6030 Yildirim et al.
Asian J. Chem.
(KBr, υmax, cm-1): 3460, 3381, 3346, 3208, 3050-2950, 1624,
1601, 1506, 1431. λmax/nm (CH2Cl2): 266, 300, 490. δH 4.13
(s, 2H, NH2), 6.76 (d, J 8.0, 2H,ArH), 7.03 (t, J 8.0, 1H,ArH),
7.31-7.44 (m, 7H, ArH), 7.80 (d, J 8.0, 2H, ArH), 8.13 (d, J
8.0, 2H,ArH), 15.00 (s, 1H, NH). δC 149.73 (N-C=N), 145.09,
143.89, 140.84, 137.77, 129.45, 128.26, 127.41, 125.97,
124.33, 122.95, 114.92 (ArC). m/z (ESI) for C19H17N5: calcd.
[M + H]+: 316.1557; found: 316.1530. Anal. calc.: C 72.36, H
5.43, N 22.21 (%). Found: C 72.56, H 5,43, N 22.96 (%).
1-(p-Aminophenyl)-3-(p-methoxycarbonylphenyl)-5-
phenylformazan (2b): (2.98 g, 80 %) was obtained as deep
red crystals of m.p. 212 °C. (KBr, υmax, cm-1): 3464, 3364,
3208, 3050-2952, 1704, 1625, 1503, 1434. λmax/nm (CH2Cl2):
253, 360, 490. δH 3.93 (s, 3H, OCH3), 4.17 (s, 2H, NH2), 6.78
(d, J 8.4, 2H,ArH), 7.07 (t, J 7.2, 1H, ArH), 7.35-7.44 (m, 4H,
ArH), 7.80 (d, J 8.4, 2H, ArH), 8.08 (d, J 8.0, 2H, ArH), 8.21
(d, J 8.0, 2H,ArH), 15.26 (s, 1H, NH). δC 167.29 (C=O), 149.94
(N-C=N), 144.81, 143.53, 142.33, 139.77, 129.66, 129.43,
128.51, 125.48, 124.39, 123.56, 115.21, 115.11, 114.94 (ArC),
52.04 (OCH3). m/z (ESI) for C21H19N5O2 calcd. [M + H]+:
374.1561; found: 374.1531. Anal. calcd. : C 67.55, H 5.13, N
18.76 (%). Found: C 67.86, H 5.04, N 18.74 (%).
1-(p-Aminophenyl)-3-(p-nitrophenyl)-5-phenyl-
formazan (2c): (2.63 g, 73 %) was obtained as deep red
crystals of m.p. 231 °C. (KBr, υmax, cm-1): 3472, 3377, 3210,
3020, 1620, 1500, 1446. λmax/nm (CH2Cl2): 264, 397, 481. δH
= 4.20 (s, 2H, NH2), 6.78 (d, J 8.4, 2H, ArH), 7.10 (t, J 8.0,
1H, ArH), 7.30- 7.44 (m, 6H, ArH), 7.79 (d, J 8.4, 2H, ArH),
8.28 (d, J 8.4, 2H,ArH), 15.40 (t, 1H, NH). δC 129.53, 125.97,
125.01, 124.49, 124.13, 123.76, 115.44, 114.97 (ArC). m/z
(ESI) for C19H16N6O2 calcd. [M + H]+: 361.1408; found:
361.1337. Anal. calcd.: C 63.30, H 4.40, N 23.30 (%). Found:
C 63.04, H 4.46, N 22.95 (%).
