There is a continuous and massive need for newer cephalosporins that should have resistance against β-lactamases and can be used orally. An approach of using cephalexin, as a well-studied and potent antibacterial compound is considered to prepare new designed derivatives.  These derivatives include the incorporation of amino acid moiety linked through an amide bond with the α-amino group of cephalexin. Certain aliphatic amino acids were used, such as glycine, alanine, valine and proline. The chemical structures of these derivatives were confirmed by IR spectroscopy and elemental analyses. All the synthesized compounds were subjected for preliminary evaluation of antimicrobial activity using well diffusion method, against certa

A new series of ?-D-glucose as Schiff bases derivatives is synthesized and characterized with studying their bioactivity. Hydroxyl groups at C (1,2&5,6) sugar moiety are converted into acetal form through a reaction with dry acetone using phosphoric acid and anhydrous zinc chloride as catalysts producing 1,2:5,6-di-O-isopropyledine ?-D-glucofuranose(I). The five memberd ring acetal of C(5,6) is hydrolyzed with acetic acid (65%)and a reaction of the new product with sodium periodate is carried on to get an aldehyde moiety which is used to produce a new series of Schiff bases through reacting with different amino compounds such as 4-amino antipyrene . The suggested chemical structures of the prepared compounds are confirmed by using UV., FT

   The new C-5 schiff bases derived from D-erythroascorbic acid contaning pyrimidine unit were synthesized by condensation of D-erythroascorbic acid with aromatic amine (containing pyrimidine unit)in dry benzene using glacial acetic acid as a catalyst.               D-erythroascorbic acid was synthesized by four steps(Schem 1), while the aromatic amine which is containing oxopyrimidine or thiopyrimidine synthesized by the reaction of chalcone urea or thiourea in acid or basic medium, respectively  .              The structure of synthesized compounds have been characterized by their melting

     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

         In this study  new  derivatives  of  Schiff bases 5-8 , 1,3- oxazepine  9-16 and tetrazoles 17-19 have  been synthesized from the new starting  material 1 which has  synthesized  the reaction of  one mole of dichloro acetic acid and two moles of  thiophenol , the esters  2-3 were synthesized from the reaction of  compound 1 with methanol or ethanol respectively  in the presence of  H₂SO₄  as  catalyst  then 2,2-dithiophenylaceto Hydrazide  4 were synthesized from the reaction of  2 or 3 with hydrazine hydrate  80 % , Schiff bases 5-8 were  synthesized from the

 In this work, the preparation of some new oxazolidine and thiazolidine derivatives has been conducted. This was done over two steps; the first step included the synthesis of Schiff bases A1-A5 in 72-88% yields by the condensation of isonicotinic acid hydrazide and aldehydes. The second step includes the cyclization of derivatives A1-A5 with glycolic acid and thioglycolic acid to obtain the desired products, oxazolidine derivatives B1-B5 (44-60% yields) and thiazolidine derivatives C1-C5 (41-61% yields), respectively. The structure of the prepared compounds was characterized using FT-IR, 1H NMR, and 13C NMR spectroscopy. Some of the produced compounds were tested for antioxidant properties.