Syntheses
N-(aminoformimidoyl)phenol (Hsh, I).
An ethanolic solution of salicylaldehyde (0.99 g, 8.2 mmol) was added dropwise, at room temperature and with stirring, over 1 hour to hydrazine hydrate (98 %) (2.06 g, 40.3 mmol). After the addition was complete, the mixture was stirred for 10 min, and upon cooling in ice, a whitish solid appeared, which was collected by filtration, washed with diethyl ether and dried under vacuum. Yield 0.83 g (79.8 %). Anal. Calcd. for C7H8ON2: C, 61.75; H, 6.09; N, 20.58. Found: C, 62.08; H, 6.11; N, 20.62. 1H-NMR (CDCl3): 11.07 (s, 1H, -OH), 7.87 (s, 1H, -CHN), 7.22-7.18 (m, 1H, arom H), 7.12-7.09 (m, 1H, arom H), 6.96-6.93 (m, 1H, arom H), 6.89-6.86 (m, 1H, arom H), 5.43 (s, 2H, -NH2). MS (EI) m/z (%): 136 (M+, 100). IR (KBr) ν/cm-1: 3383, 3280, 1617, 1572, 1491, 1465, 1405, 1271, 1198, 1097, 940, 898, 784, 749, 705, 642, 558. UV/Vis (DMF) λmax/nm (ε/dm3mol-1cm-1): 355 (504).
N-(aminoformimidoyl)-6-methoxyphenol (Hmsh, II).
A hydrazine hydrate solution (80 %) (2.80 g, 44.7 mmol) was added dropwise, at room temperature and with stirring, over 5 min to an ethanolic solution of 3-methoxysalicylaldehyde (4.82 g, 31.7 mmol). The resulting light yellow coloured solid was washed with diethyl ether and dried under vacuum. Yield 3.52 g (66.2 %). Anal. Calcd. for C8H10O2N2: C, 57.82; H, 6.07; N, 16.86. Found: C, 57.97; H, 5.95; N, 16.93. 1H-NMR (CDCl3): δ 11.20 (s, 1H, -OH), 7.86 (s, 1H, -CHN), 6.85-6.72 (m, 3H, arom H), 5.48 (s, 2H, -NH2), 3.90 (s, 3H, -OCH3). MS (EI) m/z (%): 166 (M+, 100). IR (KBr) ν/cm-1: 3416, 3369, 1623, 1573, 1468, 1411, 1320, 1257, 1247, 1089, 1072, 965, 928, 838, 813, 777, 731, 620. UV/Vis (DMF) λmax/nm (ε/dm3mol-1cm-1): 358 (856).
N-(aminoformimidoyl)naphthol (Hnh, III).
This compound was prepared following the procedure described for I, but adding a methanolic solution of 2-hydroxy-1-naphtlaldehyde (0.87 g, 5.1 mmol) to hydrazine hydrate (98 %) (1.29 g, 25.3 mmol). After the addition was complete, the yellow-golden solid was collected by filtration, washed with diethyl ether and dried under vacuum. Yield 0.62 g (65.9 %). Anal. Calcd for C11H10ON2: C, 70.95; H, 5.41; N, 15.04. Found: C, 70.53; H, 5.65; N, 15.22. 1H-NMR (CDCl3):
12.33 (s, 1H, -OH), 8.80 (s, 1H, -CHN), 8.00-7.97 (d, 1H, arom H), 7.78-7.71 (m, 2H, arom H), 7.51-7.46 (m, 1H, arom H), 736-7.31 (t, 1H, arom H), 7.21-7.18 (d, 1H, arom H), 5.54 (s, 2H, -NH2). MS (EI) m/z (%): 186 (M+, 100). IR (KBr) ν/cm-1: 3390, 3375, 1621, 1603, 1579, 1466, 1417, 1315, 1281, 1241, 1181, 1082, 794, 747. UV/Vis (DMF) λmax/nm (ε/dm3mol-1cm-1): 348 (9415), 361 (9353), 410 (2383), 430 (1908).
4’-Formylbenzo-15-crown-5 (IV).
This compound [
20] was prepared from the reaction of 1,11-dichloro-3,6,9-trioxaundecane (53.3 g, 180.0 mmol) with 3,4-dihydroxybenzaldehyde (25.0 g, 181.0 mmol) and NaOH (15.1 g, 377.5 mmol) in water/
n-butanol. After recrystallization from hot
n-heptane and activated charcoal, a white crystalline solid was obtained (12.44 g). Yield 23.3 %.
1H-NMR (CDCl
3): δ 9.83 (s, 1H, -CHO), 7.46-7.38 (m, 2H, arom H), 6.96-6.92 (d, 1H, arom H), 4.23-4.17 (m, 4H, -CH
2), 3.96-3.90 (m, 4H, -CH
2), 3.80-3.75 (m, 8H, -CH
2). MS (EI) m/z (%): 416 (M
+, 100).
