Synthesis and antimicrobial studies of hydrazone derivatives of 4-[3-(2,4-difluorophenyl)-4-formyl-1H-pyrazol-1-yl]benzoic acid and 4-[3-(3,4-difluorophenyl)-4-formyl-1H-pyrazol-1-yl]benzoic acid

Abstract

Microbial resistance to antibiotics is an unresolved global concern, which needs urgent and coordinated action. One of the guidelines of the Centers for Disease Control and Preventions (CDC) to combat antibiotic resistance is the development of new antibiotics to treat drug-resistant bacteria. In our effort to find new antibiotics, we report the synthesis and antimicrobial studies of 30 new pyrazole derivatives. These novel molecules have been synthesized by using readily available starting materials and benign reaction conditions. Some of these molecules have shown activity with MIC values as low as 0.78 μg/mL against four bacterial strains; Staphylococcus aureus, methicillin-resistant S. aureus, Bacillus subtilis, and Acinetobacter baumannii. Furthermore, active molecules are non-toxic to mammalian cell

Synthesis of 4,4′-(4-Formyl-1H-pyrazole-1,3-diyl)dibenzoic Acid Derivatives as Narrow Spectrum Antibiotics for the Potential Treatment of Acinetobacter Baumannii Infections

“…In our efforts to find potent antimicrobial agents [ 13 ], we have previously reported the synthesis of phenyl substituted pyrazole derivatives as potent S. aureus and A. baumannii growth inhibitors [ 14 , 15 ]. Fluoro-substitution on the phenyl ring increased the potency of molecules significantly [ 16 , 17 ]. Similarly, coumarin and naphthalene substituted compounds also showed potent activity against the tested strains, particularly S. aureus [ 18 , 19 , 20 ].…”

Synthesis and Antimicrobial Studies of Coumarin-Substituted Pyrazole Derivatives as Potent Anti-Staphylococcus aureus Agents

“…Replacing one phenyl group with a benzyl group eliminated the activity of the resultant molecule (8). Methyl (9) and ethyl (10) substitution showed partial activity against the tested strains. Fluoro-phenyl substituted compound (11) did not show any growth inhibition of the tested bacteria.…”

“…inhibitors of a wide variety of bacteria such as methicillin-resistant S. aureus (MRSA) [14], Pseudomonas aeruginosa [15], Escherichia coli [16], and several other bacterial species [17]. In our efforts to develop potent antimicrobial agents, we have reported the synthesis and antimicrobial studies of phenyl [6,10], fluorophenyl [8,9], and naphthyl-substituted pyrazole derivatives [11]. We recently reported the synthesis, antimicrobial, and toxicological studies of coumarin-substituted pyrazole-derived hydrazones.…”

“…Multi-gram scale synthesis of pure pyrazole-derived aldehydes (4a-b) has helped to synthesize a series of hydrazone derivatives (Scheme 2). In our efforts to develop potent antimicrobial agents, we have reported the synthesis and antimicrobial studies of phenyl [6,10], fluorophenyl [8,9], and naphthyl-substituted pyrazole derivatives [11]. We recently reported the synthesis, antimicrobial, and toxicological studies of coumarin-substituted pyrazole-derived hydrazones.…”

“…The pyrazole nucleus is less susceptible to oxidative metabolism than other five-membered heterocycles [ 5 ]. Derivatives of this diazole have been reported as antimicrobial agents in a number of publications by us [ 6 , 7 , 8 , 9 , 10 , 11 ] and others [ 12 , 13 ]. Similarly, natural and synthetic coumarin derivatives have attracted considerable interest because of their various pharmacological activities ( Figure 1 ) [ 4 ].…”