1-(p-Aminophenyl)-3-(p-cyanophenyl)-5-phenyl-
formazan (2d): (2.79 g, 82 %) was obtained as claret red
crystals of m.p. 220 °C. (KBr, υmax, cm-1): 3476, 3377, 3212,
3030, 2207, 1628, 1487, 1451. λmax/nm (CH2Cl2): 252, 362,
484. δH 4.17 (s, 2H, NH2), 6.77 (d, J 8.5, 2H, ArH), 7.09 (t, J
7.0, 1H, ArH), 7.35-7.43 (m, 4H, ArH), 7.68 (d, J 8.5, 2H,
ArH), 7.78 (d, J 8.7, 2H, ArH), 8.24 (d, J 8.7, 2H, ArH), 15.31
(s, 1H, NH). δC 144.66 (N-C=N), 138.91, 132.13, 129.49,
125.95, 124.45, 123.90, 115.30, 114.95 (ArC), 110.13 (-CN).
m/z (ESI) for C20H16N6 calcd. [M + H]+: 341.1509; found:
341.1477. Anal. calcd.: C 70.50, H 4.70, N 24.70 (%). Found:
C 69.92, H 4.71, N 24.56 (%).
1-(p-Aminophenyl)-3-(p-chlorophenyl)-5-phenyl-
formazan (2e:) (2.34 g, 67 %) was obtained as claret red
crystals of m.p. 209 °C. (KBr, υmax, cm-1): 3468, 3354, 3211,
2920, 2853, 1625, 1511, 1470. λmax/nm (CH2Cl2): 264, 325,
387, 510. δH 4.16 (s, 2H, NH2), 7.03 (d, J 6.9, 2H, ArH), 7.05
(t, J 3.9, 1H,ArH), 7.26-7.52 (m, 6H,ArH), 7.78 (d, J 8.7, 2H,
ArH), 8.06 (d, J 8.7, 2H, ArH), 15.04 (s, 1H, NH). δC 149.90
(N-C=N), 144.94, 143.67, 139.94, 136.35, 133.18, 129.40,
128.36, 127.19, 124.38, 123.18, 114.96, 114.93 (ArC). m/z
(ESI) for C19H16ClN6 calcd. [M + H]+: 350.1167; found:
350.1123. Anal. calcd.: C 65.33, H, 4.58, N 20.06 (%). Found:
C 65.62, H 5.02, N 19.68 (%).
crystals of m.p. 207 °C. (KBr, υmax, cm-1): 3464, 3322, 3213,
3037, 1621, 1504, 1448. λmax/nm (CH2Cl2): 264, 326, 384,
508. dH 4.16 (s, 2H, NH2), 6.77 (d, J 8.7, 2H, ArH), 7.04 (t, J
6.8, 1H, ArH), 7.26-7.69 (m, 6H, ArH), 7.78 (d, J 8.5, 2H,
ArH), 8.00 (d, J 8.5, 2H, ArH), 15.05 (s, 1H, NH). δC 148.90
(N-C=N), 143.88, 142.63, 138.93, 135.80, 130.27, 128.37,
126.49, 123.36, 122.19, 120.19, 120.44, 113.95, 113.91 (ArC).
m/z (ESI) for C19H16BrN6 calcd. [M + H]+: 394.0662; found:
394.0558. Anal. calcd.: C 57.72, H 4.05, N 17.72 (%). Found:
C 57.01, H 4.19, N 17.93 (%).
General procedure for the synthesis of compounds (3a-
f): The hydrazones 1a-f (0.02 mol) was dissolved in methanol
(70 mL) and sodium hydroxide (3.52 g) was added to this
solution. Diazonium chloride of benzidine was prepared from
benzidine (1.84 g, 0.01 mol) in concentrated HCl (5 mL) with
sodium nitrite (1.52 g, 0.02 mol) in water (10 mL). This
solution was added to the hydrazone solution at -5 °C. This
mixture was stirred for 2 h at -5 °C. and stored 2 days. Each
bis formazan compounds 3a-f were purified by flash column
chromatography over silica gel. (EtOAc-hexane, 1:4)
1,1'-([1,1'-Biphenyl]-4,4'-yl)bis(3,5-diphenylformazan)
(3a): (3.05 g, 51 %) was obtained as deep red crystals of m.p.
175 °C. (KBr, υmax, cm-1): 3062, 2960, 2924, 1593, 1510, 1443.
