Trifluoromethanesulfonate, trifluromethylsulfonylimide, and bis(trifluoromethylsulfonyl)imide salts and ionic liquids based on 1,8-diazabicyclo[5.4.0]undec-7-ene and 1,5-diazabicyclo[ 4.3.0]non-5-ene

Article abstract of DOI:10.1134/S1070428010030140

Trifluoromethanesulfonate, trifluoromethylsulfonylimide, and bis(trifluoromethylsulfonyl)imide salts and ionic liquids were synthesized from 2,3,4,6,7,8,9,10-octahydropyrimido[1,2-a]azepine (1,8-diazabicyclo[5.4.0]undec- 7-ene) and 2,3,4,6,7,8-hexahydropyrrolo[1,2-a]pyrimidine (1,5-diazabicyclo[4.3. 0]non-5-ene). Their physicochemical properties, spectral parameters, and some chemical transformations were studied.

Full text of DOI:10.1134/S1070428010030140

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2010, Vol. 46, No. 3, pp. 383–388. © Pleiades Publishing, Ltd., 2010.
Original Russian Text © L.L. Tolstikova, A.V. Bel’skikh, B.A. Shainyan, 2010, published in Zhurnal Organicheskoi Khimii, 2010, Vol. 46, No. 3,
pp. 390–395.
Trifluoromethanesulfonate, Trifluromethylsulfonylimide,
and Bis(trifluoromethylsulfonyl)imide Salts and Ionic Liquids
Based on 1,8-Diazabicyclo[5.4.0]undec-7-ene and 1,5-Diaza-
bicyclo[4.3.0]non-5-ene
L. L. Tolstikova, A. V. Bel’skikh, and B. A. Shainyan
Favorskii Irkutsk Institute of Chemistry, Siberian Division, Russian Academy of Sciences,
ul. Favorskogo 1, Irkutsk, 664033 Russia
e-mail: bagrat@irioch.irk.ru
Received March 16, 2009
Abstract—Trifluoromethanesulfonate, trifluoromethylsulfonylimide, and bis(trifluoromethylsulfonyl)imide
salts and ionic liquids were synthesized from 2,3,4,6,7,8,9,10-octahydropyrimido[1,2-a]azepine (1,8-diaza-
bicyclo[5.4.0]undec-7-ene) and 2,3,4,6,7,8-hexahydropyrrolo[1,2-a]pyrimidine (1,5-diazabicyclo[4.3.0]non-5-
ene). Their physicochemical properties, spectral parameters, and some chemical transformations were studied.
DOI: 10.1134/S1070428010030140
2,3,4,6,7,8-hexahydropyrrolo[1,2-a]pyrimidine) and
containing trifluoromethanesulfonate, trifluoromethyl-
sulfonylimide, and bis(trifluoromethylsulfonyl)imide
anions. The initial nitrogen-containing bases, DBU and
DBN, are readily obtained from ε-caprolactam and
pyrrolidin-2-one, respectively, and their synthetic and
commercial accessibilities are quite comparable with
those of 1-alkylimidazoles that are starting compounds
for the preparation of most known ionic liquids.
First ionic liquids based on 1,8-diazabicyclo[5.4.0]-
undec-7-ene (DBU, 2,3,4,6,7,8,9,10-octahydropyrim-
ido[1,2-a]azepine) cations and various anions (Cl, Br,
OTs, OTf) were reported previously [1–3]. Of partic-
ular interest are ionic liquids containing bis(trifluoro-
methylsulfonyl)imide anion (CF3SO2)2N– which con-
siderably reduces the melting point and viscosity of
ionic liquids, as compared to other anions. In addition,
organic salts with trifluoromethylsulfonylimide and
other perfluoroalkylsulfonylimide anions are mainly
hydrophobic and are characterized by high thermal and
electrochemical stability [4–6]. First ionic liquids with
trifluoromethylsulfonylimide anion were synthesized
on the basis of imidazolium cation in 1995–96 [7, 8],
and they subsequently found wide application [9–11].
Almost similar structures of DBU (I) and DBN (II)
in salts (X = N) and ionic liquids (X = R) makes it
possible to use spectral parameters of readily obtain-
able and identifiable salts DBUH+ Y– and DBNH+ Y–
for identification of ionic liquids DBUR+ Y– and
DBNR+ Y– which are synthesized by different
methods.
In the present communication we describe the syn-
thesis of new salts and ionic liquids derived from DBU
(I) and 1,5-diazabicyclo[4.3.0]non-5-ene (II, DBN,
Trifluoromethanesulfonate, trifluoromethylsul-
fonylimide, and bis(trifluoromethylsulfonyl)imide
DBU and DBN salts Ia–Ic and IIa–IIc were prepared
in quantitative yield by mixing equimolar amounts of
the corresponding base and trifluoromethanesulfonic
acid CF3SO3H, trifluoromethanesulfonamide
CF3SO2NH2, or trifluoromethansulfonimide
(CF3SO2)2NH under solvent-free conditions or in
chloroform at room temperature. The products were
analyzed after removal of the solvent without addi-
tional purification. The isolated salts were colorless
X
N
X
N
Y–
Y–
N
N
Ia–Ig
IIa–IIf
I, II, X = H: Y = F3CSO2O (a), F3CSO2NH (b), (F3CSO2)2N
(c); X = Pr: Y = Cl (d), (F3CSO2)2N (e); X = Ph, Y =
(F3CSO2)2N (f); X = F3CSO2, Y = F3CSO2O (g).
