Evaluation of diethyl 6,6'-(1,4-phenylene)bis(4-aryl-2-oxo-cyclohex-3-enecarboxylates) 499
points are taken in open capillaries and are uncorrected.
Bis cyclohexenone ester 17: IR (KBr) ν (cm−1): 3052,
2980, 2927, 1665, 1738, 1609, 825, 679; 1H NMR (δ ppm),
(J Hz): 0.92 (6H, t, CH2CH3 at C-1, J=7.0), 2.97-2.93 (2H,
H5a, m), 3.07–3.00 (2H, H5a, m), 3.66–3.63 (1H, H6, m),
3.93–3.87 (4H, m, CH2CH3 at C-1), 4.11 (1H, H1, d, J=15.6),
6.56 (1H, d, H3, J=2.0), 7.76–7.38 (12H, m, Harom.); 13C NMR
(δ ppm): 13.79 CH2CH3 at C-1, 35.20 C-5, 43.35 C-6, 59.91
CH2CH3 at C-1, 58.60 C-1, 123.28 C-3, 157.89 C-4, 169.09
C=O at C-1, 194.21 C-2, 129.78–127.61 -Carom., 140.22,
136.17, 135.14 ipso-C’s.
IR spectra are recorded in KBr (pellet forms) on a ermo
Nicolet-Avatar-330 FT-IR spectrophotometer and impor-
tant absorption values (cm−1) alone are listed. 1H and 13
C
NMR spectra are recorded at 400 and 100MHz, respec-
tively, on Bruker Avance II 400 NMR spectrometer using
DMSO-d6 as solvent. Two-dimensional HOMOCOR and
HSQC spectra are recorded at Bruker DRX 500 NMR
spectrometer. e ESI +ve MS spectra are recorded on
a Bruker Daltonics LC-MS spectrometer. Satisfactory
microanalysis data are obtained on Carlo Erba 1106 CHN
analyzer.
Bis cyclohexenone ester 18: IR (KBr) ν (cm−1): 3063,
1
2974, 2923, 2849, 1664, 1737, 1607, 825, 756; H NMR (δ
By adopting the literature precedent24, bis chalcone
derivatives 8–13 are prepared.
ppm), (J Hz): 0.85–0.97 (6H, m, CH2CH3 at C-1), 2.99–2.92
(2H, H5a, m), 3.08–3.00 (2H, H5a, m), 3.68–3.56 (1H, H6,
m), 3.94–3.86 (4H, m, CH2CH3 at C-1), 4.03 (1H, H1, d,
J=14.5), 6.58 (1H, d, H3, J=3.0), 7.67–7.28 (12H, m, Harom.);
13C NMR (δ ppm): 14.31 CH2CH3 at C-1, 35.44 C-5, 43.90
C-6, 60.51 CH2CH3 at C-1, 59.22 C-1, 123.78 C-3, 158.41
General procedure for the synthesis of bis
cyclohexenone ester derivatives 14–19
To a solution of sodium ethoxide (0.001 mol) in 30 ml
of absolute ethanol, freshly distilled ethyl acetoacetate
(0.01 mol) and respective bis chalcones 8–13 (0.01 mol)
in absolute ethanol (40 ml) was mixed. is mixture was
refluxed in a water bath for 3–6h by maintaining the
temperature around (70–80°C). e reaction mixture was
allowed to cool and filtered. en the crude product was
recrystallized from absolute ethanol to afford bis cyclo-
hexenone ester derivatives 14–19.
C-4, 169.82 C=O at C-1, 194.59 C-2, 128.23–124.46 -Carom.
,
137.04, 132.22, 129.07 ipso-C’s.
Bis cyclohexenone ester 19: IR (KBr) ν (cm−1): 3030,
1
2958, 2924, 2850, 1653, 1737, 1601, 831, 756; H NMR (δ
ppm), (J Hz): 0.94 (6H, m, CH2CH3 at C-1, J=7.2), 3.02–2.94
(2H, H5a, m), 3.09–3.03 (2H, H5a, m), 3.64–3.60 (1H, H6,
m), 3.81 (6H, s, OCH3 at phenyl rings), 3.92–3.90 (4H, m,
CH2CH3 at C-1), 4.06 (1H, H1, d, J=14.5), 6.51 (1H, d, H3,
J=1.5), 7.71–6.99 (12H, m, Harom.); 13C NMR (δ ppm): 14.30
CH2CH3 at C-1, 35.40 C-5, 43.95 C-6, 60.34 CH2CH3 at C-1,
59.17 C-1, 55.85 OCH3 at phenyl rings, 121.53 C-3, 159.11
Bis cyclohexenone ester 14: IR (KBr) ν (cm−1): 3052,
1
2980, 2924, 2854, 1663, 1738, 1607, 757, 694; H NMR (δ
ppm), (J Hz): 0.93 (6H, t, CH2CH3 at C-1, J=5.2), 2.99–2.95
(2H, H5a, m), 3.14–3.00 (2H, H5a, m), 3.68–3.61 (1H, H6,
m), 3.95–3.87 (4H, m, CH2CH3 at C-1), 4.11 (1H, H1, d,
J=13.6), 6.54 (1H, d, H3, J=2.0), 7.72–7.37 (14H, m, Harom.);
13C NMR (δ ppm): 13.79 CH2CH3 at C-1, 35.28 C-5, 43.46
C-6, 59.89 CH2CH3 at C-1, 58.67 C-1, 122.89 C-3, 159.29
C-4, 169.78 C=O at C-1, 194.50 C-2, 128.70-114.68 -Carom.
,
161.74, 140.88, 129.74 ipso-C’s.
Microbiology
C-4, 169.31 C=O at C-1, 194.27 C-2, 130.10-124.16 -Carom.
,
Materials
140.28, 139.86, 138.00, 137.32 ipso-Cs.
All the clinically isolated bacterial strains namely
Staphylococcus aureus, β-Haemolytic streptococcus,
Micrococcus luteus, Bacillus subtilis, Salmonella typhii,
Shigella felxneri, Vibreo cholerae, Escherichia coli,
Pseudomonas aeruginosa, Klebsiella pneumonia and
fungal strains namely Aspergillus flavus, Aspergillus niger,
Mucor indicus, Rhizopus arrhizus and Microsporum gyp-
seum are obtained from Faculty of Medicine, Annamalai
University, Annamalainagar-608 002, Tamil Nadu, India.
Bis cyclohexenone ester 15: IR (KBr) ν (cm−1): 3063,
2986, 2925, 1664, 1738, 1600, 832, 756; 1H NMR (δ ppm),
(J Hz): 0.92 (6H, t, CH2CH3 at C-1, J=7.2), 2.99–2.94 (2H,
H5a, m), 3.12–3.05 (2H, H5a, m), 3.67–3.59 (1H, H6, m),
3.95–3.85 (4H, m, CH2CH3 at C-1), 4.09 (1H, H1, d, J=14.3),
6.52 (1H, s, H3), 7.81–7.18 (12H, m, Harom.); 13C NMR (δ
ppm): 13.79 CH2CH3 at C-1, 35.27 C-5, 43.39 C-6, 59.89
CH2CH3 at C-1, 58.59 C-1, 122.84 C-3, 158.07 C-4, 169.15
C=O at C-1, 194.19 C-2, 128.91-115.64 -Carom., 162.11,
140.25, 133.80, 129.00 ipso-C’s.
In vitro antibacterial and antifungal activity by disc
diffusion method
Bis cyclohexenone ester 16: IR (KBr) ν (cm−1): 3030,
2977, 2926, 2854, 1658, 1738, 1601, 811, 756; H NMR (δ
1
e in vitro activities of the compounds are tested in
Sabourauds dextrose broth (SDB) (Hi-media, Mumbai)
for fungi and nutrient broth (NB) (Hi-media, Mumbai)
for bacteria by the disc diffusion method following the
reported method25. e respective hydrochlorides of the
test compounds 14–19 are dissolved in water to obtain
1 mg ml−1 stock solution and the different concentrations
(100, 200, 500 ppm) were prepared from the stock solu-
tion. Seeded broth (broth containing microbial spores) is
prepared in NB from 24-h-old bacterial cultures on nutri-
ent agar (Hi-media, Mumbai) at 37 1°C while fungal
ppm), (J Hz): 0.92 (6H, m, CH2CH3 at C-1, J=7.0), 2.33
(6H, s, CH3 at phenyl rings), 2.99–2.95 (2H, H5a, m), 3.13–
3.04 (2H, H5a, m), 3.68–3.57 (1H, H6, m), 3.92–3.90 (4H,
m, CH2CH3 at C-1), 4.09 (1H, H1, d, J=14.3), 6.52 (1H, s,
H3), 7.63–7.24 (12H, m, Harom.); 13C NMR (δ ppm): 14.30
CH2CH3 at C-1, 21.32, 21.34 CH3 at phenyl rings, 35.66,
35.56 C-5, 43.96, 44.08 C-6, 60.40, 60.37 CH2CH3 at C-1,
59.17 C-1, 123.88, 122.55 C-3, 159.63, 158.93 C-4, 169.85,
169.73 C=O at C-1, 194.71 C-2, 129.93-126.78 -Carom.
143.02, 141.00, 140.83, 140.53, 135.54, 134.87 ipso-C’s.
,