Synthesis and characterization of novel ionic liquids: N-substituted aziridinium salts

Article abstract of DOI:10.1002/jhet.876

Ionic liquids based on three-membered ring aziridinium cations have been synthesized for the first time using a straightforward synthetic route. N-butyl-N-methylaziridinium bis(trifluoromethanesulfonyl)imide, N-propyl-N-ethylaziridinium bis(trifluoromethanesulfonyl)imide, N-butyl-N-[2-(2-methoxyethoxy)ethyl]aziridinium bis(trifluoromethanesulfonyl) imide, N-butyl-N-methylaziridinium dicyanamide, and N-butyl-N-ethylaziridinium dicyanamide were thus obtained in good yields and satisfactory purity and fully characterized.

Full text of DOI:10.1002/jhet.876

652
Synthesis and Characterization of Novel Ionic Liquids:
N-Substituted Aziridinium Salts
Vol 49
Martin B. Duriska, Joseph Grondin, Laurent Servant, Marc Birot,
*
and Hervé Deleuze
Université de Bordeaux, Institut des Sciences Moléculaires, Talence F-33405, France
*
E-mail: h.deleuze@ism.u-bordeaux1.fr
Received November 24, 2010
DOI 10.1002/jhet.876
View this article online at wileyonlinelibrary.com.
Ionic liquids based on three-membered ring aziridinium cations have been synthesized for the first time
using a straightforward synthetic route. N-butyl-N-methylaziridinium bis(trifluoromethanesulfonyl)imide,
N-propyl-N-ethylaziridinium bis(trifluoromethanesulfonyl)imide, N-butyl-N-[2-(2-methoxyethoxy)ethyl]aziri-
dinium bis(trifluoromethanesulfonyl)imide, N-butyl-N-methylaziridinium dicyanamide, and N-butyl-N-
ethylaziridinium dicyanamide were thus obtained in good yields and satisfactory purity and fully characterized.
J. Heterocyclic Chem., 49, 652 (2012).
INTRODUCTION
decrease of the specific energy of the battery and overall
performance [21,22]. Therefore, the search for new electro-
lyte systems and optimization of conventional electrolytes
is an important research area in the Li battery industry.
Room temperature ionic liquids (RTILs) have advantages
of nonflammability, high electrochemical stability, and
negligible vapor pressure [23–25]. Application of RTILs
as electrolytes in Li-ion batteries may completely solve
the safety problems [26–28] and suppress the strong inter-
facial reactions. 1-Ethyl-3-methylimidazolium-based IL
electrolytes have the virtue of low viscosity and high con-
ductivity. However, practical application of imidazolium
RTILs in 4 V Li-ion batteries seems to be difficult because
of their narrow electrochemical window (ca. 4.2 V) to with-
stand cathodic reduction and anodic oxidation [29]. ILs with
more stable cations such as cyclic tetraalkylammonium
show wider electrochemical windows (often more than
5 V) [30–32]. An ionic liquid capable of operating as sup-
porting electrolyte for 4-V-class rechargeable Li batteries
must have the following properties: (i) a low melting point
to operate over a wide range of temperature, (ii) a weakly
coordinating nature for its anion to depress ion pairing,
(iii) a low viscosity at room temperature to enhance the
mobility of ionic species, and (iv) a large electrochemical
window that allows the Li+/Li redox reaction taking place
in both the anode and the cathode sides to be reversible.
Ionic liquids (ILs) are room temperature fluids consti-
tuted of a bulky and asymmetric organic cation associated
with a small organic or inorganic anion. Interests in
ILs have steadily grown in recent years, because their
unique solvent properties provide the possibility for clean
manufacturing in chemical industry [1–3]. Regularly, vari-
ous publications and patents report novel applications of
ILs such as catalytic synthesis [4–7], separation [8–11],
polymerization [12], nanotechnology [13], biocatalysis
[14,15], composite preparation [16], and renewable re-
source utilization [17,18]. To date, there have been numer-
ous commercial applications since BASF’s (Badische
Anilin und Soda-Fabrik) first successful use of an IL in
2003 [19]. Because of their unique physicochemical prop-
erties [20] ionic liquids have been regarded as promising
candidates for lithium battery electrolytes. Conventional
nonaqueous organic electrolytes are widely used in com-
mercial Li-ion batteries, however, these organic solvents
are volatile and in many cases highly flammable. Li-ion
batteries using these electrolytes can become dangerous
when subjected to extreme conditions. Furthermore,
because of insufficient electrochemical stability electrolyte
decomposition may occur, accompanied by an irreversible
consumption of electrolyte and lithium, which leads to a
© 2012 HeteroCorporation

May 2012
Synthesis and Characterization of Novel Ionic Liquids: N-Substituted Aziridinium Salts
653
Scheme 1. Synthesis of N-alkylaziridines.
