Z. Arghiani, S. M. Seyedi, M. Bakavoli, and H. Eshghi
Vol 000
3-Chloro-6-(2-(4-chlorobenzylidene)hydrazinyl)-4-(4-methoxy-
phenyl)pyridazine (7j). This compound was obtained as a yellow
powder in 38% yield, mp 208–209°C; IR (potassium bromide):
3052–3020cmÀ1 1H nmr (DMSO-d6): δ 7.52–7.84 (m, 8H,
;
Ar–H), 8.30–8.56 (m, 2H, Ar–H), 8.61 (s, 1H, CH-pyridazine);
ms: m/z 306, 308 (M+); Anal. Cald for C17H11ClN4: C, 66.56;
H, 3.61; N, 18.26. Found: C, 66.65; H, 3.42; N, 17.71. The
1H nmr spectra data were compared with the authentic sample
of ref. [21,22].
(NH) 3191, (N=CH) 1609 cmÀ1 1H nmr (DMSO-d6): δ 3.90
;
(s, 3H, OCH3), 7.13 (d, 2H, Ar–H), 7.44–7.76 (m, 4H, Ar–H),
7.96 (d, 2H, Ar–H), 8.10 (s, 1H, CH-pyridazine), 8.72 (s, 1H,
N=CH), 11.95 (br s, 1H, NH, D2O exchangeable); Anal. Calcd
for C18H14Cl2N4O: C, 57.92; H, 3.78; N, 15.01. Found: C,
57.70; H, 3.55; N, 14.78.
6-Chloro-3-(4-methoxyphenyl)-7-phenyl-[1,2,4]triazolo[4,3-
b]pyridazine (8b). This compound was obtained as a yellow
powder in 20% yield, mp 140–142°C; IR (potassium bromide):
(=C–H) 3060–3039, (–C–H) 2917–2848 cmÀ1
;
1H nmr
6-(2-Benzylidenehydrazinyl)-3-chloro-4-(p-tolyl)pyridazine
(7k). This compound was obtained as a light yellow powder in
60% yield, mp 295–297°C; IR (potassium bromide): (NH)
(deuteriochloroform): δ 3.95 (s, 3H, OCH3), 7.10 (d, 2H,
Ar–H), 7.45–7.67 (m, 5H, Ar–H), 8.10 (s, 1H, CH-pyridazine),
8.55 (d, 2H, Ar–H); ms: m/z 336, 338 (M+); Anal. Cald for
C18H13ClN4O: C, 64.19; H, 3.89; N, 16.64. Found: C, 63.87; H,
1
3199, (N=CH) 1608 cmÀ1; H nmr (DMSO-d6): δ 2.35 (s, 3H,
CH3), 7.34–7.86 (m, 10H, Ar–H, N=CH), 8.20 (s, 1H, CH-
pyridazine), 11.88 (br s, 1H, NH, D2O exchangeable); Anal.
Calcd for C18H15ClN4: C, 66.98; H, 4.68; N, 17.36. Found:
C, 66.90; H, 4.60; N, 17.23.
3-Chloro-6-(2-(4-methoxybenzylidene)hydrazinyl)-4-(p-tolyl)
4.60; N, 16.45.
6-Chloro-7-phenyl-3-(p-tolyl)-[1,2,4]triazolo[4,3-b]pyridazine
(8c). This compound was obtained as a pale yellow powder in
45% yield, mp 161–162°C; IR (potassium bromide): (=C–H)
3051–3018, (–C–H) 2912–2855 cmÀ1 1H nmr (DMSO-d6): δ
;
pyridazine (7l).
