5844
B. Narasimhan et al. / Bioorg. Med. Chem. Lett. 17 (2007) 5836–5845
(0.74 mol) was heated under reflux in presence of min-
eral acid until the completion of reaction. Once the reac-
tion has been completed, the reaction mixture was added
to 200 mL ice-cold water and the ester formed was ex-
tracted with ether (50 mL). The ether layer was sepa-
rated and on evaporation yielded the crude ester which
was then recrystallized from alcohol.
6.19–6.23 (t, 1H, terminal CH of CHACH@CHAC@O,
Jtrans = 16 Hz), 5.75–5.78 (m, 1H, CH of @CHACH3,
Jtrans = 12 Hz), 4.04–4.07 (m, 1H, CH of CH(CH3)2),
1.86–1.88 (d, 3H, CH3 of CH3ACH@), 1.15–1.32 (d,
6H, CH3 of (CH3)2). IR (KBr pellets): cmꢀ1 1151.5
(CAO), 1640 (C@C), 1713.6 (C@O), 2981.2 (CAH).
1
Analytical data for compound S23. H NMR (CDCl3): d
General procedure for synthesis of amides (S2–S19 and
S33–S39). The acid chloride of 2,4-hexadienoic acid was
prepared by reaction of 2,4-hexadienoic acid with thionyl
chloride. The solution of corresponding amine (0.1 mol)/
aniline (0.1 mol) in ether (50 mL) was added dropwise to a
solution of acid chloride (0.1 mol) in ether (50 mL) main-
tained at 0–10 °C/room temperature. The solution was
stirred for 30 min and the precipitated amide was sepa-
rated by filtration. The crude amide was recrystallized
from alcohol. In case of anilides, the precipitates of crude
anilide were treated with water and ether layer was sepa-
rated, washed successively with 5% hydrochloric acid, 4%
sodium carbonate and water to remove residual aniline.
Evaporation of ether layer yielded anilides which were
recrystallized from alcohol took place.
7.51–7.54 (t, 1H, terminal CH of CH@CH AC@O),
6.15–6.20 (d, 1H, CH adjacent to C@O, Jtrans = 20 Hz),
5.75–5.78 (m, 1H, CH of @CHACH3,Jtrans = 12 Hz),
1.86–1.85 (d, 3H, CH3 of CH3ACH@CH), 1.25–1.45
(m, 2H, CH2 of CH3CH2), 0.88–0.90 (t, 3H, CH3 of
O(CH2)3CH3). IR (KBr pellets): cmꢀ1 1265.3 (CAO),
1644.4 (C@C), 1722.4 (C@O), 2934.6 (CAH).
1
Analytical data for compound S24. H NMR (CDCl3): d
7.23–7.37 (t, 1H, terminal CH of CH@CHAC@O),
6.15–6.18 (d, 1H, CH adjacent to C@O, Jtrans = 12 Hz),
5.74–5.79 (m, 1H, CH of CH3ACH@, Jtrans = 20 Hz ),
1.84–1.88 (d, 3H, CH3 of CH3ACH), 1.52–1.65 (m,
2H, CH2 of CH3ACH2), 1.22–1.24 (d, 3H, CH3 of
OCH CH3), 0.89–0.93 (t, 3H, CH3 of CH2ACH3). IR
(KBr pellets) : cmꢀ1 1263.9 (CAO), 1613.1 (C@C),
1722.1 (C@O), 2935.8 (CAH).
Structure of synthesized compounds was confirmed on
the basis of their spectroanalytical data.
1
Analytical data for compound S33. H NMR (CDCl3): d
1
Analytical data for compound S4. H NMR (CDCl3): d
7.26–7.73 (m, 5H, ArH), 7.07–7.11 (t, 1H, NH), 1.83–
1.87 (d, 3H, CH3), 5.90–5.93 (m, 1H, CH of
CH3ACH@, Jtrans = 12 Hz ), 6.03–6.20 (m, 2H, terminal
CH of @CHACH@CHA). IR (KBr pellets): cmꢀ11495.6
(C@C, aromatic), 1610 (C@C), 1657.7 (C@O), 3054.4
(CH), 3302 (NH).
