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+
OH), 5.97 (s, 1H, CHCl), 8.99 (s, br, 2H, NH2 ); 13C NMR (100
MHz, DMSO-d6) d (ppm) ¼ 32.71 (CH3), 50.56 (CH2), 56.47
(CH2), 70.47 (CHCl2), 166.45 (COOꢁ).
5.2.1 Route I (preparation of ILs 1–12). Hydroxylalkyl-
amines (0.01 mol) dissolved in methanol (20 mL) was added to
a round-bottom ask equipped with a magnetic stirrer. Next,
0.011 mol of dichloroacetic acid was added dropwise and the
mixture was stirred at room temperature for 24 h. Methanol was
removed via rotary evaporation, and the desirable product was
thoroughly washed with diethyl ether and nally dried under
5.3.6 IL 6. Yield: 98%; light yellow liquid; 1H NMR (400
MHz, DMSO-d6) d (ppm) ¼ 0.87 (t, 3H, 3JH–H ¼ 8.0 Hz, CH3), 1.31
(sext, 2H, CH2), 1.57 (m, 2H, CH2), 2.85 (m, 2H, CH2), 2.94 (t, 2H,
3JH–H ¼ 4.0 Hz, C2), 3.63 (t, 2H, 3JH–H ¼ 8.0 Hz, CH2), 5.40 (s, br,
1H, OH), 5.93 (s, 1H, CHCl), 8.45 (s, br, 2H, NH2+); 13C NMR (100
MHz, DMSO-d6) d (ppm) ¼ 13.55 (CH3), 19.35 (CH2), 27.40
(CH2), 46.59 (CH2), 48.90 (CH2), 56.47 (CH2), 70.51 (CHCl2),
165.43 (COOꢁ).
ꢀ
a reduced pressure at 50 C for 24 h.
5.2.2 Route II (preparation of ILs 13–15). A total of 0.01 mol
of quaternary ammonium bromide was rst dissolved in
methanol and a stoichiometric amount of saturated methanol
solution of potassium hydroxide was added. The anion
exchange progress was monitored with the addition of an
AgNO3 solution. Upon completing the substitution of bromide
via hydroxide, no AgBr precipitation could be found. The by-
product (KBr) was precipitated and separated via ltration
through a sintered glass lter (Synthware Co., Ltd, Beijing,
China). Then, the lter (quaternary ammonium hydroxide) was
transferred to a round-bottom ask equipped with a magnetic
stirrer and was neutralized with dichloroacetic acid at a 1 : 1.1
molar ratio. The mixture was stirred at room temperature for
another 24 h. Methanol was removed via rotary evaporation,
followed by adding diethyl ether to the residue. Aer removing
the solvents by evaporation, the desirable product was obtained
5.3.7 IL 7. Yield: 93%; light yellow liquid; 1H NMR (400
MHz, DMSO-d6) d (ppm) ¼ 1.08 (dd, 6H, 3JH–H ¼ 8.0 Hz, 4.0 Hz,
CH3), 2.76 (m, 4H, CH2), 2.96 (m, 2H, CH2), 3.95 (m, 2H, CH),
5.25 (s, br, 2H, OH), 5.97 (s, 1H, CHCl), 8.63 (s, br, 2H, NH2+);
13C NMR (100 MHz, DMSO-d6) d (ppm) ¼ 21.18 (CH3), 53.68
(CH2), 62.03 (CH), 70.52 (CHCl2), 165.46 (COOꢁ).
5.3.8 IL 8. Yield: 99%; light yellow liquid; 1H NMR (400
MHz, DMSO-d6) d (ppm) ¼ 2.80 (s, 3H, CH3), 3.19 (t, 4H, 3JH–H
¼
3
8.0 Hz, CH2), 3.73 (t, 4H, JH–H ¼ 8.0 Hz, CH2), 4.23 (s, br, 2H,
OH), 6.02 (s, 1H, CCl), 9.98 (s, br, 1H, NH+); 13C NMR (100 MHz,
DMSO-d6) d (ppm) ¼ 40.56 (CH3), 55.43 (CH2), 57.49 (CH2),
70.13 (CHCl2), 166.03 (COOꢁ).
