Synthesis and Evaluation of Antimicrobial Activity of New Imides and Schiff Bases Derived from Ethyl -4-Amino Benzoate

Abstract

A series of disubstituted 1,3,4-oxadiazole derivatives, including imides and Schiff bases, was achieved from the starting material, ethyl-4-aminobenzoate, which was converted to the corresponding 4-aminobenzohydrazide (1), by its reaction with hydrazine hydrate in absolute ethanol. Two oxadiazole parent nuclei had been synthesized from (1), the first nucleus 5-(4-aminophenyl)-1,3,4-oxadiazol-2-amine(2), and the second is 5-(4-aminophenyl)-1,3,4-oxadiazole-2-thione (3). Compound (2) Obtained from stirring methanolic solution of (1) with cyanogen bromide (CNBr) and sodium bicarbonate (NaHCO3) at RT. While compound (3) was synthesized by refluxing of (1) with CS2 in the presence of (KOH), the produced potassium salt of hydrazide underwent cyclization by acidification with 10% HCl. Meanwhile, the cyclic imides derivatives (4-6) and (10-12) were synthesized by thermal fusion of (2) or (3) with acid anhydrides, While Schiffʼs bases derivatives (7-9) and (13-15) were synthesized by a conventional method involved refluxing of (2) or (3) with different aromatic aldehydes, in acidic medium (using glacial acetic acid). The new derivatives had been tested against three Gram-positive bacteria (Staphylococcus aureus, Micrococcus luteus, and Bacillus pumilus), and two Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli),and two fungal species: (Saccharomyces cerevisiae and Candida albicans). Among the synthesized derivatives, compound (15) displayed a moderate to potent antibacterial activity, against different (Gram- positive and Gram- negative) bacteria, and also showed a slight to moderate antifungal activity.

Synthesis, characterization and in vitro antimicrobial activity of cyclic imide: Isoindoline-1, 3-dione derivatives

“…Due to hydrophobicity and neutral structures, these compounds can easily cross biological membranes in vivo [3][4][5]. In view of the favourable pharmacokinetic properties, derivatives of cyclic imides have been found to exhibit wide range of biological activities such as antibacterial [6][7][8], antifungal [9,10], antiviral [11,12], analgesic [13,14], antiangiogenic [15,16], anti-HIV [17][18][19], antimalarial [20], anticancer [21,22], androgen receptor antagonistic [23], anti-inflammatory [24][25][26], anxiolytic [27,28], anti-depressive [29], anticonvulsant [30,31], hypolipidemic [32] and muscle-relaxant activities [33] etc.…”

Utilisation of bis-chloroacetamide derivative in the synthesis of new biologically active sulfide compounds

“…The starting compound 4-aminobenzohydrazide (1) has been obtained by the reported experimental conditions through refluxing ethyl 4-aminobenzoate in hydrazine hydrate. 45 The reactivity of 4-aminobenzohydrazide (1) towards chloroacetylation was tested by treatment with chloroacetyl chloride in DMF containing anhydrous potassium carbonate (Scheme 1). It was expected that a monosubstituted chloroacetamide product 2 would be obtained through chloroacetylation at the hydrazide function (-NH 2 ).…”

Molecular Docking, Synthesis and Evaluation for Antioxidant and Antibacterial Activity of New Oxazepane and Benzoxazepine Derivatives

“…Oxazepine and oxazepane are hetero seven-membered rings consisting of oxygen and nitrogen atoms 1,2 . In 1864, Hago Schiff was the first to report Schiff bases (SBs), which are commonly synthesized by the condensation of a primary amine with a carbonyl compound 3,4 . The SBs are also wellknown as imines and azomethine compounds.…”