September 2009
Utility of p-Phenylenediformamidine in the Synthesis
of Bisazoles and Phenanthroline
841
N1,N4-Bis(1H-benzo[d]imidazol-2-yl)phenylenediformami-
dine (15). This compound was obtained as yellow crystals
2.72 g (69%) from DMF, mp 296–298ꢀC; ir: 3381, 3178
(NH), 1664 cmꢁ1 (C¼¼N). 1H NMR: d 11.87 (br, 2H, 2NH),
10.14 (br, 2H, 2NH), 8.58, 8.57 (d, 4H, 2benzimidazole-H)
7.38, 7.36 (m, 4H, 2 benzimidazole-H), 7.92 (d, 2H, 2CH¼¼),
7.04 (s, 4H, C6H4). 13C NMR: d 158.69 (CH¼¼N), 152.14,
143.72, 121.51, 110.68 (benzimidazole carbons), 134.75,
117.63 (Phenyl carbon); ms: m/z (Mþ, 72%). Anal. Calcd. for
C22H18N8 (394.43): C, 66.99; H, 4.60; N, 28.41. Found: C,
66.88; H, 4.78; N, 28.63.
N1,N4-Bis(thiazol-2-yl)phenylenediformamidine (16). This
compound was obtained as brown crystals 1.98 g (60%)
from acetone, mp > 300ꢀC; ir: 3248 (NH); 1665 cmꢁ1
(C¼¼N). 1H NMR: d 10.16 (br, 2H, 2NH) 7.75, 7.73 (d, 2H,
J ¼ 8Hz, thiazole-H), 7.40(d, 2H, 2CH¼¼), 7.16 (s, 4H,
C6H4), 6.53, 6.51 ppm (d, 2H, J ¼ 8 Hz, thiazole-H). 13C
NMR: d 159.66 (2CH¼¼N), 169.67, 139.46, 118.11 (thiazole
carbons), 134.74, 117.56 ppm (phenyl carbons); ms: m/z 328
(Mþ, 64%). Anal. Calcd. for C14H12N6S2 (328.42): C, 51.20;
H, 3.68; N, 25.59; S, 19.53. Found: C, 51.01; H, 3.44; N,
25.84; S, 19.78.
d 10.04 (br, 2H, 2NH), 9.45 (br, 2H, 2NH), 8.14 (d, 2H,
2CH¼¼), 8.01 (br, 4H, 2NH2), 8.01 ppm (s, 4H, C6H4). Anal.
Calcd. for C14H14N8O2 (326.31): C, 51.53; H, 4.32; N, 34.34.
Found: C, 51.38; H, 4.03; N, 34.54.
N1,N4-Bis[(3-amino-5-imino-1-phenyl-1H-pyrazol-4(5H)-
ylidene)methyl]benzene-1,4-diamine (10). This compound
was obtained as brown crystals 3.38 g (71%) from DMF/EtOH
(1:1), mp > 300ꢀC; ir: 3435, 3224 (br, NH & NH2); 1667
cmꢁ1 (C¼¼N). 1H NMR: d 10.90 (br, 4H, 2NH2), 10.60 (br,
2H, 2NH), 8.58 (m, 10H, 2C6H5), 7.09,7.07 (d, 2H, J ¼ 8 Hz,
C6H4), 6.54, 6.52 (d, 2H, J ¼ 8 Hz, C6H4), 6.65 (d, 2H,
2CH¼¼), 5.17 (br, 2H, 2NH). Anal. Calcd. for C26H24N10
(476.54): C, 65.53; H, 5.08; N, 29.39. Found: C, 65.35; H,
4.97; N, 29.53.
N1,N4-Bis[(3-amino-5-oxo-1-phenyl-1,4H-pyrazol-4(5H)-
ylidene)methyl]benzene-1,4-diamine (11). This compound
was obtained as brown crystals 3.45 g (72%) from DMF/EtOH
(1:1), mp > 300ꢀC; ir: 3274, 3182 (br, NH & NH2); 1696,
1666 cmꢁ1 (CO). 1H NMR: d 10.83, 10.77, 10.73 (br, 6H,
2NH & 2NH2), 8.47–8.28, 7.54–7.49 (m, 10H, 2C6H5), 7.40
(s, 4H, C6H4), 7.95 (d, 2H, 2CH¼¼). Anal. Calcd. for
C26H22N8O2 (478.51): C, 65.26; H, 4.63; N, 23.42. Found: C,
65.04; H, 4.57; N, 23.56.
Synthesis of 1,10-diaminophenanthroline-2,9-dicarbo-nitrile
(17). A mixture of (5a) 2.6 g (0.01 mol) in bromobenzene
and resublimed aluminum chloride (0.01 mol) was heated
under reflux for 6 h. After cooling, the reaction mixture was
poured onto cold water (40 mL) containing 2 mL of concen-
trated hydrochloric acid, and left to stand for 2 h. The
obtained product was collected by filtration and washed by
water (3 ꢂ 30 mL) and ethanol (3 ꢂ 10 mL). NOE experi-
ment has been done via irradiation of amino protons at d
11.04 ppm enhanced the pyridine protons at d 8.38 ppm and
vice versa while, the aromatic protons was not affected. This
compound was obtained as pale green crystals 1.95 g (75%),
from DMF/EtOH, mp > 300ꢀC; ir: 3320, 3224 (NH2), 2211,
2210 cmꢁ1 (CN); 1H NMR: d 11.04 (br, 4H, 2NH2, D2O-
exchange), 8.38 (s, 2H, pyridine-H), 7.47 ppm (s, 2H, C6H2).