powder in 35% yield, mp 206–208°C; IR (potassium bromide):
(NH) 3182, (–C–H) 2970–2835, (N=CH) 1603 cmÀ1 1H nmr
This compound was obtained as a yellow
2.40 (s, 3H, CH3), 7.45 (d, 2H, Ar–H), 7.54–7.89 (m, 5H, Ar–H),
8.39 (d, 2H, Ar–H), 8.50 (s, 1H, CH-pyridazine); ms: m/z 321,
323 (M+); Anal. Cald for C18H13ClN4: C, 67.40; H, 4.08; N,
;
(deuteriochloroform): δ 2.45 (s, 3H, CH3), 3.90 (s, 3H, OCH3),
6.93 (d, 2H, Ar–H), 7.30–7.76 (m, 4H, Ar–H), 7.85 (d, 2H,
Ar–H), 8.23 (s, 1H, CH-pyridazine), 8.70 (s, 1H, N=CH), 11.17
(br s, 1H, NH, D2O exchangeable); Anal. Calcd for
C19H17ClN4O: C, 64.68; H, 4.86; N, 15.88. Found: C, 64.50;
H, 4.60; N, 15.87.
17.47. Found: C, 67.20; H, 4.00; N, 17.31.
6-Chloro-3-(4-nithrophenyl)-7-phenyl-[1,2,4]triazolo[4,3-b]
pyridazine (8d).
This compound was obtained as a light
brown powder in 68% yield, mp 220–221°C; IR (potassium
1
bromide): (=C–H) 3068 cmÀ1; H nmr (DMSO-d6): δ 7.50–7.75
3-Chloro-6-(2-(4-methylbenzylidene)hydrazinyl-4-(p-tolyl)
(m, 5H, Ar–H), 8.44–8.77 (m, 5H, CH-pyridazine, Ar–H); ms: m/z
351 (M+); Anal. Cald for C17H10ClN5O2: C, 58.05; H, 2.84; N,
pyridazine (7m).
powder in 30% yield, mp 232–234°C; IR (potassium bromide):
(NH) 3178, (–C–H) 2945–2847, (N=CH) 1609 cmÀ1 1H nmr
This compound was obtained as a yellow
19.91. Found: C, 58.00; H, 2.63; N, 19.81.
6-Chloro-3-(4-chlorophenyl)-7-phenyl-[1,2,4]triazolo[4,3-b]
;
pyridazine (8e). This compound was obtained as a pale yellow
powder in 50% yield, mp 180–181°C; IR (potassium bromide):
(deuteriochloroform): δ 2.30 (s, 3H, CH3), 2.42 (s, 3H, CH3),
7.15–7.75 (m, 6H, Ar–H), 7.86 (d, 2H, Ar–H), 8.20 (s, 1H, CH-
pyridazine), 8.74 (s, 1H, N=CH), 11.77 (br s, 1H, NH, D2O
exchangeable); Anal. Calcd for C19H17ClN4: C, 67.75; H, 5.09;
N, 16.63. Found: C, 67.80; H, 4.76; N, 16.54.
3-Chloro-6-(2-(4-nitrobenzylidene)hydrazinyl-4-(p-tolyl)
(=C–H) 3051–3018 cmÀ1 1H nmr (DMSO-d6): δ 7.50–7.91
;
(m, 7H, Ar–H), 8.39–8.65 (m, 3H, Ar–H, CH-pyridazine); ms:
m/z 341, 343 (M+); Anal. Cald for C17H10Cl N4: C, 59.84; H,
2
2.95; N, 16.42. Found: C, 59.77; H, 2.94; N, 16.40.
6-Chloro-7-(4-methoxyphenyl)-3-phenyl-[1,2,4]triazolo[4,3-b]
pyridazine (7n).
powder in 80% yield, mp 300–302°C; IR (potassium bromide):
(NH) 3207, (N=CH) 1609 cmÀ1 1H nmr (DMSO-d6): δ 2.35
This compound was obtained as an orange
pyridazine (8f).
