422 Wang et al.
2H, J = 8.4 Hz), 3.52 (t, 2H, J = 8.4 Hz); 13C NMR
(100 MHz, DMSO-d6) δ (ppm): 155.2, 149.1, 148.9,
146.4, 139.5, 135.5, 130.9, 128.5, 123.8, 119.3, 114.4,
46.1, 45.8, 41.7; HRMS (ESI) calculated for C14H16N5
[M + H+] 254.1406, found 254.1402.
resulting gelatinous emulsion was filtered, and the
filtrate was concentrated, affording crude 4a (0.14 g,
30% yield) was purified by silica gel chromatography
(CH2Cl2/CH3OH = 50:1, v/v).
[1-(6-Chloro-pyridin-3-yl-methyl)-imidazolidiny-
lidene]-pyridin-2-yl-amine (3a). Yield, 65%; White
powders; mp: 196.1–197.8◦C; IR (KBr, cm−1): 3435,
1613; 1H NMR (400 MHz, DMSO-d6) δ (ppm):
9.58 (s, 1H), 8.48 (d, 1H, J = 2.0 Hz), 8.30 (d, 2H,
J = 4.4 Hz), 7.91 (dd, 1H, J = 8.0 Hz, J = 2.0 Hz),
7.82 (t, 1H, J = 8.4 Hz), 7.57 (d, 1H, J = 8.0 Hz),
7.16 (d, 1H, J = 8.0 Hz), 7.11 (t, 1H, J = 6.0 Hz),
4.76 (s, 2H), 3.72 (t, 2H, J = 8.4 Hz), 3.33 (t, 2H,
J = 8.4 Hz);13C NMR (100 MHz, DMSO-d6) δ (ppm):
156.6, 150.2, 149.8, 144.2, 140.0, 139.8, 138.5, 131.6,
124.9, 119.1, 118.2, 46.7, 45.1, 42.0; HRMS (ESI)
calculated for C14H15N5Cl [M + H+] 288.1016, found
288.1009.
[1-Pyridin-4-yl-methyl-imidazolidinylidene]-pyri-
din-2-yl-amine (3e).. Yield, 62%; White powders;
1
mp: 191.8–193.6◦C; IR (KBr, cm−1): 3428, 1605; H
NMR (400 MHz, DMSO-d6) δ (ppm): 9.76 (br, 1H),
8.60 (d, 1H, J = 3.6 Hz), 8.34 (s, 1H) 7.86 (t, 1H,
J = 6.4 Hz), 7.40 (d, 2H, J = 3.2 Hz), 7.22–7.09
(m, 2H), 4.82 (s, 2H), 3.77 (t, 2H, J = 8.4 Hz), 3.59
(t, 2H, J = 8.4 Hz);13C NMR (100 MHz, DMSO-d6)
δ (ppm): 155.6, 149.9, 146.4, 144.7, 139.4, 127.7,
122.2, 119.1, 114.6, 47.2, 46.4, 41.7; HRMS (ESI)
calculated for C14H16N5 [M + H+] 254.1406, found
254.1416.
[1-Benzyl-imidazolidinylidene]-pyridin-2-yl-amine
(3f). Yield, 65%; light yellow powders; mp: 138.9–
140.6◦C; IR (KBr, cm−1): 3434, 1613; 1H NMR
(400 MHz, DMSO-d6) δ (ppm): 9.89 (br, 1H), 8.36
(dd, 1H, J = 5.2 Hz, J = 1.2 Hz), 7.93 (t, 1H,
J = 7.6 Hz), 7.46–7.32 (m, 6H), 7.24 (t, 1H,
J = 5.2 Hz), 4.81 (s, 2H), 3.79 (t, 2H, J = 8.8 Hz),
3.56 (t, 2H, J = 8.8 Hz); 13C NMR (100 MHz, DMSO-
d6) δ (ppm): 155.4, 153.4, 146.6, 139.5, 138.0, 134.9,
128.8, 127.6, 119.5, 116.7, 114.1, 111.6; HRMS (ESI)
calculated for C15H17N4 [M + H+] 253.1453, found
253.1448.
[1-(2-Chloro-thiazol-5-yl-methyl)-imidazolidiny-
lidene]-pyridin-2-yl-amine (3b). Yield, 62%; light
yellow powders; mp: 134.6–135.9◦C; IR (KBr, cm−1):
3433, 1623; 1H NMR (400 MHz, DMSO-d6) δ (ppm):
9.99 (br, 1H), 8.36 (d, 1H, J = 2.4 Hz), 7.98 (t,
1H, J = 8.4 Hz) 7.82 (s, 1H), 7.34 (d, 1H, J = 8.0
Hz), 7.27 (t, 1H, J = 6.0 Hz), 4.99 (s, 2H), 3.75 (t,
2H, J = 8.4 Hz) 3.66 (t, 2H, J = 8.4 Hz); 13C NMR
(100 MHz, DMSO-d6) δ (ppm): 161.3, 158.5, 151.1,
146.6, 140.9, 137.4, 135.7, 118.9, 115.8, 46.3, 45.7,
41.0; HRMS (ESI) calculated for C12H13N5SCl [M +
H+] 294.0580, found 294.0566.