383

TOLSTIKOVA et al.
384
viscous liquids or white low-melting crystalline solids.
The reaction of DBN with (CF3SO2)2NH under the
above conditions was strongly exothermic; therefore,
the reaction mixture was diluted with methylene
chloride or chloroform and cooled to 5–10°C.
formed in more than 90% yield (Scheme 1). Approx-
imately after 1 h, the reaction mixture turned turbid,
and after 4–6 h the product separated from the mixture
as colorless low-melting crystals. Excess propyl
chloride was distilled off under reduced pressure, and
salts Id and IId were dried in a high vacuum.
Protonation of DBU and DBN involves the imino
nitrogen atom and leads to different shifts of signals in
Chloride ion exchange in ionic liquids Id and IId
was effected by the action of lithium bis(trifluoro-
methylsulfonyl)imide in methanol according to a mod-
ified procedure, which was used previously for the
synthesis of analogous imidazole- and triazole-based
ionic liquids [14]. Following this procedure we ob-
tained 94% of 1-propyl-2,3,4,6,7,8,9,10-octahydropy-
rimido[1,2-a]azepin-1-ium bis(trifluoromethylsul-
fonyl)imide (Ie) and 1-propyl-2,3,4,6,7,8-hexahydro-
pyrrolo[1,2-a]pyrimidin-1-ium bis(trifluoromethylsul-
fonyl)imide (IIe) as yellow liquids (Scheme 1).
1
the H and 13C NMR spectra recorded from solutions
in CD3CN [12]. The 1H NMR spectra in CDCl3 consid-
erably differ from the spectra in acetonitrile-d3, especi-
ally for the free bases; therefore, protonation-induced
shifts (Δδ) are much greater. The Δδ values in CDCl3
and CD3CN (in parentheses; data of [12]) are given
below. Shifts of signals in the 13C NMR spectra are
weakly sensitive to the solvent nature.
1.0 (0.08)
1.05 (0.11)
0.47 (0.18)
7
9
8
0.76 (0.47)
1.28 (0.32)
10
1.10 (0.12)
8
It might be expected that DBU as a strong base
should be capable of reacting with trifluoromethane-
sulfonic anhydride to give 1-(trifluoromethylsulfonyl)-
2,3,4,6,7,8,9,10-octahydropyrimido[1,2-a]azepin-1-
ium trifluoromethanesulfonate (Ig) (Scheme 2).
7
6
8a
10a
0.60 (0.31)
6
1N
1.30 (0.27)
N5 1N
N5
2
4
2
4
1.12 (0.12)
0.48 (0.12)
0.39 (0.18)
1.20 (0.20)
3
3
1.20 (0.21)
0.50 (0.27)
Trifloromethylsulfonylimide ionic liquids based on
DBU and DBN cations can be synthesized either by
direct quaternization of the corresponding bases with
N-alkyl(or aryl)trifluoromethanesulfonimide
(CF3SO2)2NR or via anion exchange in preliminarily
prepared chloride ionic liquids by the action of lithium
bis(trifluoromethylsulfonyl)imide. Compounds I and
II smoothly reacted with propyl chloride on heating
with 3 equiv of the chloroalkane at the boiling point
according to the procedure described in [13], and the
corresponding quaternary ammonium salts were
Scheme 2.
SO2CF3
N
N
(F3CSO2)2O
CF3SO2
N
N
Ig
In fact, DBU smoothly reacted with an equimolar
amount of (CF3SO2)2O in chloroform at room tempera-
ture without appreciable heat evolution; the reaction
mixture turned bright yellow in ~3 min. After removal
of the solvent, the residue was analyzed by H, 13C,
1
Scheme 1.
and 19F NMR spectroscopy. The results showed the
presence of two compounds, Ia and Ig at a ratio of
58.8:41.2. The formation of 2,3,4,6,7,8,9,10-octahy-
dropyrimido[1,2-a]azepin-1-ium trifluoromethane-
sulfonate (Ia) followed from complete coincidence of
C3H7
N
C3H7Cl
( )n
Cl–
N
1
the major set of signals in the H, 13C, and 19F NMR
Id, IId
N
spectra of the product mixture with that observed in
the spectra of salt Ia prepared independently (includ-
(F3CSO2)2NLi
( )n
N
1
ing the NH signal). The minor set of signals in the H
I, II
R
and 13C NMR spectra was analogous to the major one:
1
N
the H NMR spectrum contained signals from eight
(F3CSO2)2NPh
( )n
(F3CSO2)2N–
CH2 groups in 2,3,4,6,7,8,9,10-octahydropyrimido-
[1,2-a]azepinium ion and no NH signal, whereas in the
13C NMR spectrum we observed additional signals as-
signable to CF3 and C=N fragments, whose intensity
N
Ie, If, IIe, IIf
R = C3H7 (e), Ph (f); I, n = 3; II, n = 1.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 46 No. 3 2010

TRIFLUOROMETHANESULFONATE, TRIFLUROMETHYLSULFONYLIMIDE, ...
