Synthesis, Characterization and Antimicrobial Activity Study of Some New Substituted Benzoxazole Derivatives

Abstract

This research included the preparation of 2-mercaptobenzoxazole (N1) by the reaction of ortho-aminophenol with carbon disulfide in an alcoholic potassium hydroxide solution. The 2-mercapto benzoxazole (N1) was then treated with hydrazine to obtain the 2-hydrazino benzoxazole (N2). A number of hydrazones (N3-N5) were prepared through the reaction of N2 with different benzaldehydes. The compound (N6) was also prepared whereby the ring closing of hydrazone (N3) using chloroacetylchloride, while the compound (N7) was prepared by treating 2-hydrazino benzoxazole with acetylacetone. When the compound (N1) was treated with formaldehyde, it afforded the compound (N8). Also, the N9 was obtained from the reaction of N1 with chloroacetic acid in the presence of alcoholic potassium hydroxide. The prepared compounds were characterized using physico-chemical and spectroscopic methods such as melting point, infrared spectