Effect of the structure of phase-transfer catalyst on the rate of alkaline hydrolysis of N-benzyloxycarbonylglycine 4-nitrophenyl ester in the system chloroform-borate buffer

Article abstract of DOI:10.1023/A:1016334125761

Onium salts QZ (Z = Cl, Br) having a lipophilic (Q = R₃NR′ , where R′ = C₁₆H₃₃) or readily extractable (into organic phase) cation (Q = Ph₄P) exhibit a high catalytic activity in phase-transfer alkaline hydrolysis of N-benzyloxycarbonylglycine 4-nitrophenyl ester in the two-phase system chloroform-borate buffer (pH 10). No catalytic effect is observed in the presence of hydrophilic ammonium salts [Et₄NCl, Et₃PhCH₂NCl, Me₂(NH ₂)N⁺CH₂CH₂N⁺(NH ₂)Me₂·2Br^-] and those insoluble in organic solvents [(Me)₃N⁺NH(CH₂) ₂COO^-·2H₂O, Me₂(NH ₂)N⁺CH₂CO^-, Me₂(NH ₂)N⁺(CH₂)₃SO₃ ^-]. These data suggest extraction mechanism of the process. The activity of lipophilic cation Q is determined mainly by two factors: its extractibility, on the one hand, and the ability to form micelles, on the other.

Full text of DOI:10.1023/A:1016334125761

Russian Journal of Organic Chemistry, Vol. 38, No. 3, 2002, pp. 378 384. Translated from Zhurnal Organicheskoi Khimii, Vol. 38, No. 3, 2002,
pp. 400 406.
Original Russian Text Copyright
2002 by Baranova, Kosmynin, Savelova, Shendrik, Korotkikh, Raenko, Popov.
Effect of the Structure of Phase-Transfer Catalyst
on the Rate of Alkaline Hydrolysis
of N-Benzyloxycarbonylglycine 4-Nitrophenyl Ester
in the System Chloroform Borate Buffer
1
1
2
1
O. V. Baranova , V. V. Kosmynin , V. A. Savelova , A. N. Shendrik ,
2
2
2
N. I. Korotkikh , G. F. Raenko , and A. F. Popov
1
Donetsk National University, ul. Universitetskaya 24, Donetsk, 83055 Ukraine
2
Litvinenko Institute of Physical Organic and Coal Chemistry, National Academy of Sciences of Ukraine,
ul. R. Luxemburg 70, Donetsk, 83114 Ukraine
Received August 8, 2001
Abstract Onium salts QZ (Z = Cl, Br) having a lipophilic (Q = R3NR , where R = C16H33) or readily
extractable (into organic phase) cation (Q = Ph4P) exhibit a high catalytic activity in phase-transfer alkaline
hydrolysis of N-benzyloxycarbonylglycine 4-nitrophenyl ester in the two-phase system chloroform borate
buffer (pH 10). No catalytic effect is observed in the presence of hydrophilic ammonium salts [Et4NCl,
+
+
Et3PhCH2NCl, Me2(NH2)NCH2CH2N(NH2)Me2 2Br ] and those insoluble in organic solvents
+
+
+
[(Me)3NNH(CH2)2COO 2H2O, Me2(NH2)NCH2CO , Me2(NH2)N(CH2)3SO3]. These data suggest extraction
mechanism of the process. The activity of lipophilic cation Q is determined mainly by two factors: its
extractibility, on the one hand, and the ability to form micelles, on the other.
Hydroxide ion participates in many phase-transfer
processes as a nucleophile or a base. However, studies
on the kinetics of phase-transfer reactions involving
hydroxide ion are very few in number [1 3]. As noted
in [2], the problem of hydroxide ion transfer into
organic phase is very important, but it has not been
solved unequivocally. The main reason is that it is
difficult to determine experimentally the concentration
of hydroxide ion in weakly polar organic solvents.
Therefore, interphase mechanism with participation of
OH ion is generally considered [3].
We previously studied kinetic relations holding in
alkaline hydrolysis of N-benzyloxycarbonylglycine
4-nitrophenyl ester in the systems 1-butanol borate
buffer (pH 8.3, 10) [4] and chloroform borate buffer
(pH 10, 11) [5, 6] in the presence of some tetra-
substituted ammonium and phosphonium salts. The
results of these studies were interpreted in favor of
Scheme 1.
