ꢂꢁꢁꢁ
E. Şahan et al.: 4-Benzoyl-1,5-diphenyl-1H-pyrazole-3-carboxylic acid derivativesꢀ
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(N-H), 2959 (aliph. C-H), 1670, 1650 cm-1 (C=O); 1H NMR: δ 3.00 (s, 6H,
CH3) 7.12–7.90 (m, 15H, ArH), 9.30 (s, 1H, NH); 13C NMR: δ 46.6, 122.1,
125.4, 127.7, 128.3, 128.5, 128.6, 129.1, 129.4, 129.5, 129.8, 133.2, 137.8,
138.6, 143.4, 144.2, 158.7, 191.3. Anal. Calcd for C25H22N4O2: C, 73.15; H,
5.40; N, 13.65. Found: C, 72.80; H, 5.67; N, 13.96.
was slightly effective against Mycobacterium smegmatis
among the tested microorganisms.
The strongest activity was displayed by compound 3a.
4-Benzoyl-1,5-diphenyl-3-[(N′,N′-diphenylhydrazino)
carbonyl]-1H-pyrazole (3b)ꢀWhite powder; mp 207–208°C; IR: υ
3284 (N-H), 1686, 1662 cm-1 (C=O); 1H NMR: δ 7.00–7.90 (m, 25H, ArH),
9.18 (s, 1H, NH); 13C NMR: δ 119.7, 120.2, 120.4, 122.4, 123.0, 125.4, 127.8,
128.2, 128.5, 128.6, 128.9, 129.1, 129.1, 129.3, 129.5, 129.9, 133.1, 138.0,
138.8, 144.1, 144.2, 145.9, 159.7, 191.2. Anal. Calcd for C35H26N4O2: C,
78.63; H, 5.90; N, 10.48. Found: C, 78.54; H, 5.43; N, 10.73.
Experimental
Solvents were dried by heating under reflux with appropriate drying
agents and distilled before use. Melting points were determined on
an Electrothermal 9200 apparatus and are uncorrected. Microanaly-
ses were performed on a Carlo Erba Elemental Analyzer, model 1108.
The IR spectra were recorded on a Shimadzu Model 8400 FT IR spec-
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trophometer. The H NMR spectra (400 MHz) and 13C NMR spectra
4-Benzoyl-1,5-diphenyl-3-{N′-[(4-methylphenyl)hydrazino]
carbonyl}-1H-pyrazole (3c)ꢀWhite powder; mp 175–176°C; IR: υ
(100 MHz) were recorded on a Bruker-400 Ultra Shield instrument.
All experiments were followed by TLC using a DC Alufolien Kieselgel
60 F254 Merck and Camag TLC lamp (254/366 nm).
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3269 (N-H), 2920 (aliph. C-H), 1678, 1662 cm-1 (C=O); H NMR: δ 3.02
(s, 3H, CH3) 6.70–7.85 (m, 20H, ArH), 8.75 (s, 1H, NH); 13C NMR: δ 40.8,
113.1, 113.4, 119.7, 122.3, 125.4, 127.9, 128.2, 128.5, 128.5, 128.6, 129.0,
129.1, 129.3, 129.5, 129.9, 133.1, 138.0, 138.8, 144.1, 144.3, 149.3, 159.5,
191.4. Anal. Calcd for C30H24N4O2: C, 76.25; H, 5.12; N, 11.86. Found: C,
76.05; H, 5.65; N, 11.30.
Antimicrobial assay
Bacterial strains used in the present study were obtained from the
Department of Biology, Faculty of Science, Erciyes University, Kay-
seri, Turkey. The bacterial strains were Aeromonas hydrophila ATCC
7965, Bacillus brevis FMC 3, Bacillus cereus RSKK 863, Bacillus subtilis
ATCC 6633, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC
27736, Morganella morganii, Mycobacterium smegmatis RUT, Proteus
mirabilis BC 3624, Pseudomonas aeruginosa ATCC 27853, Salmonella
typhimurium NRRLE 4463, Staphylococcus aureus ATCC 29213 and
Yersinia enterocolitica ATCC 1501. The yeasts were Candida albicans
ATCC 1223 and Saccharomyces cerevisiae BC 5461 (Table 1). Antimi-
crobial activity testing was carried out by disc diffusion methods
[21] using 100 μL of suspension containing 106–107 colony forming
units (cfu)/mL of bacteria and yeasts spread on nutrient agar (NA)
and sabouraud dextrose agar (SDA). The sterile discs (6 mm) were
impregnated with 10 μL of compounds in dimethyl sulfoxide (DMSO;
500 mg/disc) placed in the middle of inoculated agar plates. DMSO
was added on the disc to provide negative control. Ampicillin (AMP,
10 μg) and chloramphenicol (C, 30 μg) were used as positive con-
trols. Yeasts C. albicans and S. cerevisiae were incubated at 25°C for
24–48 h in the inverted position. Other microorganisms were incu-
bated at 37°C for 18–24 h. At the end of the period, antimicrobial ac-
tivity was evaluated by measuring the zone of inhibition (mm), and
experiments were repeated twice.