13C NMR: d 136.74, 131.15, 121.51 (aromatic carbons),
117.00, 117.21(CN), 155.65, 149.98, 87.78 (pyridine car-
bons); ms: m/z 260 (Mþ, 100%). Anal. Calcd. for C14H8N6
(260.25): C, 64.61; H, 3.10; N, 32.29. Found: C, 64.65; H,
3.11; N, 32.01.
General procedure for synthesis of bisazoles (19–21). To
a solution of (1) 2.18 g (0.01 mol) in pyridine (20 mL), mor-
pholine or 4-aminopyridine or 3,4-dimethoxyaniline (0.01 mol)
was added. The reaction mixture was heated under reflux for 3
h. The reaction mixture was poured onto ice-cold water. The
obtained product was collected by filtration and washed by
ethanol (3 ꢂ 10 mL). The obtained product was crystallized
from the proper solvent.
Preparation of complex (19). To a solution of (17) 2.6 g
(0.01 mol) in DMF (20 mL), CuCl2ꢃ2H2O, 4.12g (0.01 mol)
solution was added. The reaction mixture was heated under
reflux for 5 h. The solvent was evaporated and the solid
product, so formed, after cooling and water addition was col-
lected by filtration and washed by ether (3 ꢂ 10 mL) and
crystallized from DMF. Compound 19 was obtained as
brown crystals 3.75 g (87%), mp > 250ꢀC; ir: 3440 (OH,
water), 3297, 3219 (NH2), 2215 cmꢁ1 (CN). 1H NMR: d
11.15, 11.12 (s, 4H, 2NH2), 8.48, 8.46 (s, 2H, pyridine-H),
7.43 (s, 2H, C6H4). Anal. Calcd. for C14H12Cl2Cu N6O2
General procedure for synthesis bisazoles (12–16). To a
solution of (1) 2.18 g (0.01 mol) in pyridine (20 mL), hetero-
amines (0.01 mol) was added. The reaction mixture was heated
under reflux for 3 h. The reaction mixture was poured on ice-
cold water. The obtained product was collected by filtration
and washed by ethanol (3 ꢂ 10 mL). The obtained product
was crystallized from the proper solvent.
N1,N4-Bis(5-acetyl-2-(4-chlorophenyl)-2H-1,2,3-triazol-4-yl)
phenylenediformamidine (12). This compound was obtained
as yellow crystals 3.91 g (65%) from DMF/EtOH (1:1), mp >
1
300ꢀC; irir: 3480, 3382 (NH); 1617 cmꢁ1 (C¼¼N). H NMR: d
8.00, 7.98 (d, 4H, C6H4, J ¼ 8.0 Hz), 7.67, 7.66 (d, 4H, C6H4,
J ¼ 8.4 Hz), 7.64 (s, 4H, C6H4), 6.75 (d, 2H, 2CH¼¼), 6.36 (s,
2H, 2NH), 2.59 ppm (s, 6H, 2Me). 13C NMR: d 193.40,
154.91 (triazole carbons), 146.00, 137.95, 132.62, 132.37,
130.16, 120.29 (Ar-carbons), 27.17 (Me); ms: m/z 601 (Mþ,
30%). Anal. Calcd. for C28H22Cl2N10O2 (601.45): C, 55.92; H,
3.69; N, 23.29. Found: C, 56.11; H, 3.92; N, 23.63.
N1,N4-Bis(1H-1,2,4-triazol-3-yl)phenylenediformamidine
(13). This compound was obtained as yellowish brown crystals
1.96 g (66%) from acetic acid, mp 262–263ꢀC; ir: 3439, 3288,
1
3259 (NH), 1684, 1663 cmꢁ1 (C¼¼N). H NMR: d 13.34, 11.51
(s, 4H, 4NH); 7.70 (s, 1H, triazole-H), 7.52 (d, 2H, 2CH¼¼),
7.47 (S, 4H, C6H4). 13C NMR: d 168.70 (CH¼¼N), 160.09,
149.39 (triazole carbons), 135.46, 120.19 (aromatic carbons);
ms: m/z 296 (Mþ, 30%). Anal. Calcd. for C12H12N10 (296.29):
C, 48.64; H, 4.08; N, 47.27. Found: C, 48.43; H, 3.92; N, 47.42.
N1,N4-Bis(4,5-dicyano-1H-imidazole-2-yl)phenylenedifor-
mamidine (14). This compound was obtained as brown crys-
tals 2.17 g (55%) from acetone, mp > 300ꢀC; ir: 3434, 3248
(NH); 2231 (CN), 1666 cmꢁ1 (C¼¼N). 1H NMR: d 11.59 (s,
2H, 2 imidazole-NH), 10.21 (br, 2H, 2NH) 7.97 (d, 2H,
2CH¼¼), 7.59 (s, 4H, C6H4). 13C NMR: d 160.83, 168.70
(2CH¼¼N), 133.92, 117.60 (Ar-carbons), 135.71, 135.05,
121.74, 121.31, 121.22, 121.16 (imidazole carbons), 119.97,
119.93, 119.63, 119.03 (4CN); ms: m/z 394 (Mþ, 8%). Anal.
Calcd. for C18H10N12 (394.35): C, 54.82; H, 2.56; N, 42.62.
Found: C, 54.78; H, 2.72; N, 42.63.
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet