SYNTHESIS AND REACTIONS OF 3-(3-ETHOXYCARBONYL-1-PHENYL-1H-PYRAZOL-4-YL)PROPENIC...
717
boxylate (XIIIc). Yield 67%, mp 149–151°C. 1H NMR
spectrum, δ, ppm: 1.44 t (3H, CH3, J 7.2 Hz), 4.42 q (2H,
CH2O, J 7.2 Hz), 7.36 d (1H, CH=, J 16.4 Hz), 7.40 t
(1H, Ph, J 7.2 Hz), 7.53–7.68 m (5H, Ph + C6H4), 7.94 d
(2H, Ph, J 8.0 Hz), 8.02–8.07 m (2H, CH= + C6H4), 9.35
s (1H, pyrazole). Found, %: C 62.94; H 4.00; N 13.12.
C22H17ClN4O3. Calculated, %: C 62.79; H 4.07; N 13.31.
phenyl-1H-pyrazole-3-carboxylate (XId). Yield 67%,
mp 220–221°C. 1H NMR spectrum, δ, ppm: 1.45 t (3H,
CH3CH2, J 7.2 Hz), 2.40 C (3H, CH3), 4.40 q (2H,
CH2O, J 7.2 Hz), 6.54 C (1H, H4 Fu), 7.39 t (1H, Ph,
J 7.2 Hz), 7.53 t (2H, Ph, J 8.0 Hz), 7.64 d (1H, CH=,
J 16.4 Hz), 7.77 br.s (1H, H5 Fu), 7.81 d (1H, CH=,
J 16.4 Hz), 7.90 d (2H, Ph, J 8.0 Hz), 9.32 s (1H,
pyrazole). Found, %: C 58.96; H 3.97; N 18.98.
C22H18N6O3S. Calculated, %: C 59.18; H 4.06; N 18.82.
Ethyl1-phenyl-4-{(E)-2-[5-(4-chlorophenyl)-
1,3,4-oxadiazol-2-yl]ethenyl}-1H-pyrazole-3-car-
boxylate (XIIId). Yield 70%, mp 264–265°C. 1H NMR
spectrum, δ, ppm: 1.46 t (3H, CH3, J 7.2 Hz), 4.43 q (2H,
CH2O, J 7.2 Hz), 7.34 d (1H, CH=, J 16.4 Hz), 7.40 t
(1H, Ph, J 7.6 Hz), 7.56 t (2H, Ph, J 7.8 Hz), 7.63 d (2H,
C6H4, J 8.0 Hz), 7.94 d (2H, Ph, J 8.0 Hz), 8.03–8.08 m
(3H, CH= + C6H4), 9.35 s (1H, pyrazole). Found, %:
C 62.91; H 3.95; N 13.48. C22H17ClN4O3. Calculated,
%: C 62.79; H 4.07; N 13.31.
Ethyl 4-[(E)-2-{3-(2-methyl-3-furyl)[1,2,4]-
triazolo[3,4-b][1,3,4]thiadiazol-6-yl}ethenyl]-1-
phenyl-1H-pyrazole-3-carboxylate (XIe). Yield 71%,
mp 241–242°C. 1H NMR spectrum, δ, ppm: 1.45 t (3H,
CH3CH2, J 7.2 Hz), 2.69 s (3H, CH3), 4.41 q (2H, CH2O,
J 7.2 Hz), 7.02 s (1H, H4 Fu), 7.40 t (1H, Ph, J 7.2 Hz),
7.54 t (2H, Ph, J 8.0 Hz), 7.58 d (1H, CH=, J 16.4 Hz),
7.61 s (1H, H5 Fu), 7.87 d (1H, CH=, J 16.4 Hz), 7.91 d
(2H, Ph, J 8.0 Hz), 9.35 s (1H, pyrazole). Found, %:
C 58.90; H 4.00; N 18.61. C22H18N6O3S. Calculated, %:
C 59.18; H 4.06; N 18.82.
4-[(E)-2-(5-Aryl-1,3,4-oxadiazol-2-yl)ethenyl]-1-
phenyl-1H-pyrazole-3-carboxylic acids XIVa, XIVb.
To a solution of 5 mmol of ester XIIIa, XIIId in 20 ml of
dioxane was added a solution of 0.34 g (6 mmol) of KOH
in 3 ml of ethanol. The mixture was boiled for 30 min,
then poured in 40 ml of water and acidified with 18%
hydrochloric acid till pH 3 (~1.5 ml). The precipitate was
filter-ed off and crystallized from a mixture ethanol–DMF,
3:1.
