Till now, isatin derivatives have received a lot of interest in organic and medicinal chemistry due to their significant biological and pharmacological activities. Schiff’s and Mannich bases of isatins are an effective group of heterocyclic derivatives that play a significant role in medicinal chemistry as antimicrobial agents. In light of these facts, new Schiff bases and Mannich bases of isatin were synthesized. The monomer Mannich bases; 3(a-e) have been synthesized by reacting isatin with different secondary amines, piperidine, morpholine, and pyrrolidine, dimethylamine, diphenylamine, separately, and formaldehyde, while the dimer (5) formed by using piperazine and formaldehyde which then react separately with Phenylhydrazine to form new Schiff bases 4(a-e), and dimer Schiff base (6) as final products. The structures of the newly synthesized compounds were identified using two spectroscopic methods; (Fourier- transform infrared) FTIR and proton nuclear magnetic resonance spectroscopy (¹H-NMR) analysis. The preliminary in vitro antibacterial and antifungal screening results of new isatin derivatives [4(a-e) and 6] reported moderate to potent antimicrobial activity, the compound 4c exhibited moderate broad-spectrum antibacterial and antifungal activities compared to other derivatives. Moreover, compounds 4c and 6 have a good inhibitory effect against B. subtilis while amoxicillin (standard drug) shows no activity. For antifungal activity compounds (4a-c and 4e) have considerable activity towards C. albicans, whereas compound 4d exhibits slight activity and 6 of no activity.
Four metal complexes of Schi base ligand were prepared. To characterize both the ligand and the metal complexes, various techniques were employed, including elemental analysis, FT-IR spectroscopy, UV-Vis spectroscopy, molar conductivity measurements, magnetic moment determination, melting point, mass spectroscopy, 1H-NMR and 13C-NMR spectroscopy. The results showed that the metal complexes formed have the formula [M(L)2Cl2]Cl(n).H2O, where LD Schi base ligand and MDCr(III), Rh(III), Pt(IV) and Au(III), n D 1, 2. Based on spectroscopic analysis, coordination with metal ions involves the ’N’ donor atom of N atoms of the imine and the N-H amid group, and four complexes are suggested to have a six-coordinated octahedral structure. Molar c
... Show MoreThis work involves synthesis of some new heterocyclic compounds including 1, 3-diazetine. The new Schiff bases [VI] ad derived from 3-((5-hydrazinyl-4-phenyl-4H-1, 2, 4-triazol-3-yl) methyl)-1H-indole [V] which was synthesized by refluxing 5-((1H-indol-3-yl) methyl)-4-phenyl-4H-1, 2, 4-triazole-3-thiol [IV] with hydrazine hydrate in absolute ethanol and this amino compound [V] condensation with different aromatic aldehydes in absolute ethanol to yielded a new Schiff bases [VI] ad. N-acyl compounds [VII] ad were synthesized by addition reaction of acetyl chloride to imine group of Schiff bases in dry benzene. The new diazetine derivatives [VIII] ad synthesized by the reaction of N-acyl compounds [VII] ad with sodium azide in dimethylformamid
... Show MoreIn this study, new derivatives of Schiff bases of 2-thio-5-aryl1,3,4-oxadiazole have been synthesized. The structures of these derivatives were characterized from their melting points, infrared spectroscopy and elemental analysis. The Schiff bases derivatives were tested for inhibition of E-coli and were all found to be active.
Trimethoprim derivative Schiff bases are versatile ligands synthesized with carbonyl groups from the condensation of primary amines (amino acids). Because of their broad range of biological activity, these compounds are very important in the medical and pharmaceutical fields. Biological activities such as antibacterial, antifungal and antitumor activity are often seen. Transition metal complexes derived from biological activity Schiff base ligands have been commonly used.
Aromatic Schiff-bases are known to have antibacterial activity, but most of these compounds are sparingly soluble in water. The present work describes the synthesis of new Schiff-bases derived from branched aminosugars. Treatment of 3-Amino-3-Cyano-3-Deoxy-1,2:5,6-Di-O-Isopropylene-α-D-Allofuranose (1) with the aldehydes (2) under reflux in methanol afforded the Schiff-bases (3) in good yields. The new Schiff-bases were in accord with their NMR, IR spectral data and elemental analysis.
A Schiff base ligand (L) was synthesized via condensation of N-( 1-naphthyl) ethylenediamine dihydrochloride with phthalaldehyde. The ligand was characterized by FT-IR, UV–Vis, 1H NMR, mass spectrometry, and elemental analysis (C, H, N). Five metal complexes (Co(II), Ni(II), Cu(II), Zn(II), and Cd(II)) were prepared with the ligand in a 1:1 (M:L) ratio using an aqueous ethanol solution. The complexes were characterized by FT-IR, UV–Vis, mass spectrometry, and elemental analysis (C, H, N). Additionally, 1H NMR spectroscopy was employed for Cd(II) complex. Antimicrobial activity of the ligand and its metal complexes against pathogenic bacteria (K. pneumoniae, E. coli, S. aureus, and S. epidermidis) and fungus (C. albicans) were evaluated
... Show MoreNovel bidentate Schiff bases having nitrogen-sulphur donor sequence was synthesized from condensation of racemate camphor, (R)-camphor and (S)-camphor with Methyl hydrazinecarbodithioate (SMDTC). Its metal complexes were also prepared through the reaction of these ligands with silver and bismuth salts. All complexes were characterized by elemental analyses and various physico-chemical techniques. These Schiff bases behaved as uninegatively charged bidentate ligands and coordinated to the metal ions via ?-nitrogen and thiolate sulphur atoms. The NS Schiff bases formed complexes of general formula, [M(NS)2] or [M(NS)2.H2O] where M is BiIII or AgI, the expected geometry is octahedral for Bi(III) complexes while Ag(I) is expected to oxidized t
... Show MoreThis study has three parts, the first one is the synthesis of a novel Schiff bases by the condensation of guanine or 9-[{2-hydroxyethoxy}methyl]-9H-guanine with variety aldehydes to yield four different bases as follows: (E)-2-((4-nitrobenzylidene)amino)-1,9-dihydro-6H-purin-6-one (S1), (E)-2-((4-methoxybenzylidene)amino)-1,9-dihydro-6H-purin-6-one (S2), (E)-2-((2-hydroxybenzylidene) amino)-9-((2-hydroxy ethoxy)methyl)-1,9-dihydro-6H-purin-6-one (S3), and (E)-2-(((9-((2-hydroxy ethoxy)methyl)-6-oxo-6,9-dihydro-1H-purin-2-yl)imino)methyl)benzoic acid (S4). Then, spectroscopic analyses such as Elemental Analysis, UV/VIS, Mass spectra, FTIR, 1H,13C-NMR were made to recognize these bases. In the second part, the ability of synthesized bases to
... Show More2-amino-4-(4-chloro phenyl)-1,3-thiazole (1) was synthesized by refluxing thiourea with para-chloro phenacyl bromide in absolute methanol. The condensation of amine compound (1) with phenylisothiocyanate in the presence of pyridine will produce 1-(4-(4-chlorophenyl)thiazol-2-yl)-3-phenylthiourea(2), which is upon treatment with 2,4 dinitrophenyl hydrazine by conventional method, afforded 1- ( 4 - ( 4 – chlorophenyl ) thiazol – 2 – yl ) – 3 - phenylhydrazonamide,N' - ( 2 , 4 -dinitrophenyl) ,(3).The characterization of the titled compounds were performed utilizing FTIR spectroscopy, 1HNMR and CHNS elemental analysis, and by me
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