5.3.9 IL 9. Yield: 94%; light yellow liquid; 1H NMR (400
MHz, DMSO-d6) d (ppm) ¼ 1.16 (t, 6H, 3JH–H ¼ 8.0 Hz, CH3), 3.06
ꢀ
and nally dried under a reduced pressure at 50 C for 24 h.
3
3
(t, 6H, JH–H ¼ 8.0 Hz, CH2), 3.70 (t, 6H, JH–H ¼ 8.0 Hz, CH2),
5.65 (s, br, 2H, OH, NH+), 5.98 (s, 1H, CHCl2); 13C NMR (100
MHz, DMSO-d6) d (ppm) ¼ 8.84 (CH3), 46.92 (CH2), 53.18 (CH2),
5.3 Physicochemical data
5.3.1 IL 1. Yield: 98%; light yellow solid; mp: 68.0–68.8 ꢀC; 55.93 (CH2), 70.44 (CHCl2), 166.32 (COOꢁ).
1H NMR (400 MHz, DMSO-d6) d (ppm) ¼ 2.84 (t, 2H, JH–H
¼
5.3.10 IL 10. Yield: 92%; white solid; mp: 67.4 ꢀC; 1H NMR
3
8.0 Hz, CH2), 3.57 (t, 2H, JH–H ¼ 8.0 Hz, CH2), 5.30 (s, br, 1H, (400 MHz, DMSO-d6) d (ppm) ¼ 3.09 (t, 6H, 3JH–H ¼ 4.0 Hz, CH2),
3
OH), 5.91 (s, 1H, CHCl), 7.98 (s, br, 3H, NH3 ); 13C NMR (100 3.66 (t, 6H, 3JH–H ¼ 4.0 Hz, CH2), 5.26 (s, br, 3H, OH), 5.95 (s, 1H,
+
MHz, DMSO-d6) d (ppm) ¼ 41.28 (CH2), 57.65 (CH2), 70.84 CHCl); 13C NMR (100 MHz, DMSO-d6) d (ppm) ¼ 55.81 (CH2),
(CHCl2), 165.50 (COOꢁ).
56.43 (CH2), 70.70 (CHCl2), 165.63 (COOꢁ).
1
5.3.2 IL 2. Yield: 95%; white solid; mp: 109.8–110.8 ꢀC; H
5.3.11 IL 11. Yield: 90%; light yellow solid; mp: 63.8–
3
1
ꢀ
NMR (400 MHz, DMSO-d6) d (ppm) ¼ 1.08 (d, 3H, JH–H
¼
68.0 C; H NMR (400 MHz, DMSO-d6) d (ppm) ¼ 1.08 (d, 9H,
4.0 Hz, CH3), 2.60 (m, 1H, CH2), 2.82 (dd, 1H, JH–H ¼ 8.0 Hz, 3JH–H ¼ 8.0 Hz, CH3), 3.12 (m, 6H, CH2), 4.06 (m, 3H, CH), 4.68
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4.0 Hz, CH2), 3.82 (m, 1H, CH), 5.44 (s, br, 1H, OH), 5.94 (s, 1H, (s, br, 3H, OH), 6.05 (s, 1H, CHCl); 13C NMR (100 MHz, DMSO-
+
CHCl), 8.08 (s, br, 3H, NH3 ); 13C NMR (100 MHz, DMSO-d6) d6) d (ppm) ¼ 20.91 (CH3), 21.41 (CH3), 21.60 (CH3), 60.14 (CH),
d (ppm) ¼ 20.97 (CH3), 45.66 (CH2), 63.14 (CH), 70.83 (CHCl2), 60.81 (CH), 61.15(CH2), 61.83 (CH2), 69.99 (CHCl2), 165.59
165.50 (COOꢁ).
(COOꢁ).
5.3.3 IL 3. Yield: 97%; light yellow liquid; 1H NMR (400
5.3.12 IL 12. Yield: 90%; yellow liquid; 1H NMR (400 MHz,
MHz, DMSO-d6) d (ppm) ¼ 1.69 (quint, 2H, 3JH–H ¼ 8.0 Hz, CH2), DMSO-d6) d (ppm) ¼ 3.12 (s, 9H, CH3), 3.06 (t, 2H, JH–H
¼
3
3
3
2.84 (t, 2H, JH–H ¼ 8.0 Hz, CH2), 3.47 (t, 2H, JH–H ¼ 8.0 Hz, 4.0 Hz, CH2), 3.82 (m, 2H, CH2), 5.92 (s, br, 1H, OH), 5.85 (s, 1H,
CH2), 4.84 (s, br, 1H, OH), 5.90 (s, 1H, CHCl), 7.95 (s, br, 3H, CHCl); 13C NMR (100 MHz, DMSO-d6) d (ppm) ¼ 38.89 (CH3),
+
NH3 ); 13C NMR (100 MHz, DMSO-d6) d (ppm) ¼ 30.17 (CH2), 55.43 (CH2), 57.49 (CH2), 70.13 (CHCl2), 166.03 (COOꢁ).
36.64 (CH2), 57.93 (CH2), 71.00 (CHCl2), 165.09 (COOꢁ).
5.3.13 IL 13. Yield: 94%; white solid; mp: 38.9 ꢀC; 1H NMR
5.3.4 IL 4. Yield: 97%; light yellow liquid; 1H NMR (400 (400 MHz, DMSO-d6) d (ppm) ¼ 0.84 (t, 3H, 3JH–H ¼ 8.0 Hz, CH3),
MHz, DMSO-d6) d (ppm) ¼ 2.96 (t, 2H, 3JH–H ¼ 4.0 Hz, CH2), 3.45 1.23 (m, 16H, CH2), 1.66 (m, 2H, CH2), 3.08 (s, 3H, CH3), 3.39
3
3
(t, 2H, JH–H ¼ 4.0 Hz, CH2), 3.51 (t, 2H, JH–H ¼ 8.0 Hz, CH2), (m, 4H, CH2), 3.43 (m, 4H, CH2), 3.81 (m, 4H, CH2), 5.67 (s, br,
3.59 (t, 2H, 3JH–H ¼ 8.0 Hz, CH2), 5.92 (s, 1H, CHCl), 7.19 (s, br, 2H, OH), 5.83 (s, 1H, CHCl); 13C NMR (100 MHz, DMSO-d6)
3H, NH3+); 13C NMR (100 MHz, DMSO-d6) d (ppm) ¼ 38.74 d (ppm) ¼ 14.05 (CH3), 21.66 (CH2), 22.19 (CH2), 25.88 (CH2),
(CH2), 60.17 (CH2), 66.67 (CH2), 70.81 (CH2), 72.26 (CHCl2), 28.60 (CH2), 28.80 (CH2), 28.92 (CH2), 29.02 (CH2), 29.10 (CH2),
165.57 (COOꢁ).
31.38 (CH2), 49.05 (CH3), 54.83 (CH2), 58.87 (CH2), 59.92 (CH2),
5.3.5 IL 5. Yield: 96%; light yellow liquid; 1H NMR (400 62.45 (CH2), 63.25 (CH2), 71.41 (CHCl2), 164.43 (COOꢁ).
1
MHz, DMSO-d6) d (ppm) ¼ 2.54 (s, 3H, CH3), 2.95 (t, 2H, 3JH–H
¼
5.3.14 IL 14. Yield: 93%; white solid; mp: 52.3–53.6 ꢀC; H
8.0 Hz, CH2), 3.63 (t, 2H, JH–H ¼ 8.0 Hz, CH2), 5.48 (s, br, 1H, NMR (400 MHz, DMSO-d6) d (ppm) ¼ 0.85 (t, 3H, 3JH–H ¼ 8.0 Hz,
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44518 | RSC Adv., 2020, 10, 44512–44521
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