Ethyl 4-[(E)-2-(5-aryl-1,3,4-oxadiazol-2-yl)-
ethenyl]-1-phenyl-1H-pyrazole-3-carboxylates XIIIa–
XIIId.Amixture of 1.00 g (3.3 mmol) of acid chloride III,
3.3 mmol of aryltetrazole XIIa–XIId, and 3 ml of pyridine
was boiled till the end of nitrogen evolution (~ 2 h). Then
15 ml of water was added, and the mixture was ground
till a precipitate formed. The latter was filtered off and
crystallized from DMF.
1-Phenyl-4-[(E)-2-(5-phenyl-1,3,4-oxadiazol-2-
yl)ethenyl]-1H-pyrazole-3-carboxylic acid (XIVa).
Yield 87%, mp 262–264°C. 1H NMR spectrum, δ, ppm:
7.31 d (1H, CH=, J 16.4 Hz), 7.39 t (1H, Ph, J 7.2 Hz),
7.55 t (2H, Ph, J 8.0 Hz), 7.58–7.63 m (3H, Ph), 7.94 d
(2H, Ph, J 7.6 Hz), 8.04–8.10 m (3H, CH= + Ph), 9.30 s
(1H, pyrazole), 13.05 br.s (1H, COOH). Found, %:
C 66.81; H 3.99; N 15.85. C20H14N4O3. Calculated, %:
C 67.03; H 3.94; N 15.63.
Ethyl 1-phenyl-4-[(E)-2-(5-phenyl-1,3,4-oxadi-
azol-2-yl)ethenyl]-1H-pyrazole-3-carboxylate
(XIIIa). Yield 78%, mp 228–229°C. 1H NMR spectrum,
δ, ppm: 1.46 t (3H, CH3, J 7.2 Hz), 4.42 q (2H, CH2O,
J 7.2 Hz), 7.33 d (1H, CH=, J 16.4 Hz), 7.41 t (1H, Ph,
J 7.2 Hz), 7.53–7.61 m (5H, Ph), 7.94 d (2H, Ph,
J 8.0 Hz), 8.00–8.08 m (3H, CH= + Ph), 9.34 s (1H,
pyrazole). Found, %: C 68.12; H 4.81; N 14.31.
C22H18N4O3. Calculated, %: C 68.38; H 4.70; N 14.50.
1-Phenyl-4-{(E)-2-[5-(4-chlorophenyl)-1,3,4-
oxadiazol-2-yl]ethenyl}-1H-pyrazole-3-carboxylic
acid (XIVb). Yield 71%, mp > 300°C. 1H NMR spectrum,
δ, ppm: 7.31 d (1H, CH=, J 16.4 Hz), 7.40 t (1H, Ph,
J 7.2 Hz), 7.54 t (2H, Ph, J 8.0 Hz), 7.62 d (2H, C6H4,
J 8.4 Hz), 7.93 d (2H, Ph, J 8.0 Hz), 8.03–8.09 m (3H,
CH= + C6H4), 9.29 s (1H, pyrazole), 13.10 br.s (1H,
COOH). Found, %: C 60.94; H 3.42; N 14.14.
C20H13ClN4O3. Calculated, %: C 61.16; H 3.34; N 14.26.
Ethyl 4-{(E)-2-[5-(4-methylphenyl)-1,3,4-oxadi-
azol-2-yl]ethenyl}-1-phenyl-1H-pyrazole-3-carboxy-
1
late (XIIIb). Yield: 72%, mp 246–248°C. H NMR
spectrum, δ, ppm: 1.46 t (3H, CH3CH2, J 7.2 Hz), 2.46 C
(3H, CH3), 4.43 q (2H, CH2O, J 7.2 Hz), 7.32 d (1H,
CH=, J 16.4 Hz), 7.38–7.44 m (3H, Ph + C6H4), 7.41 t
(2H, Ph, J 8.0 Hz), 7.94 d (4H, Ar, J 8.0 Hz), 8.03 d (1H,
CH=, J 16.4 Hz), 9.34 C (1H, pyrazole). Found, %:
C 68.61; H 4.95; N 14.21. C23H20N4O3. Calculated, %:
C 68.99; H 5.03; N 13.99.
REFERENCES
1. Yokoyama,Y., Kurimoto,Y., Saito,Y., Katsurada, M., Okada,
I., OsanoY.T., Sasaki, C., Yokoyama, Y., Tukada, H., Ada-
Ethyl 1-phenyl-4-{(E)-2-[5-(2-chlorophenyl)-
1,3,4-oxadiazol-2-yl]ethenyl}-1H-pyrazole-3-car-
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 5 2009