.
C64H94N2O6. Calculated, %: C 77.80; H 9.59; N 2.84.
Found m/z 986.7121 [M]+. Calculated M 986.7112.
4. Peczuh, M.W., Hamilton, A.D., Sanchez-Quesada, J.,
Mendoza, J. de, Haack, T., and Giralt, E., J. Am.
Chem. Soc., 1997, vol. 119, no. 39, p. 9327.
5. Mandolini, L. and Ungaro, R., Calixarenes in Action,
Imperial College Press, 2000, p. 271.
5,11,17,23-Tetra-tert-butyl-25,27-bis(N-benzyl-
carbamoylmethoxy)-26,28-dihydroxycalix[4]arene
VI. A mixture of 0.5 g of 5,11,17,23-tetra-tert-butyl-
25,27-dihydroxy-26,28-bis(ethoxycarbonylmethoxy)-
calix[4]arene VIII [11], 3 ml of benzylamine, and
0.05 g of ammonium chloride was stirred at the boil-
ing point of benzylamine for 1 h. Then the mixture
was poured into 10 ml of water, and the resulting
gelatinous mass was washed on a glass frit with 1 M
HCl (5 10 ml). The white precipitate was recrystal-
6. Asfani, Z., Bohmer, V., Harrowfield, J., Vicens, J.,
and Saadioui, M., Calixarenes 2001, Dordrecht:
Kluwer Academic, 2001, p. 683.
7. Antipin, I.S., Stoikov, I.I., Khrustalev, A.A., and Ko-
novalov, A.I., Izv. Ross. Akad. Nauk, Ser. Khim., 2001,
no. 11, p. 2038.
8. Wolf, N.J., Georgiev, E.M., Yordanov, A.T., Whit-
tlesey, B.R., Koch, H.F., and Roundhill, D.M., Poly-
hedron, 1999, vol. 18, p. 885.
9. Dawson, R., Elliott, D., Elliott, W., and Jones, K.,
Data for Biochemical Research, Oxford: Clarendon,
1986, p. 544.
lized from dichloromethane hexane. Yield 0.20 g
1
(38%), mp 266 C. H NMR spectrum (CDCl3),
,
ppm (J, Hz): 0.97 s [18H, C(CH3)3], 1.27 s [18H,
2
10. Stoikov, I.I., Repeikov, S.A., Antipin, I.S., and Ko-
novalov, A.I., Heteroatom Chem., 2000, no. 11,
p. 518.
C(CH3)3], 3.28 d (4H, ArCH2eAr, JHH 13.3), 3.79 d
2
(4H, ArCH2aAr, JHH 13.3), 4.35 s [4H, OCH2
3
N(O)NH], 4.52 d (4H, NHCH2Ph, JHH 4.3), 6.80 s
(4H, ArH), 6.99 s (2H, OH), 7.00 s (4H, ArH), 8.91 t
(2H, NH, JHH 4.3). Found, %: C 78.37; H 8.05; N
3.01. C62H74N2O6. Calculated, %: C 78.95; H 7.91;
11. Collins, E.M., McKervey, M.A., Madigan, E., Mo-
ran, M.B., Owens, M., Ferguson, G., and Harris, S.J.,
J. Chem. Soc., Perkin Trans. 1, 1991, no. 3, p. 3137.
3
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 75 No. 2 2005