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J. Saczewski et al.
Arch. Pharm. Chem. Life Sci. 2012, 345, 33–42
O-Benzyl-N-(2,6-dichlorobenzyl)-N-(4,5-dihydro-1H-
O-Benzyl-N-(4,5-dihydro-1H-imidazol-2-yl)-N-
imidazol-2-yl)hydroxylamine 2c
(naphthalen-1-ylmethyl)hydroxylamine 2i
M.p.: 140–1448C; 1H-NMR (500 MHz, CDCl3) d 3.40–3.49 (2H, m,
CH2), 3.85–3.94 (2H, m, CH2), 4.33 (2H, s, CH2), 4.59 (1H, bs, NH),
5.01 (2H, s, CH2), 7.13–7.17 (2H, m, CH), 7.26 (1H, t, J ¼ 7.8 Hz,
CH), 7.30–7.34 (3H, m, CH), 7.40 (2H, d, J ¼ 7.8 Hz, CH); 13C-NMR
(125 MHz, CDCl3) d 45.0, 52.6, 79.1, 128.7, 128.8, 128.9, 129.5,
130.0, 132.3, 135.2, 137.8, 167.3; IR (KBr, cmꢃ1) 3155, 2981, 2922,
2856, 1604, 1562, 1491, 1459, 1437, 1279, 1091, 1003, 991, 780,
754, 692.
Obtained as an oil, 1H-NMR (500 MHz, CDCl3) d 3.71 (4H, bs, CH2),
4.13 (2H, s, CH2), 5.16 (2H, s, CH2), 6.94–6.98 (2H, m, CH),
7.22–7.30 (3H, m, CH), 7.49–7.64 (4H, m, CH), 7.88–7.93
(2H, m, CH), 8.32–8.35 (1H, m, CH).
O-Benzyl-N-(4,5-dihydro-1H-imidazol-2-yl)-N-
(naphthalen-2-ylmethyl)hydroxylamine 2j
Obtained as an oil; 1H-NMR (200 MHz, CDCl3) d 3.65 (4H, s, CH2),
4.51 (2H, s, CH2), 4.60 (1H, bs, NH), 4.82 (2H, s, CH2), 7.09–7.18
(2H, m, CH), 7.22–7.32 (3H, m, CH), 7.43–7.55 (2H, m, CH),
7.61–7.68 (1H, m, CH), 7.80–7.91 (4H, m, CH); 13C-NMR
(50 MHz, CDCl3) d 45.0, 57.9, 78.7, 126.4, 126.6, 128.1, 128.2,
128.4, 128.5, 129.0, 129.1, 129.2, 129.7, 133.4, 133.8, 134.6, 135.8,
167.5.
O-Benzyl-N-(4-tert-butylbenzyl)-N-(4,5-dihydro-1H-
imidazol-2-yl)hydroxylamine 2d
M.p.: 96–988C; 1H-NMR (500 MHz, CDCl3) d 1.36 (9H, s, CH3), 3.64
(4H, bs, CH2), 4.54 (2H, s, CH2), 4.60 (1H, bs, NH), 4.63 (2H, s, CH2),
7.15–7.17 (2H, m, CH), 7.33–7.35 (4H, m, CH), 7.41–7.43 (3H, m,
CH); 13C-NMR (50 MHz, CDCl3) d 31.9, 35.0, 45.0, 57.2, 78.7, 125.7,
129.0, 129.2, 129.8, 130.1, 133.8, 135.8, 151.1, 167.4; IR (KBr,
cmꢃ1) 3172, 2962, 2865, 1595, 1492, 1457, 1280, 1007, 986,
830, 757, 749, 698.
O-Benzyl-N-(4,5-dihydro-1H-imidazol-2-yl)-N-
(1-phenylethyl)hydroxylamine 2k
M.p.: 72–738C; 1H-NMR (200 MHz, CDCl3) d 1.62 (3H, d, J ¼ 6.8 Hz,
CH3), 3.61 (4H, s, CH2), 4.35 (1H, bs, NH), 4.50–4.60 (2H, m, CH2),
5.34 (1H, q, J ¼ 6.8 Hz, CH), 7.15–7.22 (2H, m, CH), 7.29–7.43
(6H, m, CH), 7.52–7.60 (2H, m, CH); 13C-NMR (50 MHz, CDCl3)
d 15.2, 45.0, 61.3, 79.5, 128.1, 128.6, 129.0, 129.1 (two signals),
129.6, 135.9, 140.8, 167.0; IR (KBr, cmꢃ1) 3156, 3030, 2934, 2880,
1591, 1497, 1453, 1371, 1279, 989, 752, 699.
O-Benzyl-N-(4,5-dihydro-1H-imidazol-2-yl)-N-
(3,5-dimethoxybenzyl)hydroxylamine 2e
M.p.: 66–688C; 1H-NMR (200 MHz, CDCl3) d 3.63 (4H, bs, CH2), 3.79
(6H, s, OCH3), 4.15 (1H, bs, NH), 4.58 (2H, s, CH2), 4.59 (2H, s, CH2),
6.43 (1H, t, J ¼ 2.3 Hz, CH), 6.64 (2H, d, J ¼ 2.3 Hz, CH), 7.19–7.35
(5H, m, CH); 13C-NMR (50 MHz, CDCl3) d 44.5, 55.8, 57.9, 78.7,
100.5, 108.0, 129.0, 129.1, 129.7, 135.9, 139.4, 161.2, 167.5; IR
(KBr, cmꢃ1) 3157, 2946, 2846, 1597, 1463, 1345, 1283, 1203, 1146,
1052, 824, 752, 700.