7.47–7.53 (m, 4H, ArH), 7.25–7.29 (t, 1H, terminal
CH of CH@CHAC@O, Jtrans = 16 Hz), 6.82–6.85 (d,
1H, CH adjacent to C@O), 5.87–5.90 (m, 1H, CH of
@CHACH3, Jtrans = 12 Hz), 1.83–1.87 (d, 3H, CH3 of
CH3ACH@). IR (KBr pellets): cmꢀ1 1608.27 (C@C),
1660.2 (C@O), 3080.0 (CH), 3299.7 (NH).
1
Analytical data for compound S35. H NMR (CDCl3): d
1
Analytical data for compound S11. H NMR (CDCl3): d
7.25–7.33 (m, 4H, ArH), 7.00–7.03 (d, 1H, CH adjacent
to C@O, Jtrans = 12 Hz), 6.17–6.23 (t, 1H, terminal CH
of CHACH@CHAC@O), 5.92–5.96 (m, 1H, CH of
@CHACH3, Jtrans = 16 Hz), 1.86–1.93 (d, 3H, CH3 of
CH3ACHA). IR (KBr pellets): cmꢀ1 1473.1 (C@C, aro-
matic), 1617.7(C@C, aliphatic), 1659.8 (C@O), 3025.7
(CAH, aromatic), 3265.6 (NH).
7.31–7.37 (dd, 1H, central CH of @CHACHACH@),
7.27 (s, 2H, NH2), 6.22–6.26 (m, 1 H, CH of
@CHAC@O, Jtrans = 16 Hz), 5.75–5.79 (d, 1H, CH of
CH3ACH@, Jtrans = 16 Hz), 1.83 (d, 3H, CH3). IR
(KBr pellets): cmꢀ1 1611.4 (C@C), 1637.9 (C@O),
2969.5 (CH), 3100 (NH).
1
Analytical data for compound S12. H NMR (CDCl3): d
Antibacterial assay. A 24-h fresh culture was obtained
by inoculation of respective bacteria in double strength
nutrient broth-IP followed by incubation at 37 1 °C.
The stock solution of synthesized 2,4-hexadienoic acid
derivatives was serially diluted in tube containing 1 mL
of sterile double strength nutrient broth—IP to get a
concentration of 50 to 3.125 lg/mL and then inoculated
with 100 lL of suspension of respective organisms in
sterile saline (S. aureus, B. subtilis and E. coli). The inoc-
ulated tubes were incubated at 37 1 °C for 24 h and
minimum inhibitory concentrations (MIC) were deter-
mined. From the observed MIC values, the exact MIC
values were determined by making suitable dilution of
stock solution.
6.14–6.26 (d, 1H, CH of @CHAC@O), 5.75–5.79 (d, 1H,
CH of CH3ACH@, Jtrans = 16 Hz), 6.19–6.22 (d, 1H,
CH of RACHAC@O, Jtrans = 12 Hz), 2.75 (s, 6H, CH3
of N(CH3)2), 1.83–1.91 (d, 3H, CH3 of CH3ACH@).
IR (KBr pellets): cmꢀ1 1637.5 (C@O), 3026.2 (NH),
2925.7 (CAH).
1
Analytical data for compound S20. H NMR (CDCl3): d
7.22–7.28
(dd,
1H,
central
CH
of
R@CHACH@CHAC@O), 6.09–6.22 (d, 1H, CH of
R@CHAC@O, Jtrans = 12 Hz), 5.75–5.79 (m, 1H, CH
of CH3ACH@, Jtrans = 16 Hz), 4.17–4.22 (m, 2H, CH2
of OACH2ACH3), 1.84–1.87 (d, 3H, CH3 of
CH3ACH@), 1.29 (t, 3H, CH3 of OACH2ACH3). IR
(KBr pellets): cmꢀ1 1140.6 (CAO), 1619.6 (C@C ),
1713.4 (C@O), 2937.8 (CAH ).
Antifungal assay. The antifungal activity of synthesized
2,4-hexadienoic acid derivatives against the fungal spe-
cies C. albicans and A. niger was determined by serial
dilution method similar to Antibacterial assay using
Sabouraud dextrose broth-IP. The inoculated tubes
1
Analytical data for compound S22. H NMR (CDCl3): d
7.29–7.37 (t, 1H, terminal CH of CH@CHAC@O),