Synthesis, Characterization, Antibacterial Evaluation, and Insecticidal Activity of Some Heterocyclic Compounds Containing Styrylpyridine Moiety
5-Acetyl-3-cyano-6-methyl-4-styryl/(4-methxphenyl)pyridine-2(1H)-thiones (IIa), (IIb) were synthesized via reacting ylidenecyanothioacetamides (Ia), (Ib) with acetylacetone. Treatment of compound (IIa) with certain N-aryl-2-chloroacetamides, under mild basic conditions (sodium acetate trihydrate), gave the expected 2-((5-acetyl-3-cyano-6-methyl-4-styrylpyridin-2-yl)thio)- N-arylacetamides (IIIa–IIIf). Conversion of (IIIa–IIIf) into the corresponding thienopyridines (IVa–IVf) was carrired out in boiling ethanol containing anhydrous sodium carbonate. Reaction of (IVb),(IVf) with 2,5-dimethoxytetrahydrofuran afforded pyrrolylthienopyridines (Vb), (Vf). Cyclocondensation of (IVb), (IVf) with triethyl orthoformate produced pyridiothienopyrimidinones (VIb), (VIf). Diazotization of compounds (IVb–IVd) afforded triazinones (VIIb–VIId). Compound (IIa) was treated with 2-chloromethyl-1H-benzimidazole to afford 2-(((1H-benz[d]imidazol-2-yl)methyl)thio)-5-acetyl-4-(4-methoxy- yphenyl)-6-methylnicotinonitrile (VIII). Cyclization of (VIII) into 1-(3-amino-2-(1H-benz[d]imidazol- 2-yl)thienopyridine (IX) was carried out. Compound (IX) underwent different reactions with some reagents to furnish condensed benzimidazoles (X–XIII). [1,2,3]Triazine (XIV) was synthesized via diazotization of (IX). Some of our target derivatives had been examined in vitro for their antibacterial activities against MRSA and E. coli, and promising results obtained. Most of new styrylpyridines were evaluated for their insecticidal activity towards A. gossypii (Glover, 1887) and considerable results recorded.