powder in 48% yield, mp 158–159°C; IR (potassium bromide):
(=C–H) 3072–3007 cmÀ1 1H nmr (deuteriochloroform): δ 3.90
This compound was obtained as a yellow
;
;
(s, 3H, CH3) 7.38–7.56 (m, 6H, Ar–H), 7.92 (s, 1H,
N=CH), 8.01 (s, 1H, CH-pyridazine), 8.30 (d, 2H, Ar–H),
12.27 (br s, 1H, NH, D2O exchangeable); Anal. Calcd for
C18H14ClN5O2: C, 58.78; H, 3.84; N, 19.04. Found: C,
(s, 3H, OCH3), 7.11 (d, 2H, Ar–H), 7.40–7.84 (m, 5H, Ar–H),
8.11 (s, 1H, CH-pyridazine), 8.54 (d, 2H, Ar–H); ms: m/z 336,
338 (M+); Anal. Cald for C18H13ClN4O: C, 64.19; H, 3.89; N,
58.66; H, 3.80; N, 19.14.
3-Chloro-6-(2-(4-chlorobenzylidene)hydrazinyl)-4-(p-tolyl)
16.64. Found: C, 64.18; H, 3.59; N, 16.50.
6-Chloro-3, 7-bis (4-methoxyphenyl)-[1,2,4]triazolo[4,3-b]
pyridazine (8g).
powder in 35% yield, mp 198–199°C; IR (potassium
bromide): (=C–H) 3068, (–C–H) 2957–2839 cmÀ1 1H nmr
This compound was obtained as a yellow
pyridazine (7o).
This compound was obtained as a yellow
powder in 40% yield, mp 201–202°C; IR (potassium bromide):
(NH) 3190, (N=CH) 1608 cmÀ1; H nmr (deuteriochloroform):
1
;
(deuteriochloroform): δ 3.90 (s, 6H, 2(OCH3)), 6.94–7.27 (m,
4H, Ar–H), 7.53 (d, 2H, Ar–H), 8.13 (s, 1H, CH-pyridazine),
8.50 (d, 2H, Ar–H); ms: m/z 366, 368 (M+); Anal. Cald for
C19H15ClN4O2: C, 62.21; H, 4.12; N, 15.25. Found: C,
δ 2.44 (s, 3H, CH3), 7.32 (d, 2H, Ar–H), 7.34 (d, 2H, Ar–H),
7.39 (s, 1H, N=CH), 7.49 (d, 2H, Ar–H), 7.78 (d, 2H, Ar–H),
8.13 (s, 1H, CH-pyridazine), 11.87 (br s, 1H, NH, D2O
exchangeable); ms: m/z 219 (M–N=CHC6H4Cl); Anal. Calcd
for C18H14Cl2N4: C, 60.52; H, 3.95; N, 15.68. Found: C,
60.22; H, 3.86; N, 15.70.
General procedure for preparation of 8a–o. A mixture of
appropriate hydrazones 7a–o (1.2 mmol) and nitrobenzene (7 mL)
was refluxed in an oil bath at 216°C for 20 h. Nitrobenzene was
removed under reduced pressure and the residue recrystallized
61.71; H, 4.19; N, 14.86.
6-Chloro-7-(4-methoxyphenyl)-3-(p-tolyl)-[1,2,4]triazolo[4,3-
b]pyridazine (8h). This compound was obtained as a yellow
powder in 57% yield, mp 187–188°C; IR (potassium bromide):
(=C–H) 3060–3025, (–C–H) 2994–2823 cmÀ1
;
1H nmr
(deuteriochloroform): δ 2.50 (s, 3H, CH3), 3.90 (s, 3H, OCH3),
7.11 (d, 2H, Ar–H), 7.40 (d, 2H, Ar–H), 7.63 (d, 2H, Ar–H),
8.1 (s, 1H, CH-pyridazine), 8.40 (d, 2H, Ar–H); ms: m/z 351,
353 (M+); Anal. Cald for C19H15ClN4O: C, 65.05; H, 4.31; N,
15.97. Found: C, 64.77; H, 4.12; N, 15.81.
in ethanol and methanol-ethyl acetate, respectively.
3,7-Diphenyl-[1,2,4]triazolo[4,3-b]pyridazine-6-ylchloro
(8a). This compound was obtained as a pale yellow powder in
90% yield, mp 155–156°C; IR (potassium bromide): (=C–H)
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet