In this work 5-methylene-yl - (2-methy –oxazole-4-one) (1H) imidazole (1) were synthesized from the reaction of L-Histidine with acetic anhydride and which converted to the of 5-methylene-yl-(2-methyl 3-amino imidazole-4-one)-1H-imidazole (2) by reaction with hydrazine hydrate. Schiff bases (3-6) were synthesized from the reaction of compound (2) with different aromatic aldehyde. Reaction of compounds (3-6) with chloroacetyl chloride gives azetidinone one derivatives (7-10). These compounds were characterized by FT-IR and some of them with 1H-NMR and 13C-NMR spectroscopy.

A group of derivatives for compounds 2-Amino-3-carboxy-4,5,6,7-tetra hydrobenz -othiophene bearing different heterocyclic moieties such as Schiff bases. B-Lactum, 4-thiazolidinone.1,3-oxazepan. The newly synthesized derivatives have been supported by spectral data FT-IR, H¹-NMR. All the synthesized compounds were screened for their antimicrobial activities against gram-positive and gram-negative bacteria as reference.

1,3-0xazepine-4)-diones were  prepared by c.ondensation of N­

cinnamylideneareneamines with maleic anhydride,  phthalic;; anhydride

,and  3-nitrophthalic  anhydride.  The  oxazepjne::; were  reacted  with

primary aromatic  amine  to give the corresponding  1 ,3--diazepine-4,7- diones.

The ligand Schiff base [(E)-3-(2-hydroxy-5-methylbenzylideneamino)- 1- phenyl-1H-pyrazol-5(4H) –one] with some metals ion as Mn(II); Co(II); Ni(II); Cu(II); Cd(II) and Hg(II) complexes have been preparation and characterized on the basic of mass spectrum for L, elemental analyses, FTIR, electronic spectral, magnetic susceptibility, molar conductivity measurement and functions thermodynamic data study (∆H°, ∆S° and ∆G°). Results of conductivity indicated that all complexes were non electrolytes. Spectroscopy and other analytical studies reveal distorted octahedral geometry for all complexes. The antibacterial activity of the ligand and preparers metal complexes was also studied against gram and negative bacteria.

The ligand Schiff base [(E)-3-(2-hydroxy-5-methylbenzylideneamino)- 1- phenyl-1H-pyrazol-5(4H) –one] with some metals ion as Mn(II); Co(II); Ni(II); Cu(II); Cd(II) and Hg(II) complexes have been preparation and characterized on the basic of mass spectrum for L, elemental analyses, FTIR, electronic spectral, magnetic susceptibility, molar conductivity measurement and functions thermodynamic data study (∆H°, ∆S° and ∆G°). Results of conductivity indicated that all complexes were non electrolytes. Spectroscopy and other analytical studies reveal distorted octahedral geometry for all complexes. The antibacterial activity of the ligand and preparers metal complexes was also studied against gram and negative bacteria.

Objective: Benzoxazole derivatives have antifungal, anticancer, antibacterial, and anticonvulsant function. Encouraged by this comment, we agreed to synthesize new Benzoxazole compounds connected to the bases of Schiff's. Methods: 2,4-diaminophenol (1) was prepared by the reaction of 2,4-dinitrophenol and sodium dithionate. Compound (1) reacted with either acetic acid to afford compound (2) or with formic acid to afford compound (3). The Schiff bases were preparation from the reaction condensing reaction of compound (2) or (3) and aromatic aldehydes or ketone; [p-nitrobenzaldehyde, p-hydroxybenzaldehyde, p-chlorobenzaldehyde, p-bromoacetophenone and terephthaldehyde]. Results: FTIR and 1H-NMR spectroscopy characterized all of the pr

In this study, new heterocyclic compounds were synthesized through the cyclization reactions of o-phenylenediamine (1) with various organic reagents. Benzodiazepine derivatives (2-4) were obtained by reaction of (1) with ethylacetoacetate, malonic acid and acetyl acetone.Treatment of compound (1) with chloroacetamide, chloroacetic acid, p-bromophenacyl bromide and oxalic acid dihydrate afforded quinoxaline derivatives (5-8), respectively. Reaction of compound (1) with benzoic acid, piperonal, cyclohexanone and carbon disulfide resulted in the formation of compounds (9-12), respectively. Finally, reaction of compound (12) with chloroacetic acid in the presence of potassium hydroxide produced compound (13).

A series of benzohydrazide derivatives attached to coumarin moiety at position 6 and 7 have been synthesized. The reaction of coumarin derivatives (coumarin I and II) with p-nitrophenyl hydrazine yield Schiff bases (compound1a and IIa_).These Schiff bases were refluxed with benzoyl chloride to give benzohydrazide derivatives of coumarin substituted at its 6 or 7 nucleus position (Ia₁ and IIa₁).The reaction and the purity of the products were checked by thin layer chromatography (TLC). The structures of the final compounds  and  their intermediates were confirmed by their melting points, infra red spectroscopy, and elemental microanalysis(CHN).

Compounds (Ia1 and IIa1) were evaluated for&n

Objectives: Two derivatives of cephalexin were synthesized by reaction with isatin-glycine Schiff base and bromoisatin-glycine Schiff base separately. Methods: Cephalexin was linked through the amine group to isatin glycine and bromoisatin glycine Schiff bases by amide bond formation. Results: These derivatives were characterized by FT-IR, H-NMR, elemental CHN analysis and then tested for their antimicrobial activity compared to cephalexin against gram-positive, gram-negative bacteria and Candida albicans fungi. Conclusion: The two compounds showed better activity against Staphylococcus aureus, compound 3b is more active against Escherichia coli, and compound 3a is more active against Klebsiella pneumonia.