ACIDIC IONIC LIQUID
2229
7.27–7.38 (m, 4H), 8.77 (s, 1H);13C NMR (125 MHz, DMSO-d6) d 29.00, 57.48,
116.11, 116.15, 116.28, 116.32, 116.51, 119.07, 129.32, 129.38, 130.48, 130.54,
135.10, 136.79, 139.64, 140.41, 153.95, 160.31, 163.30; IR (KBr) cmꢁ1: 3415, 3220,
3123, 2987, 2918, 1681, 1603, 1507, 1455, 1352, 1229, 1157, 1076, 886, 825, 755.
Compound 4l. 1H NMR (DMSO-d6, 500 MHz) d 1.65–2.02 (m, 1H),
2.32–2.38 (m, 1H), 2.68–2.83 (m, 2H), 3.73 (s, 3H), 3.74 (s, 3H), 5.07 (s, 1H), 6.55
(s, 1H), 6.75–6.87 (m, 4H), 7.08 (s, 1H), 7.17 (d, J ¼ 8.5 Hz, 2H), 7.26 (d, J ¼ 8.7 Hz,
2H), 8.65 (s, 1H); IR (KBr) cmꢁ1: 3374, 3214, 3114, 2957, 2932, 2835, 1682, 1604,
1511, 1449, 1349, 1276, 1247, 1176, 1029, 890, 821, 755.
Compound 4m. 1H NMR (DMSO-d6, 500 MHz) d 1.94–2.02 (m, 1H), 2.27
(s, 6H), 2.31–2.39 (m, 1H), 2.73–2.82 (m, 2H), 5.08 (s, 1H), 6.57 (s, 1H), 7.11–7.25
(m, 9H), 8.70 (s, 1H); IR (KBr) cmꢁ1: 3445, 3217, 3119, 2917, 2847, 1687, 1512,
1458, 1348, 1081, 889, 808, 750.
Compound 4o. 1H NMR (DMSO-d6, 400 MHz) d 1.98–2.08 (m, 1H),
2.28–2.35 (m, 1H), 2.85–3.05 (m, 2H), 5.36 (s, 1H), 6.83 (s, 1H), 7.33 (s, 1H),
7.41–7.55 (m, 6H), 7.77–7.97 (m, 8H), 8.89 (s, 1H); 13C NMR (125 MHz, DMSO-d6)
d 29.25, 29.46, 58.60, 117.68, 119.64, 125.77, 125.82, 126.50, 126.87, 127.10, 127.23,
127.63, 128.26, 128.45, 128.71, 129.33, 132.33, 133.41, 133.73, 134.11, 136.25, 137.11,
140.72, 141.62, 154.10; IR (KBr) cmꢁ1: 3433, 3207, 3107, 2923, 2849, 1671, 1615,
1507, 1457, 1360, 1123, 901, 813, 745. Anal. calcd. for C28H22N2O: C, 83.56; H,
5.51; N, 6.96%; Found: C, 83.29; H, 5.68; N, 6.71%.
Compound 4q. 1H NMR (DMSO-d6, 500 MHz) d 1.95–2.02 (m, 1H),
2.34–2.42 (m, 1H), 2.71–2.87 (m, 2H), 5.18 (s, 1H), 6.62 (s, 1H), 7.23 (s, 1H),
7.27–7.34 (m, 4H), 7.41 (d, J ¼ 8.7 Hz, 2H), 7.45 (d, J ¼ 12.0 Hz, 2H), 8.80 (s, 1H);
IR (KBr) cmꢁ1: 3409, 3223, 3122, 2919, 2850, 1673, 1489, 1453, 1406, 1352, 1272,
1090, 1013, 887, 827, 815, 755.
Compound 4r. 1H NMR (DMSO-d6, 400 MHz) d 2.06–2.14 (m, 1H),
2.54–2.61 (m, 1H), 2.82–2.99 (m, 2H), 5.49 (s, 1H), 7.09 (s, 1H), 7.51–7.60 (m,
4H), 8.19 (d, J ¼ 8.4 Hz, 2H), 8.29 (d, J ¼ 7.6 Hz, 2H), 9.19 (s, 1H), 10.31 (s, 1H);
IR (KBr) cmꢁ1: 3387, 3202, 2923, 2848, 1667, 1587, 1518, 1475, 1340, 1181, 1110,
858, 750.
Compound 4s. 1H NMR (DMSO-d6, 400 MHz) d 2.01–2.11 (m, 1H),
2.33–2.42 (m, 1H), 2.62–2.73 (m, 2H), 3.79 (s, 6H), 5.48 (s, 1H), 6.87–7.04 (m,
5H), 7.12–7.21 (m, 2H), 7.25–7.33 (m, 2H), 8.67 (s, 1H), 10.18 (s, 1H); IR (KBr)
cmꢁ1: 3423, 3163, 2962, 2900, 2834, 1666, 1594, 1552, 1488, 1461, 1243, 1194,
1178, 1028, 873, 760.
RESULTS AND DISCUSSION
To obtain the best reaction conditions, the reaction of benzaldehyde (1 mmol,
0.106 g), cyclopentanone (1 mmol, 0.084 g), and urea (1.2 mmol, 0.072 g), was exam-
ined in the presence of 10 mol% of [TEBSA][HSO4] (0.1 mmol, 0.033 g) as catalyst in
refluxing acetonitrile. When the reaction mixture was refluxed for 3 h, undesired
products were observed. In view of the current interest in environmentally benign