I, Z = Cl, Br.
1070-4280/02/3803-0378$27.00 2002 MAIK Nauka/Interperiodica

EFFECT OF THE STRUCTURE OF PHASE-TRANSFER CATALYST
379
the extraction mechanism of catalysis, where the rate-
determining stage is chemical reaction in the organic
phase. Tetraphenylphosphonium salts I with various
anions, tetrasubstituted ammonium bromide II, and
benzimidazolium bromide III were used as phase-
transfer catalysts. These salts are readily extractable
into organic phase.
In order to obtain more reliable proofs for the
extraction mechanism of the reaction under study, we
thought it reasonable to extend the series of lipophilic
catalysts and also to examine the process in the pres-
ence of hydrophilic salts. For this purpose, we used
salts IV XII as phase-transfer catalysts (Scheme 1).
The first three of these, salts IV VI, are lipophilic;
compounds VII IX are hydrophilic; and zwitterionic
compounds X XII are interesting as potential phase-
transfer catalysts.
inorganic anions from aqueous to organic phase.
Therefore, the rate of such reactions strongly depends
on the lipophilicity of onium cation [7]. On the other
hand, hydrophilic phase-transfer catalysts having short
hydrocarbon radicals exhibit the highest catalytic
activity in reactions following the interphase mecha-
nism. In this case, the decisive factor is accessibility
of the positively charged center in onium cation for
association with organic anion, which increases as
the alkyl chain shortens [8]. Taking into account that
dipolar salts are as a rule almost insoluble in organic
solvents, phase-transfer reactions catalyzed by such
salts are believed [9] to follow the interphase mecha-
nism. Then, a fairly high catalytic activity of salts
I VI and the absence of catalytic activity of hydro-
philic (VII IX) and dipolar salts (X XII) can be
regarded as an indirect evidence in favor of the extrac-
tion mechanism.
The hydrolysis of N-benzyloxycarbonylglycine
4-nitrophenyl ester in a two-phase system follows the
stoichiometric equation given in Scheme 2 [4, 5].
In order to estimate the catalytic activity of salts
IV VI in the hydrolysis of N-benzyloxycarbonyl-
glycine 4-nitrophenyl ester we examined its kinetics
3
at a constant substrate concentration (5 10 M) on
Scheme 2.
variation of the concentration of catalyst. Figure 1
shows semilog kinetic curves in the first-order reac-
tion coordinates. The plots are linear up to a 80%
conversion of the substrate, i.e., the process can
formally be regarded as pseudounimolecular. These
The kinetics of the reaction were monitored by
accumulation of 4-nitrophenoxide ion (4-NO2C6H4O )
in the two-phase system chloroform borate buffer
(volume ratio 1:1, pH 10, temperature 25 C). The
given concentrations of the ester and catalyst (ccat)
were calculated on the overall volume of the two-
phase system. The indices org, aq, and 2-ph
denote the organic phase, aqueous phase, and two-
phase system as a whole, respectively.
Our preliminary experiments showed that hydro-
philic salts VII IX and dipolar salts X XII having no
long-chain lipophilic groups on the nitrogen do not
exhibit catalytic activity. In the presence of these salts
we failed to detect by UV spectroscopy accumulation
of the hydrolysis product (4-nitrophenoxide ion) in the
two-phase system over a period exceeding the half-
conversion period in the presence of salts I VI by
a factor of 10 to 50. Lipophilic salts IV VI ensured
a sufficiently high rate of the hydrolysis in the two-
phase system.
Fig. 1. Plots of ln[a/(a x)] versus time ( ) for alkaline
hydrolysis of N-benzyloxycarbonylglycine 4-nitrophenyl
ester in the two-phase system chloroform borate buffer,
pH 10 (1:1), in the presence of phase-transfer catalysts
The observed differences in the catalytic activity
of salts I XII may be interpreted as follows. The
main function of a phase-transfer catalyst in SN2 reac-
tions following the extraction mechanism is to transfer
3
3
(1) V, ccat = 3 10 M; (2) IV, ccat = 8 10 M; and
2
(3) VI, ccat = 5 10 M. Temperature 25 C.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 38 No. 3 2002

380
BARANOVA et al.