385
Solubilities of ionic liquids Ia–Ic, Ie, If, IIa–IIc, IIe, and IIf in water and organic solvents
a
Compound no.
H2O
MeCN
EtOH Acetone CH2Cl2 CHCl3
Et2O
C6H6
Dioxane C6H14
Ia
+
+
–
–
–
+
+
–
–
–
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
–
–
–
–
–
–
–
–
+
–
–
–
–
–
–
–
+
+
+
–
–
–
+
+
+
–
+
–
–
–
–
–
–
–
–
+
–
b
b
Ib
Ic
+
+
+
+
+
+
+
+
Ie
If
IIa
IIb
IIc
IIe
IIf
b
b
b
b
+
–
–
–
b
b
b
b
+
+
a
The same for petroleum ether.
Poorly soluble.
b
strong tarring. By thorough washing of the crude prod-
ucts with diethyl ether we isolated target 1-phenyl-
2,3,4,6,7,8,9,10-octahydropyrimido[1,2-a]azepin-1-
ium bis(trifluoromethylsulfonyl)imide (If) and 1-phen-
yl-2,3,4,6,7,8-hexahydropyrrolo[1,2-a]pyrimidin-1-
ium bis(trifluoromethylsulfonyl)imide (IIf). Phenyl
group transfer from molecule III to the nitrogen atom
in bases I and II follows from the sharp difference
was lower than in the spectrum of salt Ia. All minor
signals appeared in a weaker field relative to the
corresponding signals of salt Ia. An independent
evidence in favor of formation of compound Ig is
the intensity ratio of the signals at δF –78.54 and
–74.04 ppm in the 19F NMR spectrum (70.5:29.5).
Taking into account that the signal at δF –78.54 ppm
belongs to trifluoromethanesulfonate anion present in
both compounds Ia and Ig, the true ratio of compounds
Ia and Ig was calculated on the basis of the 19F NMR
spectrum as (70.5 – 29.5) : 29.5 = 41 : 29.5 (or 58.2:
41.8) which completely coincides with that calculated
1
between the H NMR spectral pattern in the aromatic
region of compounds If and IIf, on the one hand, and
N-phenyl imide III, on the other. The p-H signal in the
spectrum of III is the most downfield (δ 7.60 ppm),
whereas analogous signals in the spectra of If and IIf
appear in the strongest field (δ ~6.9 ppm). The o-H and
m-H signals shift from δ 7.42 and 7.53 ppm, respec-
tively, to δ ~7.1 ppm. The upfield shift of aromatic
proton signals in going from compound III to If and
IIf is consistent with the character of variation of sub-
stituent in the benzene ring from (CF3SO2)2N to C=N+.
The 13C NMR spectra of these compounds also
displayed a large upfield shift of the Cp signal
(ΔδC >10 ppm) and even larger downfield shift of the
Ci signal (ΔδC >13 ppm) in going from compound III
to salts If and IIf.
1
from the H NMR spectrum. In addition, the minor
CF3 quartet in the 13C NMR spectrum is characterized
1
by a coupling constant JCF of 322.9 Hz, which is
larger by 3.3 Hz than the 1JCF value for the CF3 quartet
belonging to CF3SO3– ion. The observed difference is
typical of covalently bonded and anionic trifluoro-
methanesulfonate species [15]. The downfield shift of
1
signals in the H NMR spectrum of salt Ig relative to
Ia (see above) is the stronger, the closer is the corre-
sponding group to the charged [NCN]+ fragment: Δδ =
0.1 ppm for 7-H, 8-H, and 9-H, 0.3 ppm for 3-H, and
0.5–0.6 ppm for 2-H, 4-H, 6-H, and 10-H. Analogous
pattern is observed in the 13C NMR spectra, in keeping
with conjugated structure of the cation in salt Ig.
Although ionic liquids If and IIf were isolated as in-
dividual substances (according to the NMR data, they
were dark brown viscous liquids. Therefore, the reac-
tion of N-phenyltrifluoromethanesulfonimide (III)
with DBU and DBN cannot be recommended as a pre-
parative method for their synthesis.
We also tried to obtain DBU and DBN bis(tri-
fluoromethylsulfonyl)imide ionic liquids directly in
one step by reaction of the corresponding bases with
N-phenyltrifluoromethanesulfonimide (CF3SO2)2NPh
(III) which was prepared according to the procedure
described in [16]. The reaction in chloroform or meth-
ylene chloride was accompanied by heat evolution and
The solubilities of compounds Ia–Ic, Ie, If, IIa–
IIc, IIe, and IIf in water and various organic solvents
are collected in table. These data confirm hydrophobic
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 46 No. 3 2010

TOLSTIKOVA et al.