O-Benzyl-N-(4,5-dihydro-1H-imidazol-2-yl)-N-
phenethylhydroxylamine 2l
M.p.: 76–798C; 1H-NMR (500 MHz, CDCl3) d 3.02 (2H, t, J ¼ 7.5 Hz,
CH2), 3.59 (4H, bs, CH2), 3.78 (2H, t, J ¼ 7.5 Hz), 4.84 (2H, s, OCH2),
4.86 (1H, bs, NH), 7.15–7.45 (10H, m, CH); 13C-NMR (50 MHz,
CDCl3) d 32.4, 42.8, 48.0, 77.5, 126.2, 128.4, 128.7, 128.8,
129.0, 129.1, 135.6, 139.2, 166.1; IR (KBr, cmꢃ1) 3234, 3024,
2930, 2867, 1645, 1607, 1494, 1458, 1374, 1275, 1215, 1063,
1005, 740, 697.
O-Benzyl-N-(biphenyl-2-ylmethyl)-N-(4,5-dihydro-1H-
imidazol-2-yl)hydroxylamine 2f
M.p.: 165–1668C; 1H-NMR (200 MHz, DMSO-d6) d 3.41 (4H, bs,
CH2), 4.48 (2H, s, CH2), 4.50 (2H, s, CH2), 6.00 (1H, bs, NH),
7.03–7.07 (2H, m, CH), 7.25–7.40 (11H, m, CH), 7.59–7.61
(1H, m, CH); 13C-NMR (50 MHz, DMSO-d6) d 45.2, 53.8, 77.1,
127.3, 127.4, 127.5, 128.3 (two signals), 128.4, 129.3, 129.5,
O-Benzyl-N-(4,5-dihydro-1H-imidazol-2-yl)-N-
130.0, 130.1, 134.4, 135.7, 140.8, 142.1, 166.4; IR (KBr, cmꢃ1
3167, 2956, 2854, 1590, 1492, 1456, 1278, 1004, 991, 758, 699.
)
(2-phenylpropyl)hydroxylamine 2m
Obtained as an oil; 1H-NMR (200 MHz, CDCl3) d 1.34 (3H, d,
J ¼ 7.3 Hz, CH3), 3.29 (1H, q, J ¼ 7.3 Hz, CH), 3.52 (4H, s, CH2),
3.75 (2H, d, J ¼ 7.3 Hz, CH2), 4.78 (1H, bs, NH), 4.62–4.78 (2H, m,
OCH2), 7.18–7.40 (10H, m, CH); 13C-NMR (50 MHz, CDCl3) d 20.5,
38.3, 49.5, 60.6, 77.8, 126.8, 128.0, 128.9, 129.1 (two signals),
129.5, 136.1, 145.4, 167.5.
O-Benzyl-N-(biphenyl-3-ylmethyl)-N-(4,5-dihydro-1H-
imidazol-2-yl)hydroxylamine 2g
Obtained as an oil; 1H-NMR (200 MHz, CDCl3) d 3.64 (4H, bs, CH2),
4.45 (1H, bs, NH), 4.56 (2H, s, CH2), 4.71 (2H, s, CH2), 7.14–7.72
(14H, m, CH); 13C-NMR (50 MHz, CDCl3) d 45.0, 57.7, 78.7, 127.0,
127.7, 127.8, 129.1, 129.2 (two signals), 129.3 (two signals), 129.8
(two signals), 135.8, 137.5, 141.4, 141.7, 167.5.
N-(Imidazolidin-2-ylidene)-1-arylalkylamine oxides 3
General procedure: The corresponding hydroxylamine 2 (0.5 g)
was dissolved in methanol (5 mL). The substrate was hydrogen-
ated in the presence of 10% Pd/C (0.05 g) by passing gaseous
hydrogen through the solution (1 h) or with use of pressurized
reactor (0.5 h). The progress of the reaction was monitored by
TLC. The filtration and evaporation of the reaction mixture
furnished a solid residue which upon rinsing with diethyl ether
gave pure product 3. Yields 95–99%. The free bases 3 thus
obtained were converted into corresponding addition salts 4
upon treatment with methanolic solutions of gaseous hydrochlo-
ride or hydrobromide.
N-Benzhydryl-O-benzyl-N-(4,5-dihydro-1H-imidazol-2-
yl)hydroxylamine 2h
M.p.: 118–1208C; 1H-NMR (500 MHz, CDCl3) d 3.28–3.37 (2H, m,
CH2), 3.72–3.81 (2H, m, CH2), 4.30 (2H, bs, CH2), 4.68 (1H, bs, NH),
6.49 (1H, s, CH2), 7.10–7.12 (2H, m, CH), 7.29–7.36 (9H, m, CH),
7.44–7.46 (4H, m, CH); 13C-NMR (125 MHz, CDCl3) d 45.3, 54.4,
69.2, 79.1, 127.5, 128.4, 128.7, 128.8, 129.4, 129.8, 135.5, 139.7,
166.3; IR (KBr, cmꢃ1) 3159, 3062, 3027, 2940, 2870, 1605, 1494,
1454, 1285, 1001, 750, 723, 699.
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