N-(formimidoyl-benzo-15-crown-5)-N´-(formimidoyl)phenol (Hsh-b-15-c-5, V).
To an ethanolic solution of IV (0.88 g, 3.0 mmol) was added a solution of I (0.34 g, 2.5 mmol) in ethanol. The mixture was refluxed for 3 h. The resulting light yellow compound was washed with ethanol. The compound was recrystallized from methanol and dried under vacuum. Yield 0.69 g (66.6 %). Anal. Calcd for C22H26O6N2: C, 63.76; H, 6.32; N, 6.76. Found: C, 64.34; H, 6.70; N, 6.58. 1H-NMR (CDCl3): 11.85 (s, 1H, -OH), 8.75-8.73 (d, 1H, -CHN), 8.56-8.53 (d, 1H, -CHN), 7.50-7.22 (m, 4H, arom H), 7.04-6.66 (m, 3H, arom H), 4.26-4.18 (m, 4H, -CH2), 3.97-3.92 (m, 4H, -CH2), 3.71-3.68 (m, 8H, -CH2). MS (EI) m/z (%): 414 (M+, 100). IR (KBr) ν/cm-1: 2932, 2867, 1622, 1598, 1567, 1508, 1449, 1428, 1411, 1344, 1306, 1268, 1226, 1174, 1125, 1055, 1017, 986, 968, 941, 844, 813, 746. UV/Vis (DMF) λmax/nm (ε/dm3mol-1cm-1): 344 (26137), 356 (26698).
N-(formimidoyl-benzo-15-crown-5)-N´-(formimidoyl)-6-methoxyphenol (Hmsh-b-15-c-5 VI).
This compound was prepared by the procedure described for V, but using II (0.17 g, 1.0 mmol) and IV (0.37 g, 1.2 mmol). The resulting light yellow solid was washed with diethyl ether. The compound was recrystallized from methanol and dried under vacuum. Yield 0.37 g (81.6 %). Anal. Calcd for C23H28O7N2: C, 62.15; H, 6.35; N, 6.30. Found: C, 61.63; H, 6.40; N, 6.42. 1H-NMR (CDCl3): 11.81 (s, 1H, -OH), 8.75-8.71 (d, 1H, -CHN), 8.56-8.52 (d, 1H, -CHN), 7.49 (s, 1H, arom H), 7.29-7.26 (m, 1H, arom H), 7.00-6.87 (m, 4H, arom H), 4.26-4.18 (m, 4H, -CH2), 3.94-3.92 (m, 7H, -CH2, -OCH3), 3.78-3.75 (m, 8H, -CH2). MS (FAB) m/z (%): 445 ([M+H]+, 15). IR (KBr) ν/cm-1: 2930, 2874, 1623, 1601, 1577, 1511, 1464, 1436, 1310, 1266, 1131, 1095, 1078, 1052, 966, 736. UV/Vis (DMF) λmax/nm (ε/dm3mol-1cm-1): 340 (39706), 349 (38578).
N-(formimidoyl-benzo-15-crown-5)-N´-(formimidoyl)-naphthol (Hnh-b-15-c-5 VII).
This compound was prepared by a modification of the procedure described for V. To a methanolic solution of IV (0.20 g; 0. 7 mmol) was added a solution of III (0.10 g; 0.5 mmol) in methanol. The mixture was refluxed for 4.5 h. The resulting yellow solid was washed with diethyl ether, recrystallized from ethanol and dried under vacuum. Yield 0.09 g (35.9 %). Anal. Calcd for C23H28O7N2·1/2 C3H5O: C, 66.51; H, 6.41; N, 5.70. Found: C, 66.73; H, 6.15; N, 5.68. 1H-NMR ((CD3)2SO): 13.02 (s; 1H, -OH), 9.87 (d; 1H, -CHN), 8.78 (d; 1H, -CHN), 8.67-8.49 (m; 1H, arom H), 8.06-7.88 (m; 2H, arom H), 7.62-7.42 (m; 6H, arom H), 4.13-4.11 (m; 4H, -CH2), 3.81-3.80 (m; 4H, -CH2), 3.68-3.67 (m; 8H, -CH2). MS (FAB) m/z (%): 464 ([M+H]+, 84). IR (KBr) ν/cm-1: 3445, 3408, 2931, 2876, 1720, 1623, 1580, 1544, 1512, 1436, 1419, 1405, 1278, 1239, 1183, 1137, 1052, 721, 501. UV/Vis (DMF) λmax/nm (ε/dm3mol-1cm-1): 339 (27858), 371 (30539), 387 (33496), 404 (27812), 438 (4165).