Journal of Inorganic and General Chemistry
ARTICLE
Zeitschrift für anorganische und allgemeine Chemie
(KBr): ν˜max = 3170 (NH), 2958 (CH aliphatic), 2224 (CN), 1704 (CO) 215 °C. IR (KBr): ν˜max = 3392 (NH), 3323,3190 (NH2) cm–1. MS:
1
cm–1. MS: m/z 187 (M+). C10H9N3O (187.20): calcd. C 64.16; H, 4.85;
N, 22.45%; found: C 64.19; H, 4.86; N, 22.48%.
m/z 232 (M+). H NMR ([D6]DMSO): δ = 6.60 (s, 1 H, pyrazol-H),
7.30 (s, 2 H, NH2, NH), 7.8–8.4 (m, 4 H, Ar-H). C9H8N6O2 (232.20):
calcd. C 46.55; H, 3.47; N, 36.19%; found: C 46.58; H, 3.48; N, 36.21.
Synthesis of 3-Oxo-2-(phenyl-hydrazono)propionitrile (3d): The
compound was obtained as yellow crystals (58%), mp. 172 °C. IR
(KBr): ν˜max = 3415 (NH), 2204 (CN), 1661 (CO) cm–1. MS: m/z 173
(M+). C9H7N3O (173.18): calcd. C 62.42; H, 4.07; N, 24.26%; found:
C 62.48; H, 4.00; N, 24.24%.
Synthesis of 4-p-Tolylazo-2H-pyrazol-3-ylamine (7c): This dye was
obtained as orange crystals from ethanol (54%), mp. 198 °C. IR
(KBr): ν
˜
= 3362 (NH), 2922 (CH aromatic), 2854 (CH aliphatic)
max
cm–1. MS: m/z 201 (M+). C10H11N5 (201.23): calcd. C 59.69; H, 5.51;
N, 34.80%; found: C 59.71; H, 5.50; N, 34.79.
Synthesis of 4-(NЈ-[1-Cyano-2-oxo-ethylidene]-hydrazino)-benz-
enesulfonic Acid (3f): A mixture of sulfanilic acid dihydrate (10.5 g,
0.05 mol), anhydrous sodium carbonate (2.65 g, 0.025 mol), and water
(100 mL) are warmed to obtain a clear solution. The mixture was
cooled till 15 °C under tap water and sodium nitrite (3.7 g, 0.059 mol
in 10 mL water) was added. The resulting solution was poured slowly
with stirring into a mixture of conc. HCl (10.5 mL) and crushed ice
(60 g). The resulting p-sulphonatephenyldiazonium chloride solution
was added to a cold solution of 3-piperidinoacrylonitrile 1 (6.8 g, 0.05
mol) in ethanol (200 mL) containing sodium acetate. The mixture was
stirred, and left in a cold place overnight. The solid product was col-
lected by filtration and crystallized from ethanol. The compound was
obtained as orange crystals (83%), mp. 252 °C. IR (KBr): ν˜max = 3515
(OH), 3447 (NH), 2222 (CN), 1687 (SO2), 1652 (CO) cm–1. MS: m/z
Synthesis of 4-Phenylazo-2H-pyrazol-3-ylamine (7d): This dye was
obtained as reddish-brown crystals from ethanol (52%), mp. 196 °C.
IR (KBr): ν˜max = 3424 (NH), 2925 (CH aromatic) cm–1. MS: m/z 187
(M+). 1H NMR ([D6]DMSO): δ = 6.71 (s, 1 H, pyrazol-H), 7.35–7.49
(m, 5 H, Ar-H), 7.67, 7.70 (s, 2 H, NH2), 7.82, 7.89 (s, 1 H, NH).
C9H9N5 (187.21): calcd. C 57.74; H, 4.85; N, 37.41%; found: C 57.76;
H, 4.84; N, 37.43.
Synthesis of 2-(NЈ-[1-Cyano-2-hydrazono-ethylidene]-hydrazino)-
benzoic Acid Methyl Ester (10g): A mixture of 3 (0.01 mol) and
hydrazine hydrate (0.01 mol) in ethanol (25 mL) was heated to reflux
for 2 h and poured into H2O. The solid, so formed, was collected by
filtration and crystallized from ethanol to give brown crystals (66%),
mp. 129 °C. IR (KBr): ν˜max = 3432 (NH), 2947 (CH aromatic), 2866
1
235 (M+). H NMR ([D6]DMSO): δ = 3.36 (OH), 7.49–7.68 (m, 8 H,
(CH aliphatic), 2192 (CN), 1700 (CO) cm–1. MS: m/z 245 (M+). H
NMR ([D6]DMSO): δ = 3.8 (s, 3 H, aliphatic-H), 7.14–8.16 (m, 4 H,
Ar-H), 8.69 (s, 1 H, NH2), 12.74 (s, 1 H, NH). C11H11N5O2 (245.24):
calcd. C 53.87; H, 4.52; N, 28.56%; found: C 53.89; H, 4.51; N, 28.55.
1
Ar–H), 9.5 (s, 1 H, CHO), 12.8 (s, 1 H, NH).13C NMR ([D6]DMSO):
δ = 110.3 (CH aromatic), 114.58 (CN), 115.86,126.94,141.95 (CH aro-
matic), 145.10 (C vinyl), 196.65 (CHO). C9H7N3O4S (253.24): calcd.
