1,4-Dihydropyridines
(1,4-DHPs) hold a top-notch position in the
pharmaceutical world due to a broader spectrum of applications, whereas
the carboxylic moiety has been an integral part of the physiological
world, effective food preservatives, and antimicrobial agents. Seeking
the enormous potential and applications of these two classes, we worked
to combine these to synthesize 2,2′-[3,5-bis(ethoxycarbonyl)-4-phenyl-1,4-dihydropyridine-2,6-diyl]diacetic
acid the novel dicarboxylic derivatives of 1,4-DHP (
9a
–
k
) achieved via the electro-carboxylation of
tetrasubstituted-1,4-dihydropyridines (
8a
–
k
) derivatives using Mg–Pt electrodes in an undivided
cell. The targeted compounds were established by
1
H,
13
C NMR, IR, and ESI-MS. Further, the synthesized compounds
show excellent resistance against various microbes and the activity
increased 2–3 folds after the introduction of acid groups.
Compound
9b
(against
E. coli
,
S. aureus
,
B. subtilis
,
A. niger
, and
P. glabrum
),
9d
(against
E. coli
,
K. pneumonia
,
S. aureus
,
A. janus
, and
F. oxysporum)
,
9f
(against
E. coli
and
P. fluorescens
), and
9k
(against
F. oxysporum
and
P. glabrum)
were found to be highly active at 4 μg/mL
with reference to standard amoxicillin and fluconazole. Further, the
present synthetic protocol would open new gates for other researchers
to develop new molecules by bioisosteres of these substrates.