Abstract:
In the present research work the following one series of 4-alkoxybenzaldehyde,
four series of 4-alkoxychalcones and six series of 1,3,5-trisubstituted-2-pyrazolines
bearing homologous alkoxy groups and some other subsituents have been synthesized.
Each series is comprised of twelve compounds due to the variation of the alkoxy group
ranging from CH 3 to C 12 H 25 . As a result a total of one hundred and thirty two (132)
compounds were prepared out of which 110 are new and are being reported here for the
first time.
4-Alkoxybenzaldehydes
A-Series
4-Alkoxybenzaldehydes
4-Alkoxychalcones
B-Series (E)-1-Phenyl-3-(4-alkoxyphenyl)prop-2-en-1-ones
C-Series (E)-1-(4-bromophenyl)-3-(4-alkoxyphenyl)prop-2-en-1-one
D-Series (E)-1-(4-chlorophenyl)-3-(4-alkoxyphenyl)prop-2-en-1-one
E-Series (E)-1-(4-fluorophenyl)-3-(4-alkoxyphenyl)prop-2-en-1-one
1,3,5-trisubstituted -2-Pyrazolines
F-Series 1-Acetyl-3-phenyl-5-(4-alkoxyphenyl)-2-pyrazolines
G-Series 1-Propionyl-3-phenyl-5-(4-alkoxyphenyl)-2-pyrazolines
H-Series 1-(3, 4-Dimethylphenyl)-3-phenyl-5-(4-alkoxyphenyl)-2-pyrazolines
I-Series 1-(3,4-Dimethylphenyl)-3-(4-bromophenyl)-5-(4-alkoxyphenyl)-2-
pyrazolines
J-Series
1-(3,4-Dimethylphenyl)-3-(4-chlorophenyl)-5-(4-alkoxyphenyl)-2-
pyrazolines
K-Series
1-(3,4-Dimethylphenyl)-3-(4-fluorophenyl)-5-(4-alkoxyphenyl)-2-
pyrazolines
All compounds were obtained in good yields and their purity was ascertained by
thin layer (TLC) and gas chromatography (GC). The synthesized compounds were
characterized by physical data, spectroscopic techniques, elemental analysis and single
crystal x-ray crystallography.
The synthesized 1,3,5-trisubstituted-2-pyrazolines
bearing homologous alkoxy
groups were found to possess fluorescence properties in the blue region of the visible
VIspectrum when irradiated with ultra violet radiation. The fluorescence behavior of these
compounds was studied by UV-Vis Spectroscopy and Emission Spectroscopy performed
at room temperature.
The synthesized compounds were also subjected to biological activity analysis
such as antifungal, anti-inflammatory and cytotoxicity. Many of the lead compounds
showed significant level of activity as compared to the standard drugs used as references.
Some of the 1,3,5-trisubstituted-2-pyrazolines showed broad spectrum antifungal behavior
against the tested fungi strains.
In case of in vitro anti-inflammatory activity of 1,3,5-trisubstituted-2-pyrazolines high
anti-inflammatory activity with IC 50 values comparable to the standard drug was
observed.
The brine shrimp lethality assay of the 4-Alkoxychalcones, especially that of some of the
E-series compounds exhibited highest degree of cytotoxicity with LD 50 values much
lower than the LD 50 values of the standard drug. All the synthesized 4-Alkoxychalcones
and 1,3,5-trisubstituted-2-pyrazolines were devoid of any antibacterial activity.