386
character of bis(trifluoromethylsulfonyl)imide salts,
unlike trifluoromethanesulfonate and trifluoromethyl-
sulfonylimide analogs. All salts are soluble in polar
organic solvents (acetonitrile, ethanol, acetone, meth-
ylene chloride) and in chloroform (due to hydrogen
bonding) and insoluble in diethyl ether and hydro-
carbons.
Colorless viscous liquid, nD22 = 1.3472, d424
=
1.66 g/cm3. IR spectrum, ν, cm–1: 3280, 2805, 1650,
1
1600, 1320, 1280, 1180, 980, 610. H NMR spectrum
(CCl3–CD3CN), δ, ppm: 1.53 m (2H, 9-H), 1.59 m (4H,
7-H, 8-H), 1.85 quint (2H, 3-H, J = 5.9 Hz), 2.59 m
(2H, 10-H), 3.19 t (2H, 2-H, J = 5.8 Hz), 3.30 t (2H,
6-H, J = 6.0 Hz), 3.30 m (2H, 4-H), 4.10 very broad s
(2H, NH). 13C NMR spectrum (CCl3–CD3CN), δC,
ppm: 19.16 (C3), 23.59 (C9), 26.36 (C7), 28.56 (C8),
31.92 (C10), 37.69 (C2), 48.20 (C4), 53.89 (C6),
121.59 q (CF3, J = 325.4 Hz), 165.53 (C=N). 19F NMR
spectrum: δF –79.99 ppm. Found, %: C 39.54; H 5.98;
F 20.02; N 14.12; S 10.59. C10H18F3N3O2S. Calculated,
%: C 39.86; H 6.02; F 18.91; N 13.94; S 10.64.
EXPERIMENTAL
The IR spectra were recorded on a Specord 75IR
spectrometer from thin films (neat) or KBr pellets. The
1H, 13C, and 19F NMR spectra were measured on
a Bruker DPX-400 instrument at 400 (1H), 100 (13C),
or 376 MHz (19F) using CDCl3 as solvent unless other-
wise stated. The chemical shifts were determined rela-
tive to tetramethylsilane (1H, 13C) or trichlorofluoro-
methane (19F).
Reactions of DBU (I) and DBN (II) with tri-
fluoromethansulfonic acid, trifluoromethanesulfon-
amide, and trifluoromethanesulfonimide (general
procedure). Compound I or II, was added at room
temperature to an equimolar amount of trifluoro-
methanesulfonic acid, trifluoromethanesulfonamide, or
trifluoromethanesulfonimide, and the mixture was
stirred for 30–60 min at room temperature. The reac-
tions of I and II with trifluoromethanesulfonic acid
were carried out in chloroform at room temperature,
and the reaction of II with (CF3SO2)2NH was carried
out in chloroform on cooling to 5–10°C.
1H-2,3,4,6,7,8,9,10-Octahydropyrimido[1,2-a]-
azepin-1-ium bis(trifluoromethylsulfonyl)imide (Ic).
Colorless viscous liquid, nD22 = 1.4516, or colorless
crystals, mp 28°C. IR spectrum, ν, cm–1: 3360, 2940,
2870, 1640, 1580, 1440, 1350, 1315, 1190, 1120,
1
1050, 600. H NMR spectrum, δ, ppm: 1.74 m (6H,
7-H, 8-H, 9-H), 2.04 quint (2H, 3-H, J = 5.9 Hz),
2.65 m (2H, 10-H), 3.37 m (2H, 2-H), 3.51 t (2H, 6-H,
J = 5.9 Hz), 3.55 m (2H, 4-H), 7.69 s (1H, NH).
13C NMR spectrum, δC, ppm: 19.06 (C3), 23.47 (C9),
26.21 (C7), 28.66 (C8), 33.18 (C10), 38.40 (C2), 48.56
(C4), 54.71 (C6), 119.57 q (CF3, J = 320.5 Hz), 166.28
(C=N). 19F NMR spectrum: δF –78.89 ppm. Found, %:
C 30.41; H 3.68; N 9.68; S 15.57. C11H17F6N3O4S2.
Calculated, %: C 30.48; H 3.95; N 9.70; S 14.80.
1H-2,3,4,6,7,8-Hexahydropyrrolo[1,2-a]pyrimi-
din-1-ium trifluoromethanesulfonate (IIa) was
synthesized as described above for compound Ia. Yield
98%, mp 52°C. IR spectrum, ν, cm–1: 3240, 3150,
2985, 1670, 1595, 1280, 1240, 1140, 1020, 620.
