6
98
A. Yahyazadeh, H. Yousefi / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 117 (2014) 696–701
Scheme 2. Synthetic routes for the preparation of hetarylazo dyes 1–8.
8
.0 mmol) and water (6.0 ml). The resulting solution was vigor-
Dye (4)
Red crystals (Yield: 86%, Mp: 277–278 °C). FT-IR (KBr):
ously stirred at about 0–4 °C for 2 h, while the pH of the reaction
mixture was maintained 10-11 by adding 2.5% sodium hydroxide
solution. The progress of the reaction was followed by TLC, using
m
H
(cm ) = 3432 (OH), 3206 (NH), 3053 (Aro.-H), 1672 (C@O); 1
ꢁ1
6
NMR (400 MHz, DMSO-d ); d 15.52 and 14.50 (b, hydrazone NH),
(
ethyl acetate + petroleum ether) mixture (5:1 v/v) as solvent.
10.91 and 10.55 (b, amide NH), 8.10 (1H, d, J = 8.4 Hz), 7.82 (1H,
d, J = 8.0 Hz), 7.76 (1H, d, J = 8.8 Hz), 7.70 (1H, s), 7.22 (1H, dd,
J = 8.8, 8.0 Hz), 7.10 (1H, d, J = 8.4 Hz), 3.79 (3H, s). Anal. Calcd.
Afterwards, the pH of reaction mixture was regulated 4-5 by
means of a 10% hydrochloric acid solution. At the end of the proce-
dure, the resulting solid was filtered, washed thoroughly with cold
4 3
for C17H11ClN O S: C, 52.79; H, 2.87; N, 14.48; S, 8.29. Found: C,
2
ethanol and dried. Recrystallization from DMF-H O ended in pure
52.72; H, 2.82; N, 14.55; S, 8.31.
crystals of the dye. The physical and spectral data of the purified
dyes are as follows.
Dye (5)
Brown crystals (Yield: 75%, Mp: >350 °C). FT-IR (KBr):
m
H
(
cm ) = 3445 (OH), 3243 (NH), 3023 (Aro.-H), 1690 (C@O); 1
ꢁ
1
Dye (1)
6
NMR (400 MHz, DMSO-d ); d 15.22 and 14.43 (b, hydrazone NH),
11.10 and 10.60 (b, amide NH), 8.78 (1H, s), 8.39 (1H, d,
J = 8.4 Hz), 7.80 (1H, d, J = 8.0 Hz), 7.64 (1H, d, J = 8.4 Hz), 7.40
Red crystals (Yield: 86%, Mp: 271–272 °C). FT-IR (KBr):
cm ) = 3440 (OH), 3202 (NH), 3075 (Aro.-H), 1698 (C@O);
NMR (400 MHz, DMSO-d ); d 15.30 and 14.50 (b, hydrazone NH),
6
m
H
ꢁ1
1
(
(
H
2
1H, d, J = 8.4 Hz), 7.14 (1H, dd, J = 8.8, 8.0 Hz). Anal. Calcd. for C16-
ClN S: C, 47.83; H, 2.01; N, 17.43; S, 7.98. Found: C, 47.79; H,
.04; N, 17.50; S, 7.92.
1
0.93 and 10.61 (b, amide NH), 7.98 (1H, d, J = 7.9 Hz), 7.82 (1H,
d, J = 8.4 Hz), 7.68 (1H, d, J = 2.9 Hz), 7.55 (1H, d, J = 2.9 Hz), 7.23
1H, dd, J = 8.4, 7.9 Hz). Anal. Calcd. for C12 ClN S: C, 46.99;
H, 2.30; N, 18.27; S, 10.45. Found: C, 46.86; H, 2.33; N, 18.32; S,
0.50.
8
5 4
O
(
H
7
4 2
O
Dye (6)
Clear yellow crystals (Yield: 92%, Mp: 265–267 °C). FT-IR (KBr):
1
ꢁ1
m
(cm ) = 3430 (OH), 3210 (NH), 3014 (Aro.-H), 1652 (C@O); 1
NMR (400 MHz, DMSO-d ); d 15.42 and 14.86 (b, hydrazone NH),
0.88 and 10.53 (b, amide NH), 7.98 (1H, d, J = 8.0 Hz), 7.82 (1H,
d, J = 8.4 Hz), 7.23 (1H, dd, J = 8.4, 8.0 Hz), 6.60 (1H, s),), 2.65 (3H,
s). Anal. Calcd. for C13 ClN : C, 51.25; H, 2.98; N, 18.39. Found:
H
Dye (2)
Clear orange crystals (Yield: 84%, Mp: 315–316 °C). FT-IR (KBr):
6
1
ꢁ1
1
m
(cm ) = 3428 (OH), 3198 (NH), 3078 (Aro.-H), 1662 (C@O); H
6
NMR (400 MHz, DMSO-d ); d 15.32 and 14.41 (b, hydrazone NH),
0.85 and 10.52 (b, amide NH), 8.00 (1H, d, J = 8.2 Hz), 7.87 (1H,
d, J = 7.2 Hz), 7.78 (1H, d, J = 7.6 Hz), 7.45–7.35 (3H, m, overlapped),
H
9
5 3
O
1
C, 51.19; H, 3.04; N, 18.29.
7
5
1
9 4 2
.21 (1H, dd, J = 8.2, 7.6 Hz). Anal. Calcd. for C16H ClN O S: C,
3.86; H, 2.54; N, 15.70; S, 8.99. Found: C, 53.82; H, 2.56; N,
5.66; S, 9.01.
Dye (7)
Yellow crystals (Yield: 81%, Mp > 350 °C). FT-IR (KBr):
m
H
ꢁ1
1
(
cm ) = 3415 (OH), 3198 (NH), 3068 (Aro.-H), 1681 (C@O); d
NMR (400 MHz, DMSO-d
6
); 15.95 and 15.24 (b, hydrazone NH),
1
4.38 (NH), 10.87 and 10.48 (b, amide NH), 8.48 (1H, s), 8.10
Dye (3)
Orange crystals (Yield: 77%, Mp: 294–295 °C). FT-IR (KBr):
(
1H, d, J = 7.8 Hz), 7.60 (1H, d, J = 8.4 Hz), 7.25 (1H, dd, J = 8.4,
m
H
ꢁ1
1
7.8 Hz). Anal. Calcd. for C17H ClN O : C, 45.45; H, 2.43; N, 28.91.
Found: C, 45.52; H, 2.46; N, 28.52.
(
cm ) = 3436 (OH), 3211 (NH), 3054 (Aro.-H), 1682 (C@O);
7
6 2
6
NMR (400 MHz, DMSO-d ); d 15.35 and 14.45 (b, hydrazone NH),
1
0.90 and 10.60 (b, amide NH), 7.98 (1H, d, J = 7.6 Hz), 7.88 (1H,
s), 7.83 (1H, d, J = 7.6 Hz), 7.74 (1H, d, J = 8.4 Hz), 7.32 (1H, d,
J = 7.6 Hz). 7.22 (1H, dd, J = 8.4, 7.6 Hz), 2.45 (3H, s). Anal. Calcd.
Dye (8)
Yellow crystals (Yield: 79%, Mp: 260–262 °C). FT-IR (KBr):
m
H
(cm ) = 3438 (OH), 3212 (NH), 3056 (Aro.-H), 1685 (C@O); 1
ꢁ1
for C17
H
11ClN
4
O
2
S: C, 55.06; H, 2.99; N, 15.11; S, 8.65. Found: C,
5
4.99; H, 3.02; N, 15.15; S, 8.71.
6
NMR (400 MHz, DMSO-d ); d 15.67 and 14.90 (b, hydrazone NH),