Concerning the anion, the bis(trifluoromethanesulfonyl)
imide ion ([(CF3SO2)2N)]ꢀ, TFSI) has been mentioned as
a promising candidate because of both its electrochemical
stability and its weakly coordinating capability [30].
Concerning the viscosity lowering, the dicyanamide ion
([(CN)2N]ꢀ, DCA) also appears to be promising [33].
The length of the alkyl arms brought by the nitrogen atom
of the heterocyclic ring of the cation has also influence on
the above properties. As a rule, the alkyl groups should
have lengths different enough to avoid cation symmetry,
whereas maintaining a small ion size to favor low viscosity
[34]. Furthermore, introduction of oxygen atoms in the
alkyl side-chains is also known to lower the IL’s viscosity
in the case of cyclic quaternary ammonium cations [31].
Recent research has also focused on the ILs for electric
double-layer capacitors, usually named supercapacitors.
Although batteries store energy in chemical reactions,
capacitors store it in surface charges, so they can provide
rapid bursts of power. Such power storage devices, when
involving porous materials with high surface areas serving
as electrodes, fill the gap between dielectric capacitors and
traditional batteries, and usually require salts dissolved in a
solvent having a high dielectric constant. However, the use
of solvent-free ILs enables to reach the high cell voltages
necessary for increasing energy.
temperature under vacuum to give the inner salt of the
sulfate ester. This intermediate was then treated in situ with
a concentrated solution of sodium hydroxide from which
the corresponding N-alkylaziridine was collected by steam-
distillation as a pure product (Scheme 1). N-butyl- and N-
ethylaziridines were synthesized using this procedure with
moderate but reproducible yields.
N-alkyl-N-alkyl0-aziridinium iodides were synthesized
by a modification of the Graetzel’s quaternization method
[44]. An alkyliodide and a slight excess of N-alkylaziridine
were mixed and stirred at room temperature without sol-
vent. Evaporation under vacuum of the excess of aziridine
gave high yield of the pure expected compounds (Scheme 2).
2-(2-Methoxyethoxy)ethyl iodide was synthesized in two
steps from 2-(2-methoxyethoxy)ethanol (Scheme 3).
N-Alkyl-N-alkyl0-aziridinium TFSI ILs were synthe-
sized by mixing two equimolar aqueous solutions of
N-alkyl-N-alkyl0-aziridinium iodide and lithium TFSI
according to a published method with modification
[30]. N-Alkyl-N-alkyl0-aziridinium DCA ILs were syn-
thesized by mixing an aqueous solution of N-alkyl-N-
alkyl0-aziridinium iodide and silver dicyanamide
(AgDCA) according to a published method with modifi-
cations (Scheme 4; ref. [41]).
Using this methodology, five ILs have been synthe-
sized: N-butyl-N-methylaziridinium TFSI, N-propyl-N-
ethylaziridinium TFSI, N-butyl-N-[2-(2-methoxyethoxy)
ethyl]aziridinium TFSI, N-butyl-N-methylaziridinium
DCA, and N-butyl-N-ethylaziridinium DCA.
The physicochemical data of these compounds are
reported in Table 1. The structure and composition of the
salts prepared were confirmed by elemental analysis and
by NMR spectroscopy. The thermal properties of the salts
prepared were characterized by differential scanning calo-
rimetry (mp). For salts that are liquid at room temperature,
their dynamic viscosity (Z) and ionic conductivity (s) were
measured at 25ꢁC. Electrochemical windows ΔE were also
determined.