[1-Furan-2-yl-methyl-imidazolidinylidene]-pyri-
din-2-yl-amine (3g). Yield, 66%; light yellow pow-
ders; mp: 214.8–216.2◦C; IR (KBr, cm−1): 3428,
1615; 1H NMR (400 MHz, DMSO-d6) δ (ppm):
10.37 (s, 1H), 8.47 (d, 1H, J = 8.0 Hz), 8.21 (d, 1H,
J = 4.4 Hz), 7.77 (t, 1H, J = 8.0 Hz), 7.38 (s, 1H),
7.13 (t, 1H, J = 6.0 Hz), 6.81 (d, 1H, J = 3.2 Hz),
6.35 (s, 1H), 5.43 (s, 2H), 3.93 (t, 2H, J = 9.2
Hz), 3.82 (t, 2H, J = 9.2 Hz); 13C NMR (100 MHz,
DMSO-d6) δ (ppm): 155.3, 148.1, 146.8, 143.6, 139.7,
138.0, 119.9, 116.7, 113.9, 110.7, 46.3, 41.8, 40.0;
HRMS (ESI) calculated for C13H15N4O [M+H+]
243.1246, found 243.1242.
[1-Pyridin-2-yl-methyl-imidazolidinylidene]-pyri-
din-2-yl-amine (3c). Yield, 60%; white powders;
mp: 149.3–151.1◦C; IR (KBr, cm−1): 3428, 1596;
1H NMR (400 MHz, DMSO-d6) δ (ppm): 9.94 (s,
1H), 8.59 (d, 1H, J = 4.4 Hz), 8.37 (dd, 1H, J = 0.8
Hz, J = 4.0 Hz), 7.93–7.86 (m, 2H), 7.49 (d, 1H,
J = 7.6 Hz), 7.37 (t, 1H, J = 7.6 Hz), 7.27–7.22 (m,
2H), 4.94 (s, 2H), 3.83 (t, 2H, J = 8.4 Hz), 3.67 (t,
2H, J = 8.4 Hz); 13C NMR (100 MHz, DMSO-d6)
δ (ppm): 155.5, 154.3, 153.4, 146.8, 139.6, 138.0,
137.3, 123.0, 122.2, 116.8, 112.8, 49.0, 46.9, 42.0;
HRMS (ESI) calculated for C14H16N5 [M + H+]
254.1406, found 254.1398.
[1-Thiophen-2-yl-methyl-imidazolidinylidene]-py-
ridin-2-yl-amine (3h). Yield, 64%; white powders;
mp: 210.8–212.4◦C; IR (KBr, cm−1): 3438, 1613;
1H NMR (400 MHz, DMSO-d6) δ (ppm): 10.35 (br,
1H), 8.42 (d, 1H, J = 8.4 Hz), 8.22 (d, 1H, J = 3.2
Hz), 7.76 (t, 1H, J = 7.2 Hz), 7.34 (d, 1H, J = 3.2
Hz), 7.28 (d, 1H, J = 5.2 Hz), 7.12 (t, 1H, J = 7.2
Hz), 6.99 (t, 1H, J = 3.6 Hz), 5.60 (s, 2H), 3.91 (t,
2H, J = 5.6 Hz), 3.76 (t, 2H, J = 5.6 Hz); 13C NMR
[1-Pyridin-3-yl-methyl-imidazolidinylidene]-pyri-
din-2-yl-amine (3d). Yield, 58%; White powders;
mp: 149.3–151.1◦C; IR (KBr, cm−1): 3436, 1595;
1H NMR (400 MHz, DMSO-d6) δ (ppm): 9.65 (br,
1H), 8.63 (s, 1H), 8.56 (d, 1H, J = 3.6 Hz), 8.31
(d, 1H, J = 4.0 Hz), 7.86–7.81 (m, 2H), 7.44 (dd,
1H, J = 4.8 Hz, J = 2.8 Hz), 7.20 (d, 1H, J = 8.4
Hz), 7.13 (t, 1H, J = 5.6 Hz) 4.78 (s, 2H), 3.73 (t,
Heteroatom Chemistry DOI 10.1002/hc