Chemistry of Heterocyclic Compounds 2018, 54(12), 1145–1152
(3H, s, OCH3); 3.99 (3H, s, OCH3); 6.56 (1H, dd, J = 8.8,
90.6 (C-4); 91.7 (C-3'',5''); 125.3 (C-3',5'); 126.8 (С-1'');
127.1 (C-1'); 129.6 (C-2',6'); 138.0 (C-4'); 145.1 (C-3);
154.3 (C-2'',6''); 162.0 (С-4''); 163.3 (C-5). Found, %:
С 64.82; Н 5.78; N 15.76. C19H20N4O3. Calculated, %:
C 64.76; H 5.72; N 15.90.
J = 2.0, H-5''); 6.67 (1H, d, J = 2.0, H-3''); 6.74 (1H, s,
H-4); 7.22 (2H, d, J = 7.8, H-3',5'); 7.65 (1H, d, J = 8.8,
H-6''); 7.68 (2H, d, J = 7.8, H-2',6'); 8.64 (1Н, br. s, NH).
13C NMR spectrum, δ, ppm: 20.8 (CH3); 55.7 (OCH3); 56.1
(OCH3); 90.6 (С-4); 99.2 (С-3''); 106.3 (С-5''); 117.3
(С-6''); 125.2 (С-3',5'); 126.7 (С-1'); 129.5 (С-2',6'); 136.0
(С-4'); 137.9 (С-1''); 144.8 (С-3); 158.4 (С-2''); 163.4
(С-5); 163.6 (С-4''). Found, %: С 66.89; Н 5.55; N 17.27.
C18H18N4O2. Calculated, %: C 67.07; H 5.63; N 17.38.
5-[(2,4-Dimethoxyphenyl)diazenyl]-3-(4-methoxy-
phenyl)-1H-pyrazole (5с). Yield 285 mg (84%, method I),
220 mg (65%, method II), yellow powder, mp 131–132°С.
1H NMR spectrum, δ, ppm (J, Hz): 3.81 (3H, s, OCH3);
3.87 (3H, s, OCH3); 3.99 (3H, s, OCH3); 6.55 (1H, dd,
J = 8.8, J = 2.4, H-5''); 6.67 (1H, d, J = 2.4, H-3''); 6.73
(1H, s, H-4); 6.96 (2H, d, J = 8.3, H-3',5'); 7.66 (1H, d,
J = 8.8, H-6''); 7.72 (2H, d, J = 8.3, H-2',6'); 8.79 (1Н, br. s,
NH). 13C NMR spectrum, δ, ppm: 55.3 (OCH3); 55.7
(OCH3); 56.2 (OCH3); 90.1 (С-4); 99.2 (С-3''); 106.3
(С-5''); 114.4 (С-3',5'); 117.4 (С-6''); 122.1 (С-1'); 126.8
(С-2',6'); 136.1 (С-1''); 144.7 (С-3); 158.5 (С-4'); 159.5
(С-2''); 163.6 (С-4''); 164.5 (С-5). Found, %: С 63.74; Н 5.31;
N 16.61. C18H18N4O3. Calculated, %: C 63.89; H 5.36;
N 16.56.
3-(4-Methoxyphenyl)-5-[(2,4,6-trimethoxyphenyl)-
diazenyl]-1H-pyrazole (5g). Yield 327 mg (89%, method I),
260 mg (71%, method II), orange powder, mp 115–116°С.
1H NMR spectrum, δ, ppm (J, Hz): 3.82 (3H, s, OCH3);
3.85 (6H, s, OCH3); 3.89 (3H, s, OCH3); 6.31 (2H, s,
H-3'',5''); 6.67 (1H, s, H-4); 6.96 (2H, d, J = 8.5, H-3',5');
7.73 (2H, d, J = 8.5, H-2',6'); 9.78 (1Н, br. s, NH).
