496
A. Hanzlowsky, B. Jelencˇicˇ, S. Recˇnik, J. Svete, A. Golobicˇ and B. Stanovnik
Vol. 40
1
Diethyl 1-(1,2,4-Triazolo[4,3–b]pyridazin-6-yl)-1H-pyrazole-
4,5-dicarboxylate (11g).
3123 (N–H), 1737, 1731 (C=O). H nmr (deuteriochloroform): δ
1.37 and 1.42 (6H, 2t, 1:1, J = 7.2 Hz, 2 x CH CH ); 4.34 and
3
2
4.45 (4H, 2q, 1:1, J = 7.2 Hz, 2 x CH CH ); 8.09 (1H, s, 3–H);
11.31 (1H, br s, 1–H). C nmr (deuteriochloroform): δ 14.2,
14.3, 60.9, 61.9, 115.1, 136.2, 141.4, 161.6, 162.0.
2
3
This compound was prepared from 4 and 6-hydrazino-1,2,4-
triazolo[4,3–b]pyridazine (5g) (0.150 g, 1 mmole); stirring at
room temperature for 10 h. Yield: 0.145 g (44%); mp 124–125°
13
–1
1
(from ethanol). Ir (cm ): 1745, 1731 (C=O). H nmr (deuteri-
Diethyl 1-Phenyl-1H-pyrazole-4,5-dicarboxylate (11b).
ochloroform): δ 1.38 and 1.46 (6H, 2t, 1:1, J = 7.2 Hz, 2 x
This compound was prepared from 4 and phenylhydrazine
monohydrochloride (5a) (0.145 g, 1 mmole); stirring at room
CH CH ); 4.36 and 4.55 (4H, 2q, 1:1, J = 7.2 Hz, CH CH ); 8.02
3
2
2
3
(1H, d, J = 10.2 Hz, 7'–H); 8.14 (1H, s, 3–H); 8.30 (1H, dd, J =
–1
temperature for 6 h. Yield: 0.247 g (86%); oil. Ir (cm ): 1741,
13
0.8, 10.2 Hz, 8'–H); 8.96 (1H, d, J = 0.8 Hz, 3'–H). C nmr (deu-
1
1722 (C=O). H nmr (deuteriochloroform): δ 1.23 and 1.35 (6H,
teriochloroform): δ 14.4, 14.5, 61.7, 63.5, 116.2, 118.1, 127.6,
138.8, 143.4, 143.5, 149.0, 160.8, 161.2.
2t, 1:1, J = 7.2 Hz, 2 x CH CH ); 4.33 and 4.34 (4H, 2q, 1:1, J =
3
2
7.2 Hz, 2 x CH CH ); 7.39–7.53 (5H, m, Ph); 8.05 (1H, s, 3–H).
2
3
Anal. Calcd. for C
H N O (330.30): C, 50.91; H, 4.27; N,
13
14 14 6 4
C nmr (deuteriochloroform): δ 14.1, 14.6, 61.2, 63.1, 124.4,
25.44. Found: C, 50.95; H, 4.41; N, 25.68. Hrms Calcd. for
N O : 330.107653. Found: 330.107050.
129.4, 129.7, 137.4, 139.4, 141.7, 161.2, 162.1. Ir and nmr data
are in agreement with the literature [28] data.
C
H
14 14
6 4
Hrms Calcd. for C
288.111960.
H N O : 288.111007. Found:
15 16 2 4
Diethyl 1-(Tetrazolo[1,5–b]pyridazin-6-yl)-1H-pyrazole-4,5-
dicarboxylate (11h).
Diethyl 1-(4-Nitrophenyl)-1H-pyrazole-4,5-dicarboxylate (11c).
