SYNTHESIS AND EVALUATION OF ANTIBACTERIAL AND ANTIFUNGAL ACTIVITIES OF SOME NOVEL 2,5-DISUBSTITUTED-1,3,4-OXADIAZOLES

摘要

4-Chlorophenoxy acetic acid 2 was prepared by the condensation of phenol with monochloroacetic acid. Compound 2 was refiuxed with ethanol in the presence of HCI gas yielding ethyl (4-chlorophenoxy) acetate 3. Compound 3 was refiuxed with hydrazine hydrate in ethanol which produced 2-(4-chlorophenoxy) acetohydrazide 4. Compound 5a was synthesized by refluxing 2-(4-chlorophenoxy) acetohydrazide 4 with carbon disulfide and KOH in the presence of ethanol. Compound 5a on condensation with p-benzoquinone yielded 2-({4-[(4-chlorophenoxy)methyl]-1,3-4-oxadiazole-2-yl} sulfanyl) benzene-1,4-diol 5b. Oxadiazoles 6a-d were prepared by reacting substituted phenoxy acetic acids with 2-(4-chlorophenoxy) acetohydrazide 4 in the presence of POCI3. Further Schiff bases were synthesized by the reaction of substituted aldehydes with 2-(4-chlorophenoxy) acetohydrazide 4 in presence of ethanol. These Schiff bases on reaction with acetic anhyd gave the corresponding 3-acetyl-2,3-dihydro 1,3,4-oxadiazoles 7a-d. Synthesized compounds were characterized on the basis of spectral and analytical data. All the compounds were screened for antimicrobial activity.