13C NMR spectrum, δ, ppm: 55.3 (OCH3); 55.6 (OCH3);
56.2 (2OCH3); 89.9 (C-4); 91.7 (C-3'',5''); 114.4 (C-3',5');
122.4 (С-1''); 126.7 (C-2',6'); 126.8 (C-1'); 144.8 (C-3);
154.1 (C-2'',6''); 159.4 (C-4'); 161.6 (С-4''); 163.6 (C-5).
Found, %: С 61.83; Н 5.55; N 15.09. C19H20N4O4.
Calculated, %: C 61.95; H 5.47; N 15.21.
3-(4-Chlorophenyl)-5-[(2,4,6-trimethoxyphenyl)diazen-
yl]-1H-pyrazole (5h). Yield 358 mg (96%, method I), 287 mg
1
(77%, method II), orange powder, mp 181–182°С. H NMR
spectrum, δ, ppm (J, Hz): 3.85 (6H, br. s, OCH3); 3.89 (3Н,
s, OCH3); 6.30 (2H, s, H-3'',5''); 6.80 (1H, s, H-4); 7.42 (2H,
d, J = 8.3, H-3',5'); 7.83 (2H, d, J = 8.3, H-2',6'); 9.64 (1Н,
br. s, NH). 13C NMR spectrum, δ, ppm: 55.7 (OCH3); 56.3
(2OCH3); 91.6 (C-4); 91.8 (C-3'',5''); 126.8 (С-1''); 127.1
(C-3',5'); 129.1 (C-2',6'); 129.3 (C-4'); 132.9 (C-1'); 144.9
(C-3); 154.5 (C-2'',6''); 162.2 (С-4''); 162.4 (C-5). Found,
%: С 57.96; Н 4.58; Cl 9.53; N 14.98. C18H17ClN4O3.
Calculated, %: C 57.99; H 4.60; Cl 9.51; N 15.03.
3-(4-Chlorophenyl)-5-[(2,4-dimethoxyphenyl)diazenyl]-
1H-pyrazole (5d). Yield 323 mg (94%, method I), 247 mg
(72%, method II), orange powder, mp 115–116°С.
1H NMR spectrum, δ, ppm (J, Hz): 3.88 (3H, s, OCH3);
3.97 (3H, s, OCH3); 6.65 (1H, dd, J = 8.8, J = 2.3, H-5'');
6.78 (1H, d, J = 2.3, H-3''); 6.93 (1H, s, H-4); 7.54 (2H, d,
J = 8.5, H-3',5'); 7.64 (1H, d, J = 8.8, H-6''); 7.91 (2H, d,
J = 8.5, H-2',6'); 10.35 (1Н, br. s, NH). 13C NMR spectrum,
δ, ppm: 55.8 (OCH3); 56.2 (OCH3); 91.8 (С-4); 99.2
(С-3''); 106.5 (С-5''); 117.5 (С-6''); 127.1 (С-3',5'); 129.0
(С-2',6'); 129.1 (С-4'); 133.0 (С-1'); 136.1 (С-1''); 144.6
(С-3); 158.7 (С-2''); 162.5 (С-5); 163.9 (С-4''). Found, %:
С 59.38; Н 4.21; Cl 10.42; N 16.53. C17H15ClN4O2.
Calculated, %: C 59.57; H 4.41; Cl 10.34; N 16.34.
3-Phenyl-5-[(2,4,6-trimethoxyphenyl)diazenyl]-1H-pyra-
zole (5e). Yield 322 mg (95%, method I), 281 mg (83%,
method II), orange powder, mp 164–165°С. 1H NMR
spectrum, δ, ppm (J, Hz): 3.84 (6H, s, OCH3); 3.88 (3H, s,
OCH3); 6.30 (2H, s, H-3'',5''); 6.75 (1H, s, H-4); 7.31–7.34
(1H, m, H-4'); 7.40–7.46 (2H, m, H-3',5'); 7.80 (2H, d,
J = 7.8, H-2',6'); 9.40 (1Н, br. s, NH). 13C NMR spectrum,
δ, ppm: 55.8 (OCH3); 56.3 (2OCH3); 91.1 (C-4); 91.8
(C-3'',5''); 125.4 (C-3',5'); 126.8 (С-1''); 128.5 (C-4'); 129.1
(C-2',6'); 130.0 (C-1'); 145.3 (C-3); 154.4 (C-2'',6''); 162.1
(С-4''); 163.2 (C-5). Found, %: С 63.74; Н 5.31; N 16.62.