Pseudofirst-order rate constants (k2-ph) and (k2-ph ) determined by approximation of the experimental kinetic data using
Eqs. (1) and (1 ), respectively, for phase-transfer catalysts IV VI on variation of their concentration (ccat); 25 C
1
1
Catalyst
ccat 103, M
k2-ph 104, s
k2-ph 104, s
b
Na
IV
1
2
5
8
10
20
1.5 0.1
2.5 0.1
4.6 0.3
11.2 0.3
14.0 0.3
15.0 0.6
1.60 0.05
3.0 0.1
0.25 0.06
0.30 0.02
0.5 0.1
0.1 0.1
0.12 0.04
0.12 0.02
31
34
27
36
41
25
10.9 0.4
12.7 0.5
17.5 0.7
V
1
3
5
8
9
9.5
10
12.5
15
20
30
0.31 0.02
0.61 0.06
0.79 0.07
1.1 0.1
1.62 0.01
1.8 0.1
3.2 0.7
3.9 0.9
2.5 0.4
2.4 0.2
0.22 0.01
0.65 0.02
0.71 0.03
1.21 0.03
1.45 0.07
0.11 0.03
0.16 0.05
0.22 0.08
0.27 0.03
0.11 0.01
0.14 0.03
0.28 0.06
0.32 0.07
0.19 0.06
0.18 0.01
0.30 0.01
26
28
22
32
25
33
64
30
32
26
29
2.7 0.1
2.48 0.05
VI
3
5
10
30
50
0.29 0.02
0.5 0.1
1.09 0.04
1.65 0.02
2.4 0.2
0.38 0.07
0.29 0.02
0.15 0.01
0.5 0.1
26
45
41
26
36
0.64 0.02
1.03 0.03
2.50 0.05
0.20 0.03
a
N is the number of points.
plots do not pass through the origin but cut statistic-
ally reliable intercepts on the y axis. The correspond-
ing values (b) are given in table. They were obtained
by linear approximation of the kinetic results using
the following equation:
All salts IV VI in the initial form contain the same
counterion Cl , i.e., in all cases competing transfer of
Cl (Z) and 4-NO2ArO (X) ions occurs through the
phase boundary by the cation. Taking into account
that salts IV VI have different cations, we cannot
sel
X/Z
assert with certainty that the K
values for all
catalysts change in parallel, depending on the concen-
tration of 4-NO2ArO . However, such a possibility
cannot be ruled out for the following reasons. The
lengths b (see table) almost do not depend on the
catalyst concentration and its structure, as follows
from the results of statistical treatment of data arrays
obtained for particular catalyst. For this purpose, the
experimental data for each catalyst at various concen-
trations were approximated using Eq. (1 ), which is
analogous to Eq. (1):
ln[a/(a
x)] = k2-ph + b.
(1)
1
Here, k2-ph (s ) is the apparent pseudofirst-order
rate constant; a is the initial substrate concentration
(M); and x is the product concentration (M) by
a moment . Analogous relations were observed by us
previosuly for the same reaction in the presence of
salts I (Z = Cl) and II [5]. They were explained [5]
in terms of competing anion (Z ) exchange between
the initial form of phase-transfer catalyst and 4-nitro-
phenoxide ion (X ) fromed during the process.
ln[a/(a
x)] = k2-ph
+ b .
(1 )
Another possible reason is variation of the ion
exchange selectivity constant K , depending on the
sel
X/Z
concentration of 4-nitrophenoxide ion in the initial
period of the reaction. It is known [10] that selectivity
constants often depend upon ion concentration.
Here, b is a parameter which is constant within the
given data array; and k2-ph is the apparent rate con-
stant analogous to k2-ph in Eq. (1) but determined by
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 38 No. 3 2002

EFFECT OF THE STRUCTURE OF PHASE-TRANSFER CATALYST
approximation under the constraint that b does not
381
change whithin the series of kinetic measurements for
a single catalyst. The values of b for catalysts IV VI
were thus estimated at 0.17 0.02, 0.15 0.01, and
0.16 0.01, respectively. It is seen that these values
coincide with each other within the mean-square
deviation. The rate constants k2-ph given in table also
coincide with k2-ph. Figure 2 shows the results of
approximation for the whole array of experimental
data. In the region of substrate conversion up to 80%
a normal dispersion of points with respect to the
straight line with a unit slope is observed. At higher
conversions, a tendency to autoacceleration appears.
The reasons for the observed pattern are still not clear.
The low rate of the reaction in the initial period
may also be explained in terms of microtopology of
the chemical process. As noted above, we believe that
the process follows extraction mechanism. The latter
implies that the reaction can occur both at the phase
boundary (at the side of organic phase) or in the bulk
organic phase [2, 11]. Preliminary stirring of a solu-
tion of phase-transfer catalyst QZ with aqueous buffer
solution in a two-phase system could lead (depending
on the counterion Z) to increased concentration of
OH ions at the phase boundary and in the boundary
layer, as compared to its quasistationary concentration
which establishes during the process. Therefore, the
reaction in the boundary layer in the initial period
(after addition of the ester) may be faster.
Fig. 2. Correlation between ln[a/(a x)]exp values calcu-
lated from the experimental data and ln[a/(a x)]calc values
approximated by Eq. (1 ) for phase-transfer catalysts
(1) IV, N = 151; (2) V, N = 158; and (3) VI, N = 129; N is
the number of points.
According to our previous data [4, 5], the reaction
is of first order with respect to hydroxide ion con-
centration in the aqueous phase ([OH ]aq). Then, for
a given catalyst concentration the rate constant k2-ph
is expressed by Eq. (2):
k2-ph = k
[OH]aq,
(2)
2-ph
OH
where k2-ph (l mol 1 s ) is the apparent second-order
1
rate conOstHant which is a function of concentration of
phase-transfer catalyst. Figure 3 shows the dependence
2-ph
OH
of k
on the overall catalyst concentration in the
two-phase system. This dependence is generally non-
linear, which is typical of phase-transfer processes.
Estimation of the slopes at the initial part of the
above dependences gave tan values which may be
regarded as an integral parameter characterizing the
efficiency of phase-transfer catalyst:
2-ph
Fig. 3. Dependence of k
on the overall concentration
OH
of phase-transfer catalyst: (1) VI, (2) V, (3) IV.
Worthy of note is insignificant difference in the
activity of chloride and bromide salts having the same
or similar cationic part (cf. Ia and Ib, III and IV).
As previously [5], this fact is explained in terms of
competing extraction of the catalyst counterion and
4-nitrophenoxide ion formed: transfer of the latter
into the organic phase predominates. On the other
Catalyst
tan
I [5], Z = Br
I [5], Z = Cl
II [6]
10
650
890
Catalyst
tan
III [6]
1600
IV
1400
V
110
VI
110
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 38 No. 3 2002

382
BARANOVA et al.
activity of salts having a heteroaromatic cation in
processes following the extraction mechanism. The
same applies to N-alkylpyridinium salts having strong
electron-acceptor substituents in the pyridine ring [12].
The alkaline hydrolysis of N-benzyloxycarbonyl-
glycine 4-nitrophenyl ester in the presence of N-hexa-
decylpyridinium chloride should be considered separ-
2-ph
OH
ately. In this case, an extremal dependence of k
on the catalyst concentration is observed (Fig. 3,
curve 2), which is typical of micelle catalysis in
aqueous solution [13]. Starting from a concentration
3
of 8 10 M, the reaction rate sharply increases,
2
reaching a maximum at ccat
=
1.2 10 M. After
that, the reaction rate falls down as sharply as it rose
before. Had that part been cut from the plot (Fig. 3,
curve 2, dashed line), the dependence would be
similar to those obtained for salts IV, VI, and I III
[5, 6]. These data suggest that the acceleration effect
produced by catalyst V originates from at least two
factors: (1) phase-transfer catalysis of hydrolysis with
chemical reaction in the organic phase as the rate-
determining stage (extraction mechanism) throughout
the range of variation of the salt concentration and
(2) micelle formation in the aqueous phase in the
region of critical micelle concentration (CMC).
Fig. 4. Dependences of (1) the distribution coefficient of
N-hexadecylpyridinium cation (E = corg/caq) and (2) pseudo-
first-order rate constant k2-ph on the overall concentration
of hexadecylpyridinium chloride in the two-phase system
chloroform borate buffer (pH 10); 25 C.
