S. Demir et al. / Journal of Molecular Liquids 204 (2015) 210–215
211
Fig. 1. Common cations and anions of room-temperature ionic liquids.
reference. Coupling constants (J values) are given in hertz. NMR multi-
1H NMR (300 MHz, CDCl
3
) δ (ppm) = 10.39 (s, 1H, NCHN), 7.72,
plicities are abbreviated as follows: s = singlet, d = doublet, t = triplet,
hept = heptet, and m = multiplet signal. All catalytic reactions were
monitored on an Agilent 6890N GC system by GC-FID with a HP-5 col-
umn of 30 m length, 0.32 mm diameter and 0.25 μm film thickness.
GC–MS experiments were performed on an Agilent 6890N GC system
with a 5973 N mass selective detector. Column chromatography was
performed using silica gel 60 (70–230 mesh). Solvent ratios are given
as v/v.
7.52 (s, 2H, NCHCHN), 5.44 (s, 2H, NCH
7.2 Hz, NCH CH CH CH ), 4.14 (q, 2H, J = 7.2 Hz, NCH
1.81 (pent, 2H, J = 7.5 Hz, NCH CH CH CH ), 1.29 (hex, 2H, J =
7.5 Hz, NCH CH CH CH ), 1.19 (t, 3H, J = 7.2 Hz, NCH COOCH CH ),
0.85 (t, 3H, J = 7.2 Hz, NCH ). C NMR (75 MHz, CDCl ) δ
(ppm) = 166.2 (NCH COOCH ), 138.2 (NCHN), 124.0, 121.6
(NCHCHN), 62.6 (NCH ), 50.0 (NCH COOCH CH ), 49.8
(NCH CH CH CH ), 31.9 (NCH CH CH ), 19.3 (NCH CH CH CH ),
3.9 (NCH COOCH CH CH CH CH ). Anal. Calc. for
Cl: C, 53.55; H, 7.76; N, 11.35. Found: C, 53.51; H, 7.73; N:
2
COOCH
2
CH
3
), 4.23 (t, 2H J =
2
2
2
3
2
COOCH CH ),
2
3
2
2
2
3
2
2
2
3
2
2
3
13
2
CH
2
CH
CH
CH
2
CH
3
3
2
2
3
2
COOCH
2
3
2
2
3
2
2
2
3
2
CH
2
2
3
2
2
2
3
1
C
2
2
3
), 13.3 (NCH
2
2
2
3
11 19 2 2
H N O
2
2
2
.2. Synthesis of 1,3-dialkylimidazole salts (1–6)
11.30%.
.2.1. Synthesis of 1,3-dialkylimidazolium chloride (1–2)
.2.1.1. 1-methyl-3-ethylacetylimidazolium chloride, 1a. A mixture of 1-
2.2.1.4. 1-n-Butyl-3-methoxyethoxymethylimidazolium chloride, 2b. A
mixture of 1-butylimidazole (0.10 mol) and 2-methoxyethoxymethyl
chloride (0.12 mol) was stirred in DMF (5 mL) at 70 °C for 5 h. The prod-
uct was washed with diethyl ether (3 × 30 mL) and dried under vacuum
methylimidazole (0.10 mol) and ethylchloroacetate (0.12 mol) was
stirred in DMF (5 mL) at 70 °C for 5 h. The product was washed with
diethyl ether (3 × 30 mL) and dried under vacuum at 70 °C for 8 h.
at 70 °C for 8 h. Yield: 1.72 g (69%).
1
H NMR (300 MHz, CDCl
3
) δ (ppm) = 11.10 (s, 1H, NCHN), 7.55, 7.39
OCH CH OCH ), 4.34 (t, 2H J = 7.2 Hz,
), 3.88–3.85 (m, 2H, NCH OCH CH OCH ), 3.56–3.53 (m,
CH OCH ), 3.33 (s, 3H, NCH OCH CH OCH ), 1.93 (pent,
2H, J = 7.5 Hz, NCH CH CH CH ), 1.40 (hex, 2H, J = 7.5 Hz,
NCH CH CH CH ), 0.98 (t, 3H, J = 7.2 Hz, NCH
75 MHz, CDCl ) δ (ppm) = 138.3 (NCHN), 121.9, 121.1 (NCHCHN),
OCH CH OCH ), 71.2 (NCH OCH CH OCH ), 69.8, 59.0
CH OCH ), 50.1 (NCH CH CH CH ), 32.0 (NCH CH CH CH ),
9.5 (NCH CH CH CH ), 13.4 (NCH CH CH CH ). Anal. Calc. for
Cl: C, 53.11; H, 8.51; N, 11.26. Found: C, 53.15; H, 8.54; N:
Yield: 1.69 g (83%).