C18H18N4O3. Calculated, %: C 63.89; H 5.36; N 16.56.
3-(p-Tolyl)-5-[(2,4,6-trimethoxyphenyl)diazenyl]-1H-
pyrazole (5f). Yield 345 mg (98%, method I), 256 mg
(73%, method II), orange-red powder, mp 199–200°С.
1H NMR spectrum, δ, ppm (J, Hz): 2.37 (3H, s, CH3); 3.83
(6Н, s, OCH3); 3.88 (3H, s, OCH3); 6.31 (2H, s, H-3'',5'');
6.70 (1H, s, H-4); 7.23 (2H, d, J = 7.5, H-3',5'); 7.68 (2H,
d, J = 7.5, H-2',6'); 9.32 (1Н, br. s, NH). 13C NMR
spectrum, δ, ppm: 20.9 (CH3); 55.7 (OCH3); 56.3 (2OCH3);
Synthesis of 2-arylpyrazolo[5,1-c][1,2,4]benzotriazines
6a–h (General method). Azo compound 5a–h (1 mmol) was
dissolved in glacial АсОН (5 ml), then p-TsOH (17 mg,
10 mol %) was added. The reaction mixture was stirred at
80–90°С until the disappearance of the starting azo
compound 5a–h (3–8 h, control by TLC). The solution was
concentrated to two thirds of the volume by evaporation at
reduced pressure, and the reaction mixture was cooled. The
precipitate that formed was filtered off, recrystallized from
EtOH, and dried.
8-Methoxy-2-phenylpyrazolo[5,1-c][1,2,4]benzotriazine
(6a). Yield 218 mg (79%), orange powder, mp 206–207°С.
1H NMR spectrum, δ, ppm (J, Hz): 4.03 (3H, s, ОCH3);
7.29 (1H, dd, J = 9.1, J = 2.5, Н-7); 7.42–7.46 (1Н, m,
H-4'); 7.49–7.52 (2H, m, H-3',5'); 7.63 (1H, d, J = 2.5,
H-9); 7.83 (1H, s, Н-3); 8.11 (2H, d, J = 7.3, H-2',6'); 8.39
(1Н, d, J = 9.1, H-6). 13C NMR spectrum, δ, ppm: 56.6
(OCH3); 94.2 (C-9); 97.8 (C-3); 117.6 (C-7); 126.4
(C-3',5'); 127.2 (C-5a); 128.9 (C-2',6'); 129.3 (C-1'); 131.6
(C-4'); 132.3 (C-6); 133.9 (C-9a); 147.2 (C-3a); 154.0
(C-2); 164.4 (C-8). Found, %: С 69.58; Н 4.42; N 20.25.
С16Н12N4O. Calculated, %: С 69.55; Н 4.38; N 20.28.
8-Methoxy-2-(p-tolyl)pyrazolo[5,1-c][1,2,4]benzotri-
azine (6b). Yield 273 mg (94%), red-brown powder, mp 189–
1
190°С. H NMR spectrum, δ, ppm (J, Hz): 2.42 (3H, s,
CH3); 4.12 (3H, s, OCH3); 7.31 (2H, d, J = 8.0, H-3',5');
7.34 (1H, dd, J = 9.1, J = 2.4, H-7); 7.74 (1H, s, Н-3); 7.78
(1H, d, J = 2.4, H-9); 8.03 (2H, d, J = 8.0, H-2',6'); 8.46
(1Н, d, J = 9.1, H-6). 13C NMR spectrum, δ, ppm: 21.0
1150