λmax/nm(CH2Cl2): 260, 303, 501. δH 6.99 (t, J 2.4, 2H, ArH),
7.13-7.38 (m, 8H,ArH), 7.46 (m, 6H,ArH), 7.70 (m, 4H,ArH),
7.79 (d, J 8.4, 4H, ArH), 8.16 (d, J 8.4, 4H, ArH), 15.23 (s,
2H, NH ). δC 128.43, 127.88, 127.39, 127.06, 126.66, 125.92,
124.83, 118.52, 117.47 (ArC). m/z (ESI) for C38H30N8 calcd.
[M + H]+: 599.2653; found: 599.2681. Anal. calcd.: C 76.23,
H 5.05, N 18.72 (%). Found: C 76.02, H 5.71, N 18.66 (%).
1,1'-([1,1'-Biphenyl]-4,4'-yl)bis(3-(p-methoxycar-
bonylphenyl)-5-phenylformazan (3b): (4.00 g, 56 %) was
obtained as deep red crystals of m.p. 200 °C. (KBr, υmax, cm-1):
3287, 3046, 2948, 1715, 1601, 1494, 1431. λmax/nm (CH2Cl2):
251, 335, 495. δH 3.87 (s, 6H, OCH3), 7.18 (t, J 7.4, 2H,ArH),
7.31 (d, J 8.5, 4H, ArH), 7.40 (d, J 7.6, 4H, ArH), 7.56-7.64
(m, 4H, ArH), 7.70 (d, J 8.5, 4H, ArH), 8.02 (d, J 8.5, 4H,
ArH), 8.14 (d, J 8.5, 4H, ArH), 15.64 (t, 2H, NH ). δC 166.17
(-C=O), 146.28 (N-C=N), 140.84, 140.02, 139.08, 128.78,
128.50, 128.25, 127.91, 127.77, 127.11, 126.68, 126.56,
125.93, 124.36, 118.71, 117.59, 112.10 (ArC), 51.06 (OCH3).
m/z (ESI) for C42H34N8O4 calcd. [M + H]+: 715.2762; found:
715.2742. Anal. calcd.: C 70.58, H 4.79, N 15.68 (%). Found:
C 70.72, H 4.80, N 15.56 (%).
1,1'-([1,1'-Biphenyl]-4,4'-yl)bis(3-(p-nitrophenyl)-5-
phenylformazan (3c): (4.27 g, 62 %) was obtained as deep
red crystals of m.p. 168 °C. (KBr, υmax, cm-1): 3066, 3027,
2924, 1664, 1506, 1451. λmax/nm (CH2Cl2): 265, 380, 491. δH
7.35 (t, J 7.8, 2H, ArH), 7.43 (d, J 7.4, 4H, ArH), 7.52 (d, J
7.4, 4H, ArH), 7.68- 7.77 (m, 8H, ArH), 7.83 (d, J 8.4, 4H,
ArH), 8.33 (d, J 8.4, 4H, ArH), 15.88 (s, 2H, NH ). δC 146.09
(N-C=N), 128.59, 127.93, 127.19, 126.93, 126.81, 125.95,
124.89, 122.86, 118.87, 117.68 (ArC). m/z (ESI) for
C38H28N10O4 calcd. [M + H]+: 689.2376; found: 689.2356.Anal.
calcd.: C 66.27, H 4.10, N 20.34 (%). Found: C 66.92, H 4.12,
N 20.60 (%).
1,1'-([1,1'-Biphenyl]-4,4'-yl)bis(3-(p-cyanophenyl)-5-
phenylformazan (3d): (4.22 g, 65 %) was obtained as deep
red crystals of m.p. 154 °C. (KBr, υmax, cm-1): 3050, 2964,
1-(p-Aminophenyl)-3-(p-bromophenyl)-5-phenyl-
formazan (2f): (2.99 g, 76 %) was obtained as claret red