One of the more promising classes of ILs as electrolytes
seems to be that containing the N-methyl-N-alkylpiperidinium
and pyrrolidinium cations [31]. Application of these ionic
liquids into Li-ion batteries seems to be more practical
[35–38]. In this paper, we synthesized several new ILs
based on three-membered ring aziridinium cations to
compare their electrochemical properties with their five-
membered ring pyrrolidinium homologs.
RESULTS AND DISCUSSION
The preparation of N-Alkyl-N-alkyl0-aziridinium ions
has been scarcely reported in the literature [39] because
of the lack of general synthetic access to their precursor
N-alkylaziridine [40]. However, N-butylaziridine may con-
veniently be prepared by cyclization of the corresponding
2-(butylamino)ethanol [41,42]. As large quantities of
N-alkylaziridines were required in this work, an efficient
laboratory procedure was developed from commercially
available 2-(alkylamino)ethanols by modification of the
Wenker’s general method [43]. A 2-(alkylamino)ethanol
was treated with concentrated chlorosulfonic acid at high
Scheme 2. Synthesis of the N-alkyl-N-alkyl0-aziridinium iodides.
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

654
M. B. Duriska, J. Grondin, L. Servant, M. Birot, and H. Deleuze
Vol 49
Scheme 3. Synthesis of 2-(2-methoxyethoxy)ethyl iodide.
Scheme 4. Synthesis of N-alkyl-N-alkyl0-aziridinium ionic liquids.
N-butyl-N-methylpyrrolidinium TFSI. A Whatman GF/A
separator was plunged in the electrolyte and sandwiched
between two identical immersed carbon fabrics (9 mm in
diameter; 1700 m2 gꢀ1) acting as composite electrodes.
The cell was assembled in a glove box under argon atmo-
sphere. The assembled cell was charged (discharged) by
applying a constant voltage: 2 V (0 V). The capacitance
was evaluated from the charge curve. The capacitance of
The data reported in Table 1 indicate that some of
the aziridinium-based ILs synthesized are liquid at room
temperature with quite low melting points. However, their
viscosities are relative high (on comparison with N-butyl-
N-methylpyrrolidinium TFSI). As a direct consequence,
the conductivity is low (this value depends on the ions
mobility). Furthermore, the electrochemical windows,
situated around 2 V, are too narrow to be useful in battery
applications. This quite disappointing behavior may be
attributed to the flat nature of the aziridine ring favoring
some stacking of the molecules. A molecular modeling
such as that conducted on linear quaternary ammonium
IL [45] would probably be useful.
Further, to investigate the potentiality of the newly syn-
thesized aziridinium-based ILs, we examined the perfor-
mances of a double-layer capacitor composed of a pair of
activated carbon fabrics as electrodes and N-butyl-N-[2-
(2-methoxyethoxy)ethyl]aziridinium TFSI, which was
compared with the commonly used nonaqueous electrolyte
the aziridinium-based cell was estimated at 160 mC cmꢀ2
whereas that of the N-butyl-N-methylpyrrolidinium TFSI cell
was measured at 820mC cmꢀ2
,
.
CONCLUSIONS
In this work, we have synthesized representative com-
pounds of a new family of room temperature ionic liquids
built from three-membered ring aziridinium cations. The
reactions involved were straightforward and efficient with
only a few by-products. The anions used were the weakly
coordinating TFSI and DCA. The high viscosities and nar-
row electrochemical windows of these new ionic liquids
restrict their potentials as electrolytes in Li-ion batteries
and in supercapacitors. However, applications in catalysis
or extraction may be found for this new class of ionic
liquids.
Table 1
Physicochemical properties of synthesized aziridinium-based ILs.
mpa (ꢁC)
Zb (cP)
sc (mS cmꢀ1
)
Ec (V)
Ea (V)
ΔE (V)
N-Butyl-N-methylpyrrolidinium TFSId
N-Butyl-N-methylaziridinium TFSI
ꢀ19
53
76
–
2.6
–
ꢀ3.0
–
+2.0
–
5.0
–
N-Propyl-N-ethylaziridinium TFSI
129
ꢀ60
ꢀ25
ꢀ49
–
–
–
–
+0.5
–
–
2.0
–
N-Butyl-N-[2-(2-methoxyethoxy)ethyl]aziridinium TFSI
N-Butyl-N-methylaziridinium DCA
N-Butyl-N-ethylaziridinium DCA
650
1050
320
0.21
0.40
0.60
ꢀ1.5
–
ꢀ1.7
+0.7
2.4
aMelting point.
bViscosity at 25ꢁꢁC.
cSpecific conductivity at 25ꢁꢁC.
dData obtained from the literature [31].
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

May 2012
Synthesis and Characterization of Novel Ionic Liquids: N-Substituted Aziridinium Salts
655
N-Propyl-N-ethylaziridinium iodide. N-Ethylaziridine (42 mmol,
3.0 g) was mixed with iodopropane (38 mmol, 6.5 g) and stirred for 24
h at room temperature. After this time, the reaction volume was
reduced under high vacuum (1 mmHg) leaving the desired product
as a white solid (8.7 g, 95%). dH(DMSO): 3.75 (4H, s), 3.57 (2H,
m), 3.40 (2H, m), 1.63 (2H, m), 1.23 (3H, m), 0.95 (3H, m).
Found: C, 34.55; H, 7.01; N, 5.12; I, 52.42. Calc. for C7H16NI: C,
34.87; H, 6.69; N, 5.85; I, 52.63%.
EXPERIMENTAL
Reagents and methods All solvent were freshly distilled
from the appropriate reagents before use. The alkyl iodides, 2-
(butylamino)ethanol, 2-(ethylamino) ethanol, chlorosulfonic
acid, 2-(2-methoxyethoxy)ethanol, p-toluenesulfonyl chloride,
and lithium bis(trifluoromethanesulfonyl)imide were purchased
from Sigma–Aldrich Chemical (Lyon, France) and used
without further purification. Unless otherwise specified, all
manipulations were carried out on a double manifold Schlenk
vacuum line under an atmosphere of nitrogen.
N-Butyl-N-ethylaziridinium iodide. N-Ethylaziridine (42 mmol,
3.0 g) was mixed with iodobutane (36 mmol, 6.6 g) and stirred
for 24 h at room temperature. After this time, the reaction
volume was reduced under high vacuum (1 mmHg) leaving the
desired product as a white solid (8.7 g, 95%). dH(DMSO): 3.71
(4H, m), 3.51 (2H, m), 3.28 (2H, m), 1.63 (2H, m), 1.30
(2H, m), 1.23 (3H, t), 0.97 (3H, t). Found: C, 36.96; H, 6.85;
N, 5.72; I, 49.37. Calc. for C8H16NI: C, 37.66; H, 7.11; N,
5.49; I, 49.74%.
1H-NMR (300 MHz, Me4Si) and 13C-NMR (150 MHz, Me4Si)
spectra were collected using a Bruker ADX-300 spectrometer.
J values are given in Hz. Infrared spectra were obtained using a
Perkin-Elmer Spectrum 100 Spectrometer. Microanalyses were
conducted at the CNRS Service Central d’Analyse, France.
Melting points were determined using differential scanning
calorimetry in a Perkin-Elmer Pyris 1 DSC equipped with a liquid
nitrogen cryostatic cooling. An average sample weight of 5–10 mg
was sealed in an aluminum pan and quenched initially to ꢀ100ꢁC,
2-(2-Methoxyethoxy)ethyl iodide. 2-(2-Methoxyethoxy)ethanol
(0.54 mol, 65 g) was dissolved in dry ether (500 mL), and powdered
potassium hydroxide (0.5mol, 28 g) and p-toluenesulfonyl chloride
(0.5 mol, 95.3 g) were added. The suspension was vigorously stirred
at room temperature for 10 h under nitrogen. The mixture was then
filtered, and the filtrate washed with water (3 ꢂ 50 mL) then
dried under MgSO4 before concentrating under vacuum to
leave raw 2-(2-methoxyethoxy)ethyl-p-toluene sulfonate (118 g,
86%). This product (118 g, 0.43 mol) was dissolved in dry
acetone (250mL) and sodium iodide (0.5 mol, 75 g) was
added. The solution was stirred at room temperature under
nitrogen in the dark for 24 h. The solvent was evaporated
under vacuum to give a colorless liquid that was distilled
(82 g, 77%; Eb = 120ꢁC at 20 mmHg) [40]. dH(CDCl3):
3.28 (2H, t), 3.42 (3H, s), 3.55 (2H, t), 3.68 (2H, t), 3.75
(2H, t). Found: C, 26.50; H, 4.11; I, 55.42. Calc. for
C5H11O2I: C, 26.10; H, 4.82; O, 13.91; I, 55.16%.
and then heated at a rate of 5ꢁC minꢀ1
.
Dynamic viscosities (Z) were measured with a Brookfield
viscosimeter (model DV-III+) using 1 mL sample at 25ꢁC.
Specific ionic conductivities (s) were measured by a conduc-
tivity meter (Radiometer Analytical, model CDM230) in a sealed
conductivity cell at 25ꢁC.
The cathodic and anodic limits, Ec and Ea (V), versus ferrocene
(Fe)/ferrocenium (Fc+) redox couple were investigated by linear
sweep voltammetry on a glassy carbon electrode.
N-Butylaziridine. Chlorosulfonic acid (213 mmol, 25 g) was
placed into a round bottomed flask and cooled to 0ꢁC in an ice
bath. 2-(Butylamino)ethanol (213 mmol, 25 g) was placed in a
dropping funnel and added slowly to the acid while maintaining
the temperature at 0ꢁC. After the addition, the mixture was
heated to 150ꢁC under vacuum for 2 h. The reaction was
cooled, and water (30 mL) was added followed by an aqueous
solution of potassium hydroxide (60 g of KOH in 60 mL of
water). The alkaline solution was gently heated to ∼120ꢁC and
the desired product that distilled off was collected as a light
yellow mobile oil (12.3 g, 58%). Eb = 100–105ꢁC [41].
dH(DMSO): 2.08 (2H, t, J = 7.1), 1.52 (2H, m), 1.42
(2H, m), 1.33 (2H, m), 1.00 (2H, m), 0.87 (3H, t, J = 7.2).
dC(DMSO): 62.2, 30.0, 28.1, 21.4, 14.8. Found: C, 72.37; H,
13.35; N, 14.23. Calc. for C6H13N: C, 72.67; H, 13.21; N,
14.12%.
N-Butyl-N-[2-(2-methoxyethoxy)ethyl]aziridinium iodide.
N-Butylaziridine (200 mmol, 19.8 g) was added to 2-(2-
methoxyethoxy)ethyl iodide (180 mmol, 41 g), and the
reaction was stirred for 24 h at room temperature. After this
time, the reaction volume was reduced under high vacuum
(1 mmHg) for 24 h resulting in a white solid (57 g, 96%).
dH(CDCl3): 3.73 (4H, m), 3.52 (2H, t), 3.35 (2H, m), 3.29
(2H, t), 3.27 (2H, t), 3.19 (2H, t), 1.63 (2H, m), 1.26 (2H,
m), 1.23 (3H, t), 0.95 (3H, t). Found: C, 40.23; H, 7.36; N,
4.50; I, 38.22. Calc. for C11H24NO2I: C, 40.13; H, 7.35; N,
4.25; O, 9.72; I, 38.55%.
N-Ethylaziridine. N-Ethylaziridine was obtained using a
similar procedure as described for N-butylaziridine (7.2 g,
46%). Eb = 45–50ꢁC. dH(DMSO): 2.11 (2H, q, J = 7.1),
1.52 (2H, m, J = 2.3), 1.03 (3H, t, J = 7.1), 0.99 (2H, m,
J = 2.3); dC(DMSO): 57.3, 27.1, 14.5. Found: C, 67.23; H,
12.91; N, 19.51. Calc. for C4H9N: C, 67.55; H, 12.75; N,
19.69%.
N-Butyl-N-methylaziridinium iodide. N-Butylaziridine
(20 mmol, 2.0 g) was cooled in an ice bath and iodomethane (18
mmol, 2.5 g) was slowly added while stirring. Following the
addition, the reaction was stirred for 24 h at room temperature. After
this time the reaction volume was reduced under high vacuum (1
mmHg), leaving the desired product as a white solid (4.1 g, 95%).
