SYNTHESIS AND IN VITRO ANTIMICROBIAL ACTIVITY OF NOVEL SERIES OF 3,5-DIACETYLPYRIDINE COMPOUNDS

Bis diacetylpyridine derivative (1) was prepared and reacted with different halo-compounds, namely: epichlorohydrine and dichloroethyl ethyl ether to give 2a,b, respectively, and reacted with morpholine and piperidine to afford Mannich products 3a,b, successively. Compound 4 was synthesized by reaction of 1 with potassium thiocyanate. Reaction of 4 with 4-chlorobenzaldehyde, glucose and phthalic or maleic anhydrides produced 5, 6 and 7a,b. Compound 1 reacted with 4-chlorobenzaldehyde to give bisanylmethylene derivative 8. Also some new compounds 9-11 were prepared from the reaction of compound 8 with nucleophiles, namely: hydrazine hydrate, thiosemicarbazide and hydroxylamine via Michael condensation reaction. On the other hand, compound 8 was reacted with cyclohexanone and cyclopentanone to give 12a,b. The structures of newly synthesized products have been deduced on the basis of elemental analysis and spectral data. Some synthesized compounds were screened for their antimicrobial evaluation. Among the assayed compounds, derivatives 3b and 12a showed the highest antimicrobial activities.