In this research, new compounds were synthesized via the reaction of dichloroacetic acid with two moles of piperidine. The novel acid 1 was converted to its ester 2. Acid hydrizide 3 was prepared by the reaction of hydrazine hydrate with new ester 2, which was later used to prepare derivatives of Schiff bases 4-13. In the last step, Schiff bases and thioglycolic acid were reacted to give thiazolidine derivatives 14-23. All these compounds were diagnosed using melting points, FTIR, 1HNMR and mass spectroscopy. Scheme 1 shows all the synthesized compounds' reaction steps and structures. Keywords: Thiazolidine; Schiff bases; biological activity; piperidine; dichloroacetic acid.

A new ligand [N-(4-nitrobenzoylamino)-thioxomethyl] phenylalanine is synthesized by reaction of 4-nitrobenzoyl isothiocyanate with phenylalanine (1:1). It is characterized by micro elemental analysis (C.H.N.S.), FT-IR, (UV-Vis) and 1H and 13CNMR spectra. Some metals ions complexes of this ligand were prepared and characterized by FT-IR, UV-Visible spectra, conductivity measurements, magnetic susceptibility and atomic absorption. From results obtained, the following formula [M(NBA)2] where M2+ = Mn, Co, Ni, Cu, Zn, Pd, Cd and Hg, the proposed molecular structure for these complexes as tetrahedral geometry, except copper and palladium complexes are have square planer geometry.

A new ligand [4-Methoxy -N-(pyrimidine-2-ylcarbamothioyl) benzamide] (MPB) was synthesized by reactioniofi(4-Methoxyibenzoyliisothiocyanate)withi(2-aminopyri-midine). The Ligand was characterized by elemental micro analysis (C.H.N.S),(FT-IR) (UV- Vis) and (1Hi,13CNMR)spectra. Some transition metals complexes of this ligand were prepared and characterized by (FT-IR, UV-Vis) spectra conductivity measurements magnetic susceptibility and atomic absorption. From the obtained results the molecular formula of all complexes was suggested to be [M(MPB)2Cl2] (M+2i=Cu, Mn, Co ,Ni ,Zn ,Cd and Hg),the proposed geometrical structure for all complexes was an octahedral.

A new ligand [N-(4-nitrobenzoylamino)-thioxomethyl] phenylalanine is synthesized by reaction of 4-nitrobenzoyl isothiocyanate with phenylalanine (1:1). It is characterized by micro elemental analysis (C.H.N.S.), FT-IR, (UV-Vis) and 1H and 13CNMR spectra. Some metals ions complexes of this ligand were prepared and characterized by FT-IR, UV-Visible spectra, conductivity measurements, magnetic susceptibility and atomic absorption. From results obtained, the following formula [M(NBA)2] where M2+ = Mn, Co, Ni, Cu, Zn, Pd, Cd and Hg, the proposed molecular structure for these complexes as tetrahedral geometry, except copper and palladium complexes are have square planer geometry.

     This work includes the synthesis of new ester compounds containing two 1,3,4-oxadiazole rings, 15a-c and 16a-c. This was done over seven steps, starting with p-acetamido-phenol 1 and 2-mercaptobenzoimidazole 2. The structure of the products was determined using FT-IR, 1H NMR, and mass spectroscopy. The evaluation of the antimicrobial activities of some prepared compounds was achieved against four types of bacteria (two types of gram-positive bacteria; Staphylococcus aureus and Bacillus subtilis, and two types of gram-negative bacteria, Pseudomonas aeruginosa and E. Coli), as well as against one types of fungus (C. albino). The results show moderate activit against the study bacteria, and the theoretical analysis of the toxi

This new azo dye 3-((2-(1H-indol-3-yl) ethyl) diazenyl) quinoline-2-ol was subsequently used to prepare a series of complexes with the metal ions of Cr+3, Cu+2, VO+2, Mn+2and Mo+6. The compounds identified by 1H and 13C-NMR, FT-IR, UV-Vis, mass spectroscopy, as well as TGA, DSC, and C.H.N., conductivity, magnetic susceptibility, metal and chlorine content. The results showed that the ligand behaves in a bidantate, and that the complexes gave octahedral, excepting for VO+2 square pyramid was given, that all complexes are non-electrolytes. The effectiveness of mention the compounds in inhibiting free radicals was evaluated by the ability to act as an antioxidant was measured using DPPH as a free radical and gallic acid as a standard s

Objective:This study involved synthesis of a new series of different five-membered heterocyclic derivatives, testing their antioxidant activity, and examining their potential in vitro antimicrobial agents. Methods: The synthesis of the derivatives involved a three-step process. Initially, succinyl chloride was reacted with methanol, followed by a reaction with 80% hydrazine hydrate through a nucleophilic addition-elimination mechanism, resulting in the formation of succinohydrazide (I). This compound was then employed as a precursor for the synthesis of Schiff bases (II), and (III) by reacting it with m-nitro benzaldehyde and p-nitro benzaldehyde. Following this, a ring closure reaction was applied using thioglycolic acid, glycolic acid,

2-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

Mixed ligand complexes of bivalent metal ions, viz ; M= Co(II),Ni(II),Cu(II), Zn(II), Cd (II), and Hg(II) of the composition [M(Anth)2(TMP)] in 1:2:1 molar ratio, (where . AnthrH= Anthranilic acid (C7H7NO2) and Trimethoprime (TMP) = (C14H18N4O3) have been synthesized and characterized by repeated melting point determination, Solubility, Molar conductivity (Λm ),determination the percentage of the metal (M%) in the complexes by (AAS), FT-IR, magnetic susceptibility measurements [μeff (BM)] and electronic spectral data. The two ligands and their metal complexes have been screened for their bacterial activity against selected microbial strains (Gram +ve) & (Gram -ve).

Mixed ligand complexes of bivalent metal ions, viz ; M= Co(II),Ni(II),Cu(II), Zn(II), Cd (II), and Hg(II) of the composition [M(Anth)2(TMP)] in 1:2:1 molar ratio, (where . AnthrH= Anthranilic acid (C7H7NO2) and Trimethoprime (TMP) = (C14H18N4O3) have been synthesized and characterized by repeated melting point determination, Solubility, Molar conductivity (Λm ),determination the percentage of the metal (M%) in the complexes by (AAS), FT-IR, magnetic susceptibility measurements [µeff (BM)] and electronic spectral data. The two ligands and their metal complexes have been screened for their bacterial activity against selected microbial strains (Gram +ve) & (Gram -ve).