1H NMR spectrum, δ, ppm: 2.08 quint (2H, 3-H, J =
5.8 Hz), 2.19 quint (2H, 7-H, J = 7.6 Hz), 2.98 t (2H,
8-H, J = 7.9 Hz), 3.46 m (4H, 2-H, 4-H), 3.72 t (2H,
6-H, J = 7.2 Hz), 8.96 s (1H, NH). 13C NMR spectrum,
δC, ppm: 18.50 (C3, C7), 30.20 (C8), 38.22 (C2), 42.45
(C4), 53.69 (C6), 120.44 q (CF3, J = 319.6 Hz), 164.78
(C=N). 19F NMR spectrum: δF –79.91 ppm. Found, %:
C 35.82; H 4.67; F 21.30; N 10.02; S 11.30.
C8H13F3N2O3S. Calculated, %: C 35.03; H 4.78;
F 20.78; N 10.21; S 11.69.
1H-2,3,4,6,7,8,9,10-Octahydropyrimido[1,2-a]-
azepin-1-ium trifluoromethanesulfonate (Ia). Tri-
fluoromethanesulfonic acid, 0.45 g (3.0 mmol), was
added at room temperature to a solution of 0.46 g
(3.0 mmol) of DBU (I) in 3 ml of chloroform, and the
mixture was stirred for 2 h and left overnight. Removal
of the solvent gave 0.907 g (100%) of salt Ia as
a colorless viscous liquid, nD22 = 1.4624, d424
=
1.16 g/cm3. IR spectrum, ν, cm–1: 3290, 3150, 2930,
1640, 1580, 1440, 1310, 1240, 1140, 1020, 620.
1H NMR spectrum, δ, ppm: 1.74 m (6H, 7-H, 8-H,
9-H), 2.04 quint (2H, 3-H, J = 5.9 Hz), 2.70 m (2H,
10-H), 3.38 m (2H, 2-H), 3.54 m (4H, 4-H, 6-H),
8.84 s (1H, NH). 13C NMR spectrum, δC, ppm: 19.21
(C3), 23.67 (C9), 26.41 (C7), 28.76 (C8), 32.83 (C10),
38.21 (C2), 48.57 (C4), 54.58 (C6), 120.39 q (CF3, J =
319.5 Hz), 166.23 (C=N). 19F NMR spectrum:
δF –78.54 ppm. Found, %: C 39.10; H 5.10; F 18.88;
N 9.11; S 10.87. C10H17F3N2O3S. Calculated, %:
C 39.73; H 5.67; F 18.85; N 9.27; S 10.61.
1H-2,3,4,6,7,8-Hexahydropyrrolo[1,2-a]pyrimi-
din-1-ium trifluoromethylsulfonylimide (IIb).
mp 63–64°C. IR spectrum, ν, cm–1: 3290, 2800, 1670,
1
1595, 1380, 1290, 1170, 980, 600. H NMR spectrum
(CCl3–CD3CN), δ, ppm: 1.83 quint (2H, 3-H, J =
5.8 Hz), 1.96 quint (2H, 7-H, J = 7.7 Hz), 2.74 t (2H,
8-H, J = 7.9 Hz), 3.19 t (4H, 2-H, J = 5.8 Hz), 3.21 t
1H-2,3,4,6,7,8,9,10-Octahydropyrimido[1,2-a]-
azepin-1-ium trifluoromethylsulfonylimide (Ib).
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 46 No. 3 2010

TRIFLUOROMETHANESULFONATE, TRIFLUROMETHYLSULFONYLIMIDE, ...
387
(2H, 4-H, J = 5.8 Hz), 3.45 t (2H, 6-H, J = 7.2 Hz),
5.92 very broad s (2H, NH). 13C NMR spectrum
(CCl3–CD3CN), δC, ppm: 17.93 (C3), 18.02 (C7), 29.21
(C8), 37.25 (C2), 41.81 (C4), 52.67 (C6), 121.09 q (CF3,
J = 325.2 Hz), 163.71 (C=N). 19F NMR spectrum
(CCl3–CD3CN): δF –79.84 ppm. Found, %: C 34.72;
H 4.86; F 21.28; N 14.97; S 11.93. C8H14F3N3O2S.
Calculated, %: C 35.16; H 5.16; F 20.86; N 15.38;
S 11.73.
ppm: 0.94 t (3H, CH3, J = 7.5 Hz), 1.63 t.q (2H,
MeCH2, J = 7.5 Hz), 1.72 m (6H, 7-H, 8-H, 9-H),
2.08 quint (2H, 3-H, J = 5.9 Hz), 2.76 m (2H, 10-H),
3.40 m (2H, 2-H), 3.47 t (2H, 1-CH2, J = 5.9 Hz), 3.51 t
(2H, 4-H, J = 6.0 Hz), 3.59 m (2H, 6-H). 13C NMR
spectrum, δC, ppm: 10.64 (CH3), 19.70 (C3), 21.65
(MeCH2), 22.80 (C9), 25.73 (C7), 28.06 (C8), 28.33
(1-CH2), 46.95 (C10), 48.94 (C2), 55.08 (C4), 55.45
(C6), 119.73 q (CF3, J = 321.5 Hz), 166.33 (C=N).