Figure 4 (curve 1) shows the dependence of the
distribution coefficient of N-hexadecylpyridinium
chloride E = corg/caq versus its overall concentration
(calculated on the entire volume of the two-phase
system). It is seen that the dependence also passes
through a maximum located approximately in the
same range of concentrations as for the reaction rate
peak (Fig. 4, curve 2). The experimental concentration
of N-hexadecylpyridinium cation in the aqueous
phase at the midpoint (ccat = 0.01 M) was estimated at
3
(1.6 1.8) 10 M. This value approaches the critical
micelle concentration of the salt in water (0.9 10 3 M
[14]). We can thus presume that micelle catalysis in
the aqueous phase is responsible for increase of the
reaction rate in the two-phase system in range of salt
V concentrations from 0.8 10 to 1.2 10 M.
On the other hand, the dependence of E on the con-
centration of salt V in the two-phase system (Fig. 4,
Fig. 5. Dependence of the pseudofirst-order rate constant
in the separated (1) aqueous phase, kaOqH, and (2) organic
phase, kOorHg, on the overall concentration of N-hexadecyl-
pyridinium chloride.
2
2
hand, the efficiency of phase-transfer catalysts in the curve 1) implies that another explanation is possible,
reaction under study strongly depends on the cation
nature. Among lipophilic compounds II VI the most
active are imidazolium salts III and IV. Unfortu-
nately, we have no data on distribution of these salts
in systems water organic solvent; therefore, it is
impossible to correlate the catalytic activity with
extractibility of the respective cations. The available
data allow us only to state the fact of high catalytic
namely in terms of increased extraction of the salt
cation into the organic phase. Obviously, N-hexa-
decylpyridinium cation can be transferred to organic
phase as ion pair not only with hydroxide ion but also
with chloride ion as counterion. In order to check the
possibility for increased extraction of hydroxide ion
into organic phase, we examined the kinetics of
alkaline hydrolysis of N-benzyloxycarbonylglycine
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 38 No. 3 2002

EFFECT OF THE STRUCTURE OF PHASE-TRANSFER CATALYST
383
4-nitrophenyl ester in the separated aqueous and
organic phases on variation of the catalyst concentra-
tion. Figure 5 shows the dependences of the apparent
pseudofirst rate constants in the separated aqueous
the optical density at
(accumulation of 4-nitrophenoxide ion).
410 nm was measured
Distribution of N-hexadecylpyridinium cation.
Equal volumes of chloroform and borate buffer were
mixed, N-hexadecylpyridinium chloride was added,
and the mixture was stirred for at least 15 min at
25 C. The phases were separated by centrifugation,
and the concentration of N-hexadecylpyridinium ion
in each phase was determined by spectrophotometry
aq
org
(k ) and organic phases (k ) on the concentration
OH
OH
of salt V. The dependences obtained for the separated
phases are qualitativly similar with that observed in
the two-phase system (cf. Fig. 5 and Fig. 4, 2), i.e. all
these pass through a maximum. This means that in
the region of critical micelle concentration, extraction
of hydroxide ion into the organic phase sharply in-
creases, which can give rise to the observed jump
of the reaction rate.
It is difficult to speak unequivocally which factors
or interactions in the system in the region of CMC are
responsible for acceleration of the process. Among
these, the following should be noted: (1) variation of
the solvation energy ratio of Cl and OH ions due
to predominant binding of one kind of ions to micelle
surface in the aqueous phase; (2) formation in the
organic phase of structurized ionic species (up to
reverse micelle-like structures) which retain OH ions
better than in ion pairs; (3) a different mechanism of
anion exchange between the phases; etc.
To conclude, we can state that organic salts having
a heterocyclic moiety in the cationic part exhibit the
highest catalytic effect in the alkaline hydrolysis of
N-benzyloxycarbonylglycine 4-nitrophenyl ester in
the two-phase system chloroform borate buffer. This
fact, together with our previous findings [5], provides
an additional support to the extraction mechanism of
the reaction under study.
at
260 nm.
N-Benzyloxycarbonylglycine 4-nitrophenyl ester
was synthesized and purified as described in [16],
mp 127 C; published data [16]: mp 126 128 C.
Solvents were purified by standard procedures [17].
3-Hexadecyl-1-methylimidazolium chloride (IV).
