Synthesis and Antimicrobial Activity of Some New Benzimidazole Derivatives

Abstract

Reaction of 3-(2-methylbenzimidazol-1-yl)propanoic acid hydrazide (1) with CS 2 /KOH gave oxadiazole 2 which underwent Mannich reaction to give 3. Compound 2 was treated with hydrazine hydrate to give triazole 4 which was treated with both aldehydes and acetic anhydride to give 5 and 6, respectively. Carbohydrazide 1 was reacted with ethyl acetoacetate, acetylacetone and aldehydes to give 7, 8 and 9, respectively. Cyclocondensation of 9 with thioglycolic and thiolactic acids gave 10 and 11, respectively. Some of these compounds showed potential antimicrobial activities.

Synthesis of Schiff bases of naphtha[1,2-d]thiazol-2-amine and metal complexes of 2-(2′-hydroxy)benzylideneaminonaphthothiazole as potential antimicrobial agents

“…Various cobalt, nickel and copper metal complexes were reported to have antimicrobial activities (El-Ayaan and Abdel-Aziz, 2005;Sonmez et al, 2006). Schiff bases are characterized by the −N=CH− (imine) group which is important for elucidating the mechanism of transamination and racemisation reactions in biological systems (Lau et al, 1999) and are also known to have biological activities such as antimicrobial (Fioravanti et al, 1995;El-Masry et al, 2000;Pandeya et al, 1999), antifungal (Singh and Dash, 1998), antitumor (Desai et al, 2001) and herbicidal (Samadhiya and Halve, 2001). Schiff bases continue to occupy an important position as ligands in metal coordination chemistry (Wu et al, 2004;Aydogan et al, 2001), even almost a century since their discovery.…”

Crystal structure of bis(1-pyridin-2-yl-ethylidene)-p-tolylamine)nickel dithiocyanat, [Ni(C14H14N2)2](NCS)2

“…Up to now it is still ah ot research field, which could be attributed to their strong coordination ability and versatile coordination modes, antiseptic and antitumor activities [1,2] together with the special catalysis behavior and magnetism properties [3]. Schiff bases of pyridone and its complexes continue to be asubject of current interest.…”

Synthesis and antimicrobial activity of new 1,2,4-triazole and 1,3,4-thiadiazole derivatives

“…In this study, we selected aromatic isothiocyanate derivatives to synthesize the acyl thiosemicarbazide derivatives, since the acyl thiosemicarbazides carrying an aromatic substituents gave good yield when cyclized to 1,2,4-triazole and 1,3,4-thiadiazole derivatives. In addition, we preferred to synthesize 1,2,4-triazole and 1,3,4-thiadiazole derivatives which were attached at position-2 of the phthalazinone ring through methylene or ethylene bridges, since many compounds that carry 1,2,4-triazole and 1,3,4-thiadiazole rings have been reported to be attached to other rings through methylene or ethylene bridges in the literature [5,16].…”