dH(DMSO): 3.66 (4H, m), 3.52 (2H, m), 3.25 (3H, s), 1.63 (2H, m),
1.26 (2H, m), 0.92 (3H, t). Found: C, 34.50; H, 6.23; N, 5.85; I,
52.67. Calc. for C7H16NI: C, 34.87; H, 6.69; N, 5.85; I, 52.63%.
N-Butyl-N-methylaziridinium bis(trifluoromethanesulfonyl)
imide. N-Butyl-N-methylaziridinium iodide (15.3 mmol, 3.7 g)
was dissolved in distilled water (100 mL), and lithium bis
(trifluoromethanesulfonyl)imide (15.3 mmol, 4.4 g) dissolved in
water (20 mL) was added. The solution was vigorously stirred for
1 h then allowed to stand. A pale yellow phase, which separated
from the water layer, was collected and washed three times with
distilled water. The ionic liquid product was dissolved in ethanol
and passed through a plug of basic alumina and charcoal. The
liquid volume was reduced under high vacuum (1 mmHg) for 1
week and the final product stored under dry nitrogen (5.8 g, 96%).
dH(DMSO): 3.66 (2H, m), 3.52 (2H, m), 3.25 (2H, m), 3.01
(3H, s), 1.63 (2H, m), 1.26 (2H, m), 0.92 (3H, t). Found: C,
27.71; H, 4.23; N, 7.41; S, 15.61; F, 28.53. Calc. for
C9H16N2O4F6S2: C, 27.41; H, 4.09; N, 7.10; O, 16.23; S, 16.26;
F, 28.90%.
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M. B. Duriska, J. Grondin, L. Servant, M. Birot, and H. Deleuze
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N-Propyl-N-ethylaziridinium bis(trifluoromethanesulfonyl)
Acknowledgments. M.B.D. thanks CNRS for financial support.
B. Grassl of the IPREM (UPPA) is acknowledged for viscosity
measurements. We are grateful to Julia Willer, from Kynol
Europa, for providing us Kynol activated carbon fabrics.
imide. N-Propyl-N-ethylaziridinium iodide (8.3 mmol, 2.0 g) was
dissolved in water (25 mL) and a solution of lithium bis
(trifluoromethanesulfonyl)imide (8.3 mmol, 2.4 g) dissolved in
water (20 mL) was added. The reaction was stirred for 4 h, then
the water layer was decanted off and the remaining oil was
washed three times with water. The remaining product was
dissolved in a small amount of acetone and filtered, the filtrate
volume was reduced under high vacuum (1 mmHg) for 1 week
and the final product stored under dry nitrogen (3.1 g, 94%).
dH(DMSO): 3.66 (2H, m), 3.52 (2H, m), 3.25 (2H, m), 3.21 (2H, m),
1.62 (2H, m), 1.28 (3H, t), 0.96 (3H, t). Found: C, 27.85; H, 4.34;
N, 7.32; S, 15.74; F, 28.62. Calc. for C9H16N2O4F6S2: C, 27.41;
H, 4.09; N, 7.10; O, 16.23; S, 16.26; F, 28.90%.
N-Butyl-N-[2-(2-methoxyethoxy)ethyl]aziridinium
bis(trifluoromethanesulfonyl)imide. N-Butyl-N-[2-(2-
methoxyethoxy)ethyl]aziridinium iodide (82 mmol, 27 g) was
dissolved in distilled water (100 mL), and lithium bis
(trifluoromethanesulfonyl)imide (82 mmol, 23.5 g) dissolved in
water (20 mL) was added. The solution was vigorously stirred for
1 h, and then allowed to stand. A pale yellow phase, which
separated from the water layer, was collected and washed three
times with distilled water. The ionic liquid product was dissolved
in ethanol and passed through a plug of basic alumina and
charcoal. The liquid volume was reduced under high vacuum
(1 mmHg) for 1 week and the final product stored under dry
nitrogen (36 g, 91%). dH(CDCl3): 3.66 (4H, m), 3.48 (2H, t), 3.25
(2H, m), 3,21 (2H, t), 3.18 (2H, t), 3,01 (2H, t), 1.55 (2H, m),
1.16 (2H, m), 1.20 (3H, t), 0.91 (3H, t). Found: C, 32.82; H, 5.58;
N, 5.38; S, 13.27; F, 23.03. Calc. for C13H24N2O6F6S2: C, 32.36;
H, 5.01; N, 5.81; O, 19.90; S, 13.29; F, 23.63%.