A mixture of 0.06 mol of hexadecyl chloride and
0.062 mol of 1-methylimidazole was heated for 20
30 h at 100 C (water bath) in a sealed ampule. When
the reaction was complete (the mixture usually crys-
tallized), trace amounts of unreacted initial com-
pounds were removed by heating the product in
a mixture of acetone with methanol under reflux. The
salt was filtered off, recrystallized from acetone
methanol, and dried in a vacuum desiccator over P2O5,
mp 59.5 61 C. Found, %: C 70.00; H 11.30;
Cl 10.30; N 8.20. C20H38ClN2. Calculated, %:
C 70.07; H 11.39; Cl 10.36; N 8.18.
N-Hexadecylpyridinium chloride (V) was purified
by the procedure described in [18], mp 81 82 C;
published data [18]: mp 80 83 C.
1-Dodecyl-1,1-dimethylhydrazinium chloride
(VI). A mixture of 15.2 ml (0.2 mol) of 1,1-dimethyl-
hydrazine and 52.82 ml (0.22 mol) of dodecyl
chloride was heated for 11 h at 60 C. Diethyl ether,
30 ml, was added, the mixture was ground, and the
precipitate was filtered off. Yield of salt VI 24.4 g
(94%). mp 80 82 C (from toluene; the melt became
EXPERIMENTAL
The kinetic measurements were performed using
an SF-26 spectrophotometer; pH values were
measured with the aid of an EV-74 ionometer. Stand-
ard borate buffer was prepared by the procedure
described in [15]. The reaction kinetics in the two-
phase system were studied following the procedure
reported in [5]. The reaction rates in the separated
organic and aqueous phases were measured as follows.
Equal volumes of chlorofom and borate buffer were
mixed in a vessel maintained at a specified tempera-
ture, and a required amount of the catalyst was added.
The mixture was stirred for at least 15 min at 25 C,
and the organic and aqueous phases were separated by
centrifugation at 3000 rpm. The separated phase was
placed in a spectrophotometric cell maintained at
a specified temperature, a solution of N-benzyloxy-
carbonylglycine in dioxane was added dropwise, and
1
perfectly transparent at 150 C). H NMR spectrum
(DMSO-d6): 0.90 t (CH3C), 1.22 m (2H, CH2C),
1.75 m (2H, CH2CN), 3.24 s (6H, CH3N), 3.48 m
(2H, CH2N), 6.25 s (2H, NH2). Found, %: C 63.7;
H 12.4; N 10.7; Cl 13.3. C14H33ClN2. Calculated, %:
C 63.5; H 12.6; N 10.6; Cl 13.4.
Tetraethylammonium chloride (VII) was purified
by the procedure described in [19]. Benzyltriethyl-
ammonium chloride VIII was purified by the proce-
dure described in [20], mp 194.5 195 C; published
data [21]: mp 195 C.
1,2-Bis(1,1-dimethyl-1-hydrazinio)ethane di-
bromide (IX) [21] was synthesized as desribed above
for salt VI from 30.4 ml (0.2 mol) of 1,1-dimethyl-
hydrazine and 9.9 g (0.1 mol) of 1,2-dibromoethane.
The mixture was heated for 4 h at 50 C or for 3 h at
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 38 No. 3 2002

384
BARANOVA et al.
60 C. Yield of salt IX 17.1 g (78%). mp 214 216 C
(from methanol 2-propanol, 1:1). Found, %: C 28.8;
H 7.4; Br 47.2; N 16.5. C8H24Br2N4. Calculated, %:
C 28.6; H 7.2; Br 47.5; N 16.7.
3-(2,2,2-Trimethyl-1-hydrazinio)propanoate di-
hydrate (X) was synthesized by the known procedure
for preparation of Mildronat [22], starting from acrylic
acid esters and 1,1-dimethylhydrazine, mp 254
255 C; published data [22]: mp 254.6 C.
6. Kosmynin, V.V., Baranova, O.V., and Vakhito-
va, L.N., Abstracts of Papers, Vuzovskaya konferen-
tsiya professorsko-prepodavatel’skogo sostava po
itogam nauchno-issledovatel’skoi i metodicheskoi
raboty: khimiya, biologiya (Institution Conf. of
the Teaching Staff on the Results of Research and
Methodical Works: Chemistry and Biology),
Donetsk, 1995, p. 52.
7. Herriot, A.W. and Picker, D., J. Am. Chem. Soc.,
1975, vol. 97, no. 9, pp. 2345 2349.
