تحضير بعض المشتقات الحلقية غير المتجانسة الجديدة وتقييم اولي لفعاليتها ضد البكتريا

Synthesis of Some New Heterocyclic Derivatives and Preliminary Evaluation of Their Antibacterial Activity

Abstract

A coupling reaction of aryl diazonium salt for 2-aminobenzothiazole (1) with phenoxide salt for 2-hydroxybenzaldehyde afforded azoaldehyde derivative arometic (2) which was undergone in condensation reactions with some primary amines (4-nitroaniline, 3-nitroaniline, 2-nitroaniline, 4-chloroaniline, 2-chloroaniline, 2,4-dichloroaniline, 4-bromoaniline, 3-bromoaniline, 4-aminoophenol, 3-aminophenol, 2-aminophenol, 2-methoxyaniline, 2,4-dimethylaniline and 4-acetamidoaniline), respectively by microwave irradiation technique to give Schiff bases derivatives (3a-n). The resulting imines were introduced in cyclization reaction with α-chloroacetyl chloride in N,N-dimethylformamide as solvent using microwave method to yield the target azetidin-2-one derivatives (4a-n), respectively, Scheme (I).
The chemical structures of the target compounds synthesized were deduced from (CHNS) elemental analysis and FT-IR, 1H NMR spectral measurements. Evaluation of activities of final β-lactam compounds (4a n) was taken place using two kinds of bacteria. Inhibition zones measurements pointed that azetidinone compounds (4b, 4c, 4i, 4j, 4k, 4m and 4n) have best impacts to reference antibiotic (amoxicillin-clavulanate) against E. coli germs. On the other hand, the β-lactam compounds (4i, 4j, 4k, 4m and 4n) indicated better activity athwart Staphylococcus aurous germs when compared with that of the standard antibiotic (amoxicillin-clavulanate) Figures (3-45), (3-46).
(I): Synthesis of azetidin-2-ones, Reagents and conditions (i) Conc. H2SO4, NaNO2, 0 oC; (ii) 2-hydroxybenzaldehyde, NaOH 10% , 5oC; (iii) Ar-NH2, EtOH, MW (300W), (40 min); (iv) α-chloroacetyl chloride, DMF, MW (300W), (150 min).