N-Butyl-N-methylaziridinium dicyanamide. Sodium
dicyanamide (4.5 mmol, 0.4 g) dissolved in water (20 mL) was
added to a solution of silver nitrate (4.5 mmol, 0.77 g) in
water (30 mL). The white precipitate, which immediately
formed, was collected via filtration and washed with water [42].
The AgDCA precipitate was added to a solution of N-butyl-N-
methylaziridinium iodide (4.1 mmol, 1.0 g) in water (20 mL).
The mixture was stirred for 3 h at 40ꢁC, and it gradually turned
pale yellow (due to the formation of AgI). The mixture was
cooled and filtered, and the volume reduced under high vacuum.
Acetone was added to the remaining oil to precipitate any
remaining silver iodide or AgDCA (0.7 g, 92%). dH(DMSO):
3.66 (2H, m), 3.52 (2H, m), 3.25 (2H, m), 3.01 (3H, s), 1.63
(2H, m), 1.26 (2H, m), 0.92 (3H, t). Found: C, 59.26; H, 8.95;
N, 31.15. Calc. for C9H16N4: C, 59.97; H, 8.95; N, 31.08%.
N-butyl-N-ethylaziridinium dicyanamide. Sodium
dicyanamide (15.7 mmol, 1.4 g) dissolved in water (30 mL)
was added to a solution of silver nitrate (15.7 mmol, 2.7 g) in
water (30 mL). The white precipitate, which immediately formed,
was collected via filtration and washed with water. The AgDCA
precipitate was added to a solution of N-butyl-N-ethylaziridinium
iodide (14.5 mmol, 3.7 g) in water (30 mL). The mixture was
stirred for 3 h at 40ꢁC, and it gradually turned pale yellow (due
to the formation of AgI). The mixture was cooled and filtered
and the volume reduced under high vacuum. Acetone was added
to the remaining oil to precipitate any remaining silver iodide or
AgDCA (2.6 g, 93%). dH(DMSO): 3.66 (2H, m), 3.52 (2H, m),
3.25 (2H, m), 3.21 (2H, m), 3.01 (3H, s), 1.63 (2H, m), 1.26 (2H,
m), 0.92 (3H, t). Found: C, 61.45; H, 9.77; N, 28.24. Calc. for
C10H18N4: C, 61.82; H, 9.34; N, 28.84%.
REFERENCES AND NOTES
[1] Rogers, R. D.; Seddon, K. R. Ionic Liquids: Industrial Appli-
cations to Green Chemistry; ACS Symposium Series, ACS: Washington,
DC, 2002; Vol. 818.
[2] Rogers, R. D.; Seddon, K. R. Ionic Liquids as Green Solvents:
Progress and Prospects; ACS Symposium Series, ACS: Washington, DC,
2003; Vol. 856.
[3] Rogers, R. D.; Seddon, K. R.; Volkov, S. Green Industrial
Applications of Ionic Liquids; Kluwer Academic: Dordrecht, The
Netherlands, 2002.
[4] Leveque, J. M.; Cravotto, G. Chimia 2006, 60, 313.
[5] Zhang, Z. C. Adv Catal 2006, 49, 153.
[6] Muzart, J. Adv Synth Catal 2006, 348, 275.
[7] Parvulescu, V. I.; Hardacre, C. Chem Rev 2007, 107, 2615.
[8] Zhao, H.; Xia, S. Q.; Ma, P. S. J Chem Technol Biotechnol
2005, 80, 1089.
[9] Kubota, F.; Goto, M. Solvent Extr Res Dev Jpn 2006, 13, 23.
[10] Anderson, J. L.; Dixon, J. K.; Brennecke, J. F. Acc Chem Res
2007, 40, 1208.
[11] Dietz, M. L. Sep Sci Technol 2006, 41, 2047.
[12] Kubisa, P. Prog. Polym Sci 2004, 29, 3.
[13] Antonietti, M.; Kuang, D. B.; Smarsly, B.; Zhou, Y. Angew
Chem Int Ed 2004, 43, 4988.
[14] van Rantwijk, F.; Sheldon, R. A. Chem Rev 2007, 107, 2757.
[15] Swatloski, R. P.; Rogers, R. D.; Holbrey, J. D. WO Patent
029,329, 2003; Chem Abstr 2003, 138, 289216.