19F NMR spectrum: δF –78.93 ppm. Found, %: C 35.18;
H 4.88; F 24.21; N 8.42; S 14.08. C14H23F6N3O4S2.Cal-
culated, %: C 35.36; H 4.88; F 23.97; N 8.84; S 13.49.
1H-2,3,4,6,7,8-Hexahydropyrrolo[1,2-a]pyrimi-
din-1-ium bis(trifluoromethylsulfonyl)imide (IIc).
mp 52–53°C. IR spectrum, ν, cm–1: 3380, 1680, 1590,
1
1350, 1180, 1130, 1045, 600. H NMR spectrum, δ,
1-Propyl-2,3,4,6,7,8-hexahydropyrrolo[1,2-a]-
pyrimidin-1-ium chloride (IId). A mixture of 0.61 g
(4.91 mmol) of 2,3,4,6,7,8-hexahydropyrrolo[1,2-a]-
pyrimidine and 1.17 g (14.7 mmol) of propyl chloride
was heated for 9 h under reflux, and excess propyl
chloride was evaporated. Yield 0.92 g (92%), white
crystals; the melting point was not determined, for the
product was very hygroscopic, and it quickly flowed
ppm: 2.09 quint (2H, 3-H, J = 5.8 Hz), 2.21 quint (2H,
7-H, J = 7.7 Hz), 2.97 t (2H, 8-H, J = 7.9 Hz), 3.46 t
(4H, 2-H, 4-H, J = 5.6 Hz), 3.73 t (2H, 6-H, J =
7.2 Hz), 8.07 s (1H, NH). 13C NMR spectrum, δC,
ppm: 18.51 (C3), 18.53 (C7), 30.38 (C8), 38.57 (C2),
42.63 (C4), 53.97 (C6), 119.83 q (CF3, J = 321.3 Hz),
164.96 (C=N). 19F NMR spectrum: δF –78.96 ppm.
Found, %: C 26.59; H 3.31; N 10.41; S 15.89.
C9H13F6N3O4S2. Calculated, %: S 26.67; H 3.23;
N 10.37; S 15.82.
1
on exposure to air. H NMR spectrum, δ, ppm: 0.77 t
(3H, CH3, J = 7.4 Hz), 1.53 m (2H, MeCH2, J =
7.4 Hz), 2.03 quint (2H, 3-H, J = 5.8 Hz), 2.08 quint
(2H, 7-H, J = 7.7 Hz), 2.99 t (2H, 8-H, J = 7.9 Hz),
3.26 t (2H, 2-H, J = 7.6 Hz), 3.37 t (2H, 4-H, J =
5.8 Hz), 3.42 t (2H, 6-H, J = 5.9 Hz), 3.70 t (2H,
1-CH2, J = 7.3 Hz). 13C NMR spectrum, δC, ppm:
10.63 (CH3), 17.94 (C3), 18.74 (MeCH2), 20.44 (C7),
30.50 (C8), 42.25 (C2), 44.26 (C4), 54.08 (C6), 54.62
(1-CH2), 164.06 (C=N). Found, %: C 58.73; H 9.75;
Cl 17.38; N 13.61. C10H19ClN2. Calculated, %:
C 59.25; H 9.45; Cl 17.49; N 13.82.
1-Propyl-2,3,4,6,7,8,9,10-octahydropyrimido-
[1,2-a]azepin-1-ium chloride (Id). A mixture of
0.66 g (4.34 mmol) of DBU and 1.02 g (13.0 mmol) of
propyl chloride was heated for 9 h under reflux, and
excess propyl chloride was evaporated. Yield 1.96 g
1
(95%), mp 86°C. H NMR spectrum, δ, ppm: 0.68 t
(3H, CH3, J = 7.3 Hz), 1.39 m (2H, MeCH2), 1.48 m
(6H, 7-H, 8-H, 9-H), 1.89 quint (2H, 3-H, J = 5.9 Hz),
2.66 m (2H, 10-H), 3.26 m (2H, 2-H), 3.35 m (2H,
1-CH2), 3.40 t (2H, 6-H, J = 5.5 Hz), 3.49 m (2H,
4-H). 13C NMR spectrum, δC, ppm: 10.32 (CH3), 19.50
(C3), 21.34 (MeCH2), 22.60 (C9), 25.40 (C7), 27.66
(C8), 27.70 (1-CH2), 46.72 (C10), 48.67 (C2), 54.59
(C4 ), 54.91 (C6), 165.77 (C=N). Found, %: C 62.43;
H 9.61; Cl 15.31; N 12.21. C12H23ClN2. Calculated, %:
C 62.45; H 10.05; Cl 15.36; N 12.14.
1-Propyl-2,3,4,6,7,8-hexahydropyrrolo[1,2-a]-
pyrimidin-1-ium bis(trifluoromethylsulfonyl)imide
(IIe). Dry lithium bis(tromethylsulfonyl)imide, 1.13 g
(4.0 mmol), was added to a solution of 0.81 g
(4.0 mmol) of salt IId in 10 ml of chloroform, and the
mixture was stirred for 2 h and left overnight. The
mixture was evaporated, the residue was treated with
methylene chloride, the precipitate of lithium chloride
was filtered off, and the filtrate was evaporated. Yield
1.68 g (95%), yellow liquid, nD23 = 1.4490. IR spec-
trum, ν, cm–1: 3360, 2960, 2920, 2880, 1650, 1515,
1440, 1340, 1170, 1110, 1030, 590. 1H NMR spectrum,
δ, ppm: 0.91 t (3H, CH3, J = 7.4 Hz), 1.65 t.q (2H,
MeCH2, J = 7.5 Hz), 2.10 quint (2H, 3-H, J = 6.0 Hz),
2.17 quint (2H, 7-H, J = 7.7 Hz), 2.97 t (2H, 8-H, J =
7.9 Hz), 3.30 t (2H, 1-CH2, J = 7.7 Hz), 3.39 t (4H,
2-H, 4-H, J = 5.9 Hz), 3.72 (2H, 6-H, J = 7.4 Hz).
13C NMR spectrum, δC, ppm: 10.65 (CH3), 17.75 (C3),
18.60 (MeCH2), 20.46 (C7), 30.17 (C8), 42.09 (C2),
1-Propyl-2,3,4,6,7,8,9,10-octahydropyrimido-
[1,2-a]azepin-1-ium bis(trifluoromethylsulfonyl)-
imide (Ie). Dry lithium bis(tromethylsulfonyl)imide,
1.43 g (5.0 mmol), was added to a solution of 1.15 g
(5.0 mmol) of salt Id in 12 ml of methanol, and the
mixture was stirred for 2 h and left overnight. The
mixture was evaporated, methylene chloride was
added to the residue, the precipitate of lithium chloride
was filtered off, and the filtrate was evaporated. Yield
2.22 g (94%), yellow liquid, d424 = 1.33 g/cm3, nD22
=
1.4548. IR spectrum, ν, cm–1: 3360, 2940, 1610, 1520,
1
1340, 1190, 1120, 1040, 600. H NMR spectrum, δ,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 46 No. 3 2010

TOLSTIKOVA et al.
388
44.20 (C4), 54.09 (C6), 54.72 (1-CH2), 164.15 (C=N).
19F NMR spectrum: δF –80.35 ppm. Found, %: C 32.95;
H 4.45; F 25.95; N 9.75; S 13.87. C12H19F6N3O4S2. Cal-
culated, %: C 32.21; H 4.28; F 25.48; N 9.39; S 14.33.
4.13 m (2H, 6-H). 13C NMR spectrum, δ-C, ppm: 21.00
(C3), 21.56 (C9), 23.38 (C7), 27.90 (C8), 33.50 (C10),
46.75 (C2), 52.74 (C4), 58.86 (C6), 118.48 q (CF3,
J = 322.9 Hz), 171.75 (C=N). 19F NMR spectrum:
δF –74.04 ppm.
Reactions of DBU and DBN with N-phenyltri-
fluoromethanesulfonimide (general procedure).
N-Phenyltrifluoromethanesulfonimide (III), 1.50 g
(4.2 mmol), was dissolved in 5 ml of chloroform or
methylene chloride, an equimolar amount of DBU or
DBN was added at room temperature, and the mixture
was stirred for 2 h, left overnight, and evaporated.
This study was performed under financial support
by the Russian Foundation for Basic Research (project
no. 07-03-00425).
REFERENCES
1. Kitazume, T., Zulfiqar, F., and Tanaka, G., Green Chem.,
1-Phenyl-2,3,4,6,7,8,9,10-octahydropyrimido-
2000, vol. 2, p. 133.
[1,2-a]azepin-1-ium bis(trifluoromethylsulfonyl)-
1
2. Zulfiqar, F. and Kitazume, T., Green Chem., 2000,
imide (If). H NMR spectrum, δ, ppm: 1.59 m (4H,
vol. 2, p. 137.
8-H, 9-H), 1.65 (2H, 7-H), 1.90 quint (2H, 3-H, J =
5.7 Hz), 2.62 m (2H, 10-H), 3.27 t (2H, 2-H, J =
5.6 Hz), 3.36 t (2H, 4-H, J = 5.7 Hz), 3.39 m (2H,
6-H), 6.85 t (1H, p-H, J = 7.1 Hz), 7.04 d (2H, o-H, J =
3. Tolstikova, L.L. and Shainyan, B.A., Russ. J. Org.
Chem., 2006, vol. 42, p. 1068.
4. Pringle, J.M., Golding, J., Baranyai, K., Forsyth, C.M.,
Deacon, G.B., Scott, J.L., and MacFarlane, D.R., New J.
Chem., 2003, vol. 27, p. 1504.
13
8.1 Hz), 7.12 t (2H, m-H, J = 7.5 Hz). C NMR spec-
trum, δC, ppm: 19.30 (C3), 23.72 (C9), 26.53 (C7),
28.78 (C8), 32.38 (C10), 38.08 (C2 ), 48.45 (C4), 54.28
(C6), 121.18 q (CF3, J = 319.9 Hz), 121.45 (Cp),
123.95 (Co), 128.42 (Cm), 145.36 (Ci) 165.40 (C=N).
19F NMR spectrum: δF –76.26 ppm.
5. McFarlane, D.R., Sun, J., Golding, J., Meakin, P., and
Forsyth, M., Electrochim. Acta, 2000, vol. 45, p. 1271.
6. Quek, S.K., Lyapkalo, I.M., and Huynh, H.V., Tetra-
hedron, 2006, vol. 62, p. 3137.
7. Koch, V.R., Nanjundiah, C., Battista Appetecchi, G., and
Scrosati, B., J. Electrochem. Soc., 1995, vol. 142,
p. L116.
1-Phenyl-2,3,4,6,7,8-hexahydropyrrolo[1,2-a]-
pyrimidin-1-ium bis(trifluoromethylsulfonyl)imide
1
(IIf). H NMR spectrum, δ, ppm: 1.98 quint (2H, 3-H,
8. Bonhôte, P., Dias, A., Papageorgiou, N., Kalyanasun-
daram, K., and Grätzel, M., Inorg. Chem., 1996, vol. 35,
p. 1168.
J = 5.8 Hz), 2.09 quint (2H, 7-H, J = 7.4 Hz), 2.90 t
(2H, 8-H, J = 7.7 Hz), 3.36 m (4H, 2-H, 4-H), 3.59 t
(2H, 6-H, J = 7.2 Hz), 6.91 t (1H, p-H, J = 6.9 Hz),
7.10 d (2H, o-H, J = 7.7 Hz), 7.16 t (2H, m-H, J =
7.6 Hz). 13C NMR spectrum, δC, ppm: 18.49 (C3),
18.53 (C7), 29.96 (C8), 38.07 (C2), 42.38 (C4), 53.34
(C6), 119.73 q (CF3, J = 318.0 Hz), 121.65 (Cp),
123.89 (Co), 128.51 (Cm), 145.16 (Ci), 164.39 (C=N).
19F NMR spectrum: δF –76.22 ppm.
9. Klingshirn, M.A., Broker, G.A., Holbrey, J.D.,
Shaughnessy, K.H., and Rogers, R.D., Chem. Commun.,
2002, p. 1394.
10. Bradley, A., Cogan, C.J., Hanson, B.C., Lewin, R.G.,
Ogden, M.D., Owens, S.L., Pitner, W.R., Rooney, D.W.,
Sanders, D., Smart, N.G., Taylor, R., Richard, J., and
Thied, R.C., WO Patent Appl. no. 0266712, 2002.
11. Francio, G., Solinas, M., Janssen, E., Leitner, W., Boes-
mann, A., Wasserscheid, P., Zimmermann, J., Ballivet-
Tkatchenko, D., Picquet, M., and Stutzmann, S., WO
Patent Appl. no. 0292204, 2002.
Reaction of DBU with trifluoromethanesulfonic
anhydride. A solution of 0.46 g (3.0 mmol) of DBU in
1 ml of chloroform was added at 10°C to a solution of
0.85 g (3.0 mmol) of trifluoromethanesulfonic anhy-
dride in 10 ml of chloroform, and the mixture was
stirred for 5 h at room temperature and left overnight.
Evaporation of the solvent gave 1.11 g of yellow liquid
which contained (according to the NMR data) 59% of
salt Ia and 41% of salt Ig.
12. Wiench, J.W., Stefaniak, L., Grech, E., and Bed-
narek, E., J. Chem. Soc., Perkin Trans. 2, 1999, p. 885.
13. Wilkes, J.S., Levisky, J.A., Wilson, R.A., and
Hyssey, C.L., Inorg. Chem., 1982, vol. 21, p. 1263.
14. Jin, C.-M., Twamley, B., and Shreeve, J.M., Organo-
metallics, 2005, vol. 24, p. 3020.
1-(Trifluoromethylsulfonyl)-2,3,4,6,7,8,9,10-octa-
hydropyrimido[1,2-a]azepin-1-ium trifluorometh-
anesulfonate (Ig). 1H NMR spectrum, δ, ppm: 1.83 m
(6H, 7-H, 8-H, 9-H), 2.34 m (2H, 3-H), 3.24 m (2H,
10-H), 3.95 t (2H, 2-H, J = 5.9 Hz), 4.03 m (2H, 4-H),
15. Shainyan, B.A., Tolstikova, L.L., and Zhnikin, A.R.,
Russ. J. Org. Chem., 2003, vol. 39, p. 1180.
16. Hendrickson, J.B., Bair, K.W., Bergeron, R., Giga, A.,
Skipper, P.L., Sternbach, D.D., and Wareing, J.A., Org.
Prep. Proced. Int., 1977, vol. 9, p. 173.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 46 No. 3 2010