Synthesis, Characterization and Antimicrobial Screening of New Schiff Bases Linked to Phthalimidyl Phenyl Sulfonate Moiety

Abstract

A series of Schiff bases linked to phthalimidyl phenyl sulfonate moiety have been synthesized via multistep synthesis. The first step involved reaction of phthalic anhydride with aniline producing N-phenyl phthalamic acid which was subsequently dehydrated to the corresponding N-phenyl phthalimide via treatment with acetic anhydride and anhydrous sodium acetate. The synthesized imide was treated with chlorosulfonic acid in the third step producing 4-(N-phthalimidyl) phenyl sulfonyl chloride which was introduced in reaction with 4-hydroxy acetophenone in the fourth step producing 4-[4-(N-phthalimidyl) phenyl sulfonate] acetophenone and this in turn was introduced successfully in condensation reaction with various aromatic primary amines affording the desired new Schiff bases. The newly synthesized compounds were characterized through spectral data including FTIR, 1HNMR and 13CNMR. Antimicrobial activity of the prepared Schiff bases was evaluated against two types of bacteria and one type of fungi and the new Schiff bases were found to exhibit good antimicrobial activity against the tested organisms.

Synthesis of New Bismaleimide Homopolymer and Copolymers Derived from 4, 4ˉ-Bis[4-(N-maleimidyl) Phenyl Schiff Base] Tolidine

“…And sym. v C=O imide and other bands at (1668-1679) cm -1 , (1569-1598) cm -1 and (1379-1388) cm -1 which are due to v C=N, v C=C aromatic and v C-N imide respectively [15].…”

“…and sym. v NH2 while absorption bands at (1625) cm -1 and (1569) cm -1 are due to v C=N imine and v C=C aromatic respectively [15]. The FT-IR spectrum for compound (2) exhibited absorption bands at (3228-3334) cm -1 due to v O-H carboxyl and v NH amide [23].…”

“…All details of FT-IR spectral data of compounds (1-3) are detailed in Table 4. The 1 HNMR spectra of compounds (1-3) exhibited signals in the range (2.1-2.44) ppm belonging to the protons of two methyl groups bonded to phenyl rings, signals at (2.38-2.61) ppm belonging to protons of two methyl groups connected to imine and signals at (6.03-8.11) ppm belong to aromatic protons [15]. The 1 HNMR spectrum of compound (1) displayed a signal at (4.75) ppm belonging to NH2 groups protons, while the 1 HNMR spectrum of compound (2) showed signals at (7.95-7.97) ppm and (9.97-10.66) ppm belonging to NH and OH carboxyl protons.…”

“…Signals that belong to aliphatic carbons and aliphatic carbons in the imide ring appeared at (30.75-34.07) ppm, and a signal at (52.01) ppm belongs to OCH3 carbons. Other signals appeared at (125.29-152.03) ppm, (162.78) ppm, and (174.77-174.83) ppm, which belong to aromatic carbons, C=N carbons, and C=O imide, C=O ester carbons, respectively [15]. So, this work provides new important polyimides with desired properties (good fusibility and solubility), and this results in easy processing and is expected to serve a broad spectrum of applications [31].…”

“…The o-Tolidine (0.01 mol, 2.1 g) was dissolved in absolute ethanol (15 mL) and added dropwise to a solution of 4-amino acetophenone (0.02 mol, 2.7 g) dissolved in (20 mL) ethanol with three drops of glacial acetic acid, then the mixture was refluxed for 6 hours [13,14]. After the completion of reflux time, it was washed with cold ethanol [15] and recrystallized from acetone [16].…”