الفهرس 
AbstractOnly 14 pages are availabe for public view
 |  | from | 123 |  |  |
| | | from | 123 | | |
Abstract
A new series of benzimidazole and benzotriazole derivatives has been synthesized. The reaction was achieved through N-and S-alkylation of1H-benzo[d][1,2,3]triazole,2-(4-methoxyphenyl)-1Hbenzo[d]imidazole and 1H-benzo[d]imidazole-2-thiol with ethyl-2-chloroacetate to give the corresponding ethyl esters which upon refluxing with hydrazine hydrate afforded the desired hydrazides. Condensation of these hydrazides with a variety of aromatic aldehydes yielded the corresponding substituted benzylideneacetohydrazides. Cyclization of the later hydrazides with 2-chloroacetyl chloride gave the corresponding β-lactam derivatives.
In addition, cyclization of 1H-benzo[d]imidazole-2-thiol with chloro acetic acid and carbon disulphide gave thiazolo and thiazeto thione derivatives respectively. While the cyclization of (1H-benzo[d]imidazol-2-yl)methanethiol with chloroacetic acid gave thiazino derivatives. On the other hand cyclocondensation of 1H-benzo[d]imidazole-2-thiol and(1H-benzo[d]imidazol-2-yl)methanethiol with substituted aromatic aldehyde in the presence of p-TsOH gave thiazeto and thiazolo derivatives respectively.
The reaction of benzimidazole hydrazide with carbon disulphide in alkaline medium afforded, after acidic treatment, oxadiazole -2-thiol which was subsequently reacted with 2-chloro acetyl chloride in the presence of triethyl amine to produce the corresponding S- alkyl oxadiazole which upon refluxing with urea and thiourea gave thiazolo and oxazolo compounds respectively.
The newly synthesized compounds were characterized by both analytical and spectral data(IR,1H-NMR and MS). Selected compounds were screened in vitro for their antimicrobial activities by disc diffusion method against different strains of Gram-positive bacteria staphylococcus aureus (ATCC 25923), streptococcus aglactiae (ATCC 29212) and Bacillus subttilus Gram-negative bacteria Escherichia coli (ATCC 25922) and Pseudomonas aureginosa (ATCC 9027) and strain of fungus Candida albicans (ATCC 125022) The results showed that most derivatives bearing β-lactam moiety have a powerful antibacterial activity, especially on Gram-negative bacteria rather than Gram positive bacteria. However, all the synthesized compounds have no anticandida activity.