1,1-Dimethyl-1-hyidrazinioethanoate (XI). A so-
lution of 1.11 ml (0.01 mol) of ethyl bromoacetate
and 2.37 ml (0.03 mol) of 1,1-dimethylhydrazine in
5 ml of acetonitrile was refluxed for 1 h (the conver-
sion of the ester was complete). The solution was
evaporated to dryness, the precipitate of 1,1-dimethyl-
1-ethoxycarbonylmethylhydrazinium bromide was
dissolved in a mixture of 10 ml of methanol and
5 ml of water, and the solution was passed through
a column charged with AV-17-8 anion exchanger (in
the OH-form). The resulting solution was evaporated
under reduced pressure, and the residue was recrystal-
lized from water. Yield 1.1 g (93%), mp 236 238 C
8. Halpern, M., Sasson, Y., and Rabinovitz, M., Tetra-
hedron, 1982, vol. 38, no. 21, pp. 3183 3187.
9. Gol’dberg, Yu.Sh., Abele, E.M., Kalvin’sh, I.Ya.,
et al., Dokl. Akad. Nauk SSSR, 1987, vol. 294, no. 6,
pp. 1387 1389.
10. Starks, C.M. and Owens, R.M., J. Am. Chem. Soc.,
1973, vol. 95, no. 11, pp. 3613 3617.
11. Yufit, S.S. and Zinov’ev, S.S., Russ. J. Org. Chem.,
1998, vol. 34, no. 9, pp. 1222 1225.
12. Phase-Transfer Catalysis. New Chemistry, Catalysts,
and Applications, Starks, C.M., Ed., Washington:
Am. Chem. Soc., 1987. Translated under the title
Mezhfaznyi kataliz. Khimiya, katalizatory i prime-
nenie, Moscow: Khimiya, 1991, pp. 38 49.
1
(from 2-propanol). H NMR spectrum (DMSO-d6):
3.20 s (6H, CH3N), 3.65 s (2H, CH2N), 6.51 s (2H,
NH2). Found, %: C 40.5; H 8.6; N 23.4. C4H10N2O2.
Calculated, %: C 40.7; H 8.5; N 23.7.
13. Fendler, E. and Fendler, J., Advances in Physical
Organic Chemistry, Gold, V., Ed., London:
Academic, 1970, vol. 8, pp. 271 406. Translated
under the title Metody i dostizheniya fiziko-organi-
cheskoi khimii, Moscow: Mir, 1973, pp. 222 224.
3-(1,1-Dimethyl-1-hydrazinio)propanesulfonate
(XII) was synthesized as described above for salt VI
from 3.8 ml (0.05 mol) of 1,1-dimethylhydrazine and
6.1 g (0.05 mol) of propanesulfonate. Reaction time
3 h. Yield 7.9 g (87%). mp 283 284 C (from DMF).
1H NMR spectrum (DMSO-d6): 1.82 s (2H, CH2C),
3.17 s (6H, CH3N), 3.30 m (2H, CH2N), 3.50 m (2H,
CH2S), 4.40 br.s (2H, NH2). Found, %: C 33.3;
H 7.7; N 15.3; S 17.9. C5H14N2O3S. Calculated, %:
C 33.0; H 7.7; N 15.4; S 17.6.
14. Poverkhnostno-aktivnye veshchestva. Spravochnik
(Surface Active Substances. Handbook), Abram-
zon, A.A. and Gaevoi, G.M., Eds., Leningrad:
Khimiya, 1979, p. 197.
15. Spravochnik khimika (Chemist’s Handbook), Nikol’-
skii, B.P., Ed., Moscow: Khimiya, 1964, vol. 3,
p. 173.
16. Kosmynin, V.V., Sharanin, Yu.A., and Litvinen-
ko, L.M., Zh. Org. Khim., 1972, vol. 8, no. 1,
pp. 3 7.
17. Gordon, A.J. and Ford, R.A., The Chemist’s Compa-
nion, New York: Wiley, 1972. Translated under the
title Sputnik khimika, Moscow: Mir, 1976, pp. 437
444.
18. Metody polucheniya khimicheskikh reaktivov i pre-
paratov (Methods of Preparation of Chemicals),
Moscow: IREA, 1964, pp. 105 107.
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RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 38 No. 3 2002