C 42.69; H, 2.79; N, 16.59; S, 12.66%; found: C 42.61; H, 2.77; N,
16.65; S, 12.70%.
General Procedure for the Synthesis of N-phenyl-4-(arylazo)-pyr-
azol-3-ylamine 7i and 7j: Phenyl hydrazine (1.1 g, 0.01 mol) was
added to a solution of 3 (0.01 mol) in ethanol (30 mL). The reaction
mixture was heated to reflux for 2 h, and cooled to room temperature.
The separated solid was filtered, washed with water, dried and recrys-
tallized from ethanol.
Synthesis of (2-Cyanophenylhydrazono)-(2-cyanophenylazo)-
acetonitrile (6h): Sodium nitrite (1.5 g in 10 mL H2O) was added to
a cold solution of 2-cyanophenylamine hydrochloride (0.02 mol amine
in 10 mL concentrated HCl) with stirring. The resulting 2-cyanophen-
yldiazonium chloride solution was added to a cold solution of 3-piper-
idinoacrylonitrile 1 (0.01 mol) in ethanol (50 mL) containing sodium
acetate. The mixture was stirred and the solid product was collected
by filtration and crystallized from ethanol to give red crystals (70%),
mp. 190 °C. IR (KBr): ν˜max = 3448 (NH), 2220 (CN) cm–1. MS: (EI,
70 ev): m/z (%) = 299 (M+). 1H NMR ([D6]DMSO): δ = 7.52–7.92
(m, 8 H, Ar-H), 12.22 (s, 1 H, NH).13C NMR ([D6]DMSO): δ = 98.27,
101.81, 104.34, 109.18, 111.84 (CH aromatic), 114, 115, 116.67 (3
CN), 120, 64, 128, 129.23, 134.1, 134.3 (CH aromatic), 147.69 (C
vinyl), 150.2 (CH aromatic). C16H9N7 (299.28): calcd. C 64.21; H,
3.03; N, 32.76%; found: C 64.0; H, 3.04; N, 32.75.
Synthesis of 2-Phenyl-4-p-tolylazo-2H-pyrazol-3-ylamine (7i): This
dye was obtained as orange crystals (84%), mp. 164 °C. IR (KBr):
ν˜max = 3387, 3262 (NH2), 2920 (CH aromatic), 2858 (CH aliphatic)
cm–1. MS: m/z 277 (M+). 1H NMR ([D6]DMSO): δ = 3.3 (s, 3 H,
aliphatic-H), 7.15 (s, 1 H, pyrazol-H), 7.25–7.66 (m, 9 H, Ar-H), 8.02
(s, 2 H, NH2). C16H15N5 (277.33): calcd. C 69.30; H, 5.45; N, 25.25%;
found: C 69.33; H, 5.44; N, 25.26.
Synthesis of 4-(4-Nitro-phenylazo)-2-phenyl-2H-pyrazol-3-ylamine
(7j): This dye was obtained as red crystals (54%), mp. 182 °C. IR
(KBr): ν˜max = 3390 (NH2) cm–1. MS: m/z 308 (M+). 1H NMR
([D6]DMSO): δ = 6.9 (s, 1 H, pyrazol-H), 7.36–7.98 (m, 9 H, Ar-H),
8.34, 8.29 (s, 2 H, NH2). C15H12N6O2 (308.30): calcd. C 58.44; H,
3.92; N, 27.26%; found: C 58.45; H, 3.92; N, 27.27%.
Syntheses of Dyestuffs
General Procedure for the Synthesis of 4-(Arylazo)-2H-pyrazol-3-
ylamine (7a–d): A mixture of 3 (0.01 mol) and hydrazine hydrate
(0.01 mol) in ethanol (25 mL) was heated to reflux for 2 h and poured
into H2O. The solid, so formed was collected by filtration and then
crystallized.
Acknowledgements
The authors are grateful to the National Research Centre of the Arab
Republic of Egypt for financial support.
Synthesis of 4-(2-Nitro-phenylazo)-2H-pyrazol-3-ylamine (7a):
This dye was obtained as brown crystals from ethanol (62%), mp.
184 °C. IR (KBr): ν˜max = 3451 (NH), 3336, 3175 (NH2) cm–1. MS:
1
m/z 232 (M+). H NMR ([D6]DMSO): δ = 5.57 (s, 1 H, pyrazol-H),
References
7.36–7.87 (m, 4 H, Ar-H), 7.92–7.97 (s, 2 H, NH2), 8.17 (s, 1 H, NH).
C9H8N6O2 (232.20): calcd. C 46.55; H, 3.47; N, 36.19%; found: C
46.51; H, 3.49; N, 36.23.
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Torres, C. Núñez, C. Lodeiro, Dalton Trans. 2013, 42, 2107–
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2016, 760, 1–5.
Synthesis of 4-(4-Nitro-phenylazo)-2H-pyrazol-3-ylamine (7b):
This dye was obtained as red crystals from ethanol/H2O (63%), mp.
Z. Anorg. Allg. Chem. 2016, 766–772
771
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