General procedure for 4a–c
A mixture of acid chloride 1 (0.40 g) anhydrous AlCl3 (0.70 g) and an
aromatic compound (molar ratio 1:5:25) was heated at 100–140°C for
1–3 h in a calcium chloride guard tube fitted round bottom flask of
50 mL. Then, the mixture was poured onto HCl/ice-water for hydroly-
sis and extracted with diethyl ether. Then, petroleum ether was added
and the resulting solid was collected and crystallized from ethanol.
4-Benzoyl-1,5-diphenyl-3-(4-methylbenzoyl)-1H-pyrazole
(4a)ꢀCompound 4a was prepared from toluene with heating for 1 h
at 120°C; yield 61% (0.28 g); white powder; mp 192–193°C; IR: υ 1666,
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1639 cm-1 (C=O); H NMR: δ 2.45 (s, 3H, CH3), 7.25–8.30 (m, 19H, Ar-
H); 13C NMR: δ 21.7, 124.2, 125.4, 128.1, 128.3, 128.4, 128.5, 128.9, 129.0,
129.2, 129.9, 130.7, 132.9, 134.0, 138.1, 139.1, 143.3, 143.9, 150.2, 186.4,
191.5. Anal. Calcd for C30H22N2O2: C, 81.43; H, 5.01; N, 6.33. Found: C,
81.18; H, 5.00; N, 5.99.
4-Benzoyl-1,5-diphenyl-3-(4-chlorobenzoyl)-1H-pyrazole
(4b)ꢀCompound 4b was prepared from chlorobenzene with heating
for 2 h at 100°C; yield 42% (0.20 g); white powder; mp 180–181°C;
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IR: υ 1666, 1639 cm-1 (C=O); H NMR: δ 7.20–8.35 (m, 19H, Ar-H); 13C
NMR: δ 124.4, 125.4, 127.8, 128.4, 128.5, 129.1, 129.2, 129.3, 129.9, 132.1,
133.1, 134.8, 137.3, 139.0, 139.6, 143.4, 149.6, 185.3, 191.4. Anal. Calcd for
C29H19N2O2Cl: C, 75.24; H, 4.14; N, 6.05. Found: C, 75.28; H, 4.17; N, 5.57.
General procedure for 3a–c
A solution of acid chloride 1 (0.20 g), N,N-disubstituted hydrazine
2a–c (0.04 mL) (molar ratio 1:1) and a catalytic amount of pyridine in
xylene was heated under reflux for 2 h. Then the solvent was removed
and the remaining oily residue was treated with dry diethyl ether and
the mixture was stirred for 1 h. The resultant solid product 3 was crys-
tallized from toluene or cyclohexane and dried over P2O5.
4-Benzoyl-1,5-diphenyl-3-(4-bromobenzoyl)-1H-pyrazole
(4c)ꢀCompound 4c was prepared from bromobenzene with heating
for 2 h at 140°C; yield 56% (0.28 g); white powder; mp 172–173°C; IR:
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υ 1660, 1649 cm-1 (C=O); H NMR: δ 7.25–8.30 (m, 19H, Ar-H); 13C NMR:
δ 124.4, 125.4, 125.4, 127.8, 127.9, 128.2, 128.4, 128.4, 128.4, 128.5, 128.6,
129.1, 129.1, 129.2, 129.3, 129.4, 129.8, 129.9, 130.6, 131.6, 132.2, 133.0, 133.1,
135.2, 136.5, 137.9, 138.1, 138.9, 143.5, 149.6, 185.5, 191.4. Anal. Calcd for
C29H19N2O2Br: C, 68.65; H, 3.77; N, 5.52. Found: C, 68.27; H, 4.12; N, 5.37.
4-Benzoyl-3-[(N′,N′-dimethylhydrazino)carbonyl]-1,5-diphe-
nyl-1H-pyrazole (3a)ꢀWhite powder; mp 148–149°C; IR: υ 3209
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