This compound was prepared from 4 and 6-hydrazinotetra-
zolo[1,5–b]pyridazine (5h) (0.151 g, 1 mmole); stirring at room
temperature for 24 h. Yield: 0.250 g (70%); mp 141–143° (from
This compound was prepared from 4 and 4-nitrophenylhy-
drazine (5c) (0.153 g, 1 mmole); stirring at room temperature for
24 h. Yield: 0.120 g (36%); mp 70–73° (from ethanol), lit [28] mp
–1
1
ethanol). Ir (cm ): 1744, 1728 (C=O). H nmr (deuteriochloro-
form): δ 1.38 and 1.53 (6H, 2t, 1:1, J = 7.2 Hz, 2 x CH CH );
–1
1
3
2
73–75°. Ir (cm ): 1741, 1720 (C=O). H nmr (deuteriochloro-
form): δ 1.32 and 1.36 (6H, 2t, 1:1, J = 7.2 Hz, 2 x CH CH ); 4.35
4.37 and 4.65 (4H, 2q, 1:1, J = 7.2 Hz, 2 x CH CH ); 8.19 (1H, s,
2
3
3
2
3–H); 8.41 (1H, d, J = 9.8 Hz, 7'–H); 8.55 (1H, d, J = 9.8 Hz,
and 4.40 (4H, 2q, 1:1, J = 7.2 Hz, 2 x CH CH ); 7.23 (2H, dt, J =
2
3
13
8'–H). C nmr (deuteriochloroform): δ 14.0, 14.2, 61.6, 63.8,
2.5, 9.0 Hz, 2H of Ar); 8.09 (1H, s, 3–H); 8.35 (2H, dt, J = 2.5, 9.0
13
118.2, 119.6, 127.2, 137.6, 142.3, 143.9, 149.3, 160.3, 160.6.
Hz, 2H of Ar). C nmr (deuteriochloroform): δ 14.2, 14.6, 61.5,
Anal. Calcd. for C
H N O (331.29): C, 47.13; H, 3.96; N,
63.6, 117.6, 124.5, 125.3, 137.4, 142.7, 144.0, 147.7, 160.9,
161.7.
13 13 7 4
29.60. Found: C, 46.80; H, 4.24; N, 29.57.
Anal. Calcd. for C
12.61. Found: C, 53.93; H, 4.53; N, 12.75.
H N O (333.30): C, 54.05; H, 4.54; N,
15 15 3 6
Diethyl 1-(Pyrimidin-2-yl)-1H-pyrazole-4,5-dicarboxylate (11i).
This compound was prepared from 4 and 2-hydrazinopyrimi-
dine (5i) (0.110 g, 1 mmole); stirring at room temperature for 4 h.
Diethyl 1-(6-Chloropyridazin-3-yl)-1H-pyrazole-4,5-dicarboxy-
late (11d).
–1
Yield: 0.258 g (89%); mp 73–75° (from ethanol). Ir (cm ): 1730,
1
1721 (C=O). H nmr (deuteriochloroform): δ 1.36 and 1.42 (6H,
This compound was prepared from 4 and 6-chloro-3-
hydrazinopyridazine (5d) (0.145 g, 1 mmole); stirring at room
temperature for 8 h. Yield: 0.093 g (29%); mp 95–99° (from
2t, 1:1, J = 7.2 Hz, 2 x CH CH ); 4.34 and 4.51 (4H, 2q, 1:1, J =
3
2
7.2 Hz, 2 x CH CH ); 7.31 (1H, t, J = 4.9 Hz, 5'–H); 8.14 (1H, s,
2
3
13
–1
1
3–H); 8.77 (2H, d, J = 4.9 Hz, 4'–H, 6'–H). C nmr (deuteri-
ochloroform): δ 13.9, 14.2, 61.0, 62.7, 116.6, 120.0, 138.2, 142.9,
155.2, 158.8, 161.3, 161.4.
ethanol). Ir (cm ): 1748, 1719 (C=O). H nmr (deuteriochloro-
form): δ 1.36 and 1.43 (6H, 2t, 1:1, J = 7.2 Hz, CH CH ); 4.35
3
2
and 4.55 (4H, 2q, 1:1, J = 7.2 Hz, CH CH ); 7.68 (1H, d, J = 9.0
Hz, 5'–H); 8.12 (1H, s, 3–H); 8.17 (1H, d, J = 9.4 Hz, 4'–H).
nmr (deuteriochloroform): δ 14.2, 14.5, 61.5, 63.5, 117.4, 121.8,
2
3
13
Anal. Calcd. for C
H N O (290.27): C, 53.79; H, 4.86; N,
C
13 14 4 4
19.30. Found: C, 53.95; H, 5.04; N, 19.45.
131.2, 137.4, 143.5, 153.7, 156.2, 161.2, 161.5.
Diethyl 1-(6-Phenylpyridazin-3-yl)-1H-pyrazole-4,5-dicarboxy-
late (11e).
Anal. Calcd. for C
H ClN O (324.72): C, 48.08; H, 4.04;
13 13 4 4
N, 17.25. Found: C, 48.36; H, 3.99; N, 17.26.
A mixture of 4 (0.243 g, 1 mmole), 3-hydrazino-6-phenylpyri-
dazine (5e) (0.186 g, 1 mmole), ethanol (5 ml), and hydrochloric
acid (37%, 0.1 ml, ~1 mmole) was stirred at room temperature
for 24 h. The precipitate was collected by filtration and washed
with ethanol to give 11e. Yield: 0.134 g (37%); mp 110–112°
Diethyl 1-(Imidazo[1,2–b]pyridazin-6-yl)-1H-pyrazole-4,5-
dicarboxylate (11f).
This compound was prepared from 4 and 6-hydrazinoimi-
dazo[1,2–b]pyridazine (5f) (0.149 g, 1 mmole); stirring at room
temperature for 24 h. Yield: 0.160 g (49%); mp 91–94° (from
–1
1
(from ethanol). Ir (cm ): 1742, 1724 (C=O). H nmr (deuteri-
ochloroform): δ 1.37 and 1.45 (6H, 2t, 1:1, J = 7.2 Hz, 2 x
CH CH ); 4.36 and 4.59 (4H, 2q, 1:1, J = 7.2 Hz, 2 x CH CH );
–1
1
ethanol). Ir (cm ): 1761, 1724 (C=O). H nmr (deuteriochloro-
form): δ 1.37 and 1.43 (6H, 2t, 1:1, J = 7.2 Hz, 2 x CH CH );
3
2
2
3
3
2
7.51–7.58 (3H, m, 3H of Ph); 8.02 (1H, d, J = 9.4 Hz, 5'–H);
8.05–8.09 (2H, m, 2H of Ph); 8.14 (1H, s, 3–H); 8.21 (1H, d, J =
9.0 Hz, 4'–H). C nmr (deuteriochloroform): δ 14.3, 14.6, 61.4,
4.35 and 4.53 (4H, 2q, 1:1, J = 7.2 Hz, 2 x CH CH ); 7.83 (2H, br
2
3
s, 2'–H and 3'–H); 7.83 (1H, d, J = 9.8 Hz, 7'–H); 8.10 (1H, s,
13
13
3–H); 8.11 (1H, d, J = 9.8 Hz, 8'–H). C nmr (deuteriochloro-
63.4, 117.0, 119.8, 127.0, 127.6, 129.5, 130.8, 135.8, 137.1,
143.2, 153.3, 159.7, 161.5, 161.7.
form): δ 14.4, 14.6, 61.5, 63.2, 111.9, 117.2, 117.3, 128.3, 135.6,
136.9, 138.1, 142.8, 147.4, 161.2, 161.5.
Anal. Calcd. for C
H N O (366.37): C, 62.29; H, 4.95; N,
Anal. Calcd. for C
H N O (329.31): C, 54.71; H, 4.59; N,
19 18 4 4
15 15 5 4
15.29. Found: C, 62.36; H, 4.86; N, 15.52.
21.27. Found: C, 55.01; H, 4.39; N, 21.44.