1
(s, 2H, NCHCHN), 5.92 (s, 2H, NCH
NCH CH CH CH
H, NCH OCH
2
2
2
3
H NMR (300 MHz, CDCl
3
) δ (ppm) = 10.31 (s, 1H, NCHN), 7.73,
COOCH CH ), 4.15 (q, 2H, J =
), 4.02 (s, 3H, NCH ), 1.22 (t, 3H, J = 7.2 Hz,
). C NMR (75 MHz, CDCl ) δ (ppm) = 166.2
), 138.6 (NCHN), 123.9, 123.2 (NCHCHN), 62.7
), 50.1(NCH COOCH CH ), 36.7 (NCH ), 14.0
Cl: C, 46.95; H, 6.40; N,
2
2
2
3
2
2
2
3
7
7
.62 (s, 2H, NCHCHN), 5.44 (s, 2H, NCH
.2 Hz, NCH COOCH CH
COOCH
2
2
3
2
2
2
2
3
2
2
2
3
2
2
1
3
3
3
2
2
2
3
NCH
NCH
NCH
NCH
2
2
CH
3
3
13
2
2
2
3
2 2 2 3
CH CH CH ). C NMR
(
(
(
2
2
2
COOCH
COOCH
COOCH
2
CH
CH
3
(
3
2
3
2
2
3
3
7
9.1 (NCH
OCH
2
2
2
3
2
2
2
3
2
CH
3
). Anal. Calc. for C
8
H
13
N
2
O
2
(NCH
2
2
2
3
2
2
2
3
2
2
2
3
1
3.69. Found: C, 46.92; H, 6.43; N: 13.65%.
1
C
2
2
2
3
2
2
2
3
11 21 2 2
H N O
2
.2.1.2. 1-Methyl-3-methoxyethoxymethylimidazolium chloride, 1b. A
1
2
2
1.27%.
mixture of 1-methylimidazole (0.10 mol) and 2-methoxyethoxymethyl
chloride (0.12 mol) was stirred in DMF (5 mL) at 70 °C for 5 h. The prod-
uct was washed with diethyl ether (3 × 30 mL) and dried under vacuum
.2.2. Synthesis of 1,3-dialkylimidazolium tetrafluoroborate (3–4)
at 70 °C for 8 h. Yield: 1.76 g (85%).
.2.2.1. 1-Methyl-3-ethylacetylimidazolium tetrafluoroborate, 3a. 3a was
1
H NMR (300 MHz, CDCl
3
) δ (ppm) = 9.97 (s, 1H, NCHN), 7.46, 7.32
OCH CH OCH ), 3.62 (s, 3H, NCH ),
CH OCH ), 2.98 (t, 2H, J = 4.2 Hz,
), 2.78 (s, 3H, NCH
prepared using ionic liquid 1a with chloro anion at room temperature.
A mixture of chloride salt (0.10 mol) and NH BF (0.13 mol) in dichlo-
(
3
s, 2H, NCHCHN), 5.34 (s, 2H, NCH
.27 (t, 2H, J = 1.8 Hz, NCH OCH
NCH OCH CH OCH
75 MHz, CDCl
2
2
2
3
3
4
4
2
2
2
3
romethane (50 mL) was stirred at room temperature for 24 h. After fil-
tration, the solvent was removed by vacuum. The remaining viscous
liquid was then dried under vacuum at 70 °C for 8 h to give the product.
13
2
2
2
3
2
2 2 3
OCH CH OCH ). C NMR
(
6
(
3
) δ (ppm) = 137.1 (NCHN), 123.8, 121.4 (NCHCHN),
OCH CH OCH ), 58.4 (NCH OCH CH OCH ), 36.2, 36.1
CH OCH ), 30.9 (NCH ). Anal. Calc. for C Cl: C,
8.9 (NCH
OCH
2
2
2
3
2
2
2
3
Yield: 1.87 g (73%).
NCH
2
2
2
3
3
8
H
15
N
2
O
2
1
H NMR (300 MHz, D
2
O) δ (ppm) = 8.72 (s, 1H, NCHN), 7.43 (s,
COOCH CH ), 4.23 (q, 2H, J =
), 3.87 (s, 3H, NCH ), 1.23 (t, 3H, J =
). C NMR (75 MHz, CDCl ) δ (ppm) =
), 137.4 (NCHN), 123.6, 123.5 (NCHCHN),
), 49.8(NCH COOCH CH ), 35.9 (NCH ), 13.2
). Anal. Calc. for C B: C, 37.53; H, 5.12;
N, 10.94. Found: C, 37.51; H, 5.16; N: 10.92%.
4
6.49; H, 7.32; N, 13.55. Found: C, 46.51; H, 7.35; N: 13.50%.
2
3
H, NCHCHN), 5.08 (s, 2H, NCH
.6 Hz, NCH COOCH CH
COOCH CH
COOCH CH
COOCH CH
COOCH CH
2
2
3
2
2
3
3
1
3
2
.2.1.3. 1-n-Butyl-3-ethylacetylimidazolium chloride, 2a. A mixture of 1-
3.6 Hz, NCH
168.2 (NCH
63.6 (NCH
(NCH
2
2
3
3
butylimidazole (0.10 mol) and ethylchloroacetate (0.12 mol) was
stirred in DMF (5 mL) at 70 °C for 5 h. The product was washed with
diethyl ether (3 × 30 mL) and dried under vacuum at 70 °C for 8 h.
Yield: 1.70 g (69%).
2
2
3
2
2
3
2
2
3
3
2
2
3
8 13 4 2 2
H F N O
Scheme 1. Anion exchange reaction by metathesis of the halide salt with a metal or ammonium salt.