[16] Turner, M. B.; Spear, S. K.; Holbrey, J. D.; Rogers, R. D.
Biomacromolecules 2005, 6, 2497.
[17] Zhu, S.; Wu, Y.; Chen, Q.; Yu, Z.; Wang, C.; Jin, S.; Ding, Y.;
Wu, G. Green Chem 2006, 8, 325.
[18] Zhu, S. J Chem Technol Biotechnol 2008, 83, 777.
[19] Freemantle, M. Chem Eng News 2003, 81, 9.
[20] Sakaebe, H.; Matsumoto, H. In Electrochemical Aspects of
Ionic Liquids; Ohno, H., Ed.; Wiley: Hoboken, NJ, 2005; Chapter14.
[21] Wang, Y. X.; Nakamura, S.; Tasaki, K.; Balbuena, P. B. J Am
Chem Soc 2002, 124, 4408.
[22] Aurbach, D.; Gamolsky, K.; Markovsky, B.; Gofer, Y.;
Schmidt, M.; Heider, U. Electrochim Acta 2002, 47, 1423.
[23] Xu, W.; Angell, C.A. Science 2003, 302, 422.
[24] Welton, T. Chem Rev 1999, 99, 2071.
[25] Fuller, J.; Carlin, C. T.; Osteryoung, R. A. J Electrochem Soc
1997, 144, 3881.
[26] Sato, T.; Maruo, T.; Marukane, S.; Takagi, K. J Power Sources
2004, 138, 253.
[27] Shin, J.-H.; Henderson, W. A.; Passerini, S. Electrochem
Commun 2003, 5, 1016.
[28] Fung, Y. S.; Zhou, R. Q. J Power Sources 1999, 81–82, 891.
[29] Garcia, B.; Lavallee, S.; Perron, G.; Michot, C.; Armand, M.
Electrochim Acta 2004, 49, 4583.
[30] Sakaebe, H.; Matsumoto, H. Electrochem Commun 2003, 5,
594.
[31] Zhou, Z.-B.; Matsumoto, H.; Tatsumi, K. Chem Eur J 2006,
12, 2196.
[32] Li, X.; Zeng, Z.; Garg, S.; Twamley, B.; Shreeve, J. M. Eur J
Inorg Chem 2008, 3553.
[33] MacFarlane, D. R.; Golding, J.; Forsyth, S.; Forsyth, M.;
Deacon, G. B. Chem Commun 2001, 1430.
[34] Zhou, Z.-B.; Matsumoto, H.; Tatsumi, K. Chem Eur J 2005,
11, 752.
[35] Nakagawa, H.; Fujino, Y.; Kozono, S.; Katayama, Y.;
Nukuda, T.; Sakaebe, H.; Matsumoto, H.; Tatsumi, K. J Power Sources
2007, 174, 1021.
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

May 2012
Synthesis and Characterization of Novel Ionic Liquids: N-Substituted Aziridinium Salts
657
[36] Egashira, M.; Okada, S.; Yamaki, J.; Dri, D. A.; Bonadies, F.;
Scrosati, B. J Power Sources 2004, 138, 240.
[41] Darensbourg, D. J.; Phelps, A. L.; Le Gall, N.; Jia, L. J Am
Chem Soc 2004, 126, 13808.
[37] Zhou, Z.-B.; Takeda, M.; Ue, M. J Fluorine Chem 2003, 123, 127.
[38] Stefan, C. S.; Lemordant, D.; Biensan, P.; Siret, C.;
Claude-Montigny, B. J Therm Anal Calorim 2010, 102, 685.
[39] Kim, Y.; Ha, H.-J.; Yun, S. Y.; Lee, W. K. Chem Commun
2008, 4363.
[42] Elderfield, R. C.; Hageman, H. A. J Org Chem 1949, 14, 605.
[43] Wenker, H. J Am Chem Soc 1935, 57, 2328.
[44] Bonhote, P.; Dias, A.-P.; Papageorgiou, N.; Kalyanasundaram,
K.; Graetzel, M. Inorg Chem 1996, 35, 1168.
[45] Siqueira, L. J. A.; Ribeiro, M. C. C. J Phys Chem B 2009, 113,
1074.
[40] Sweeney, J. B. Chem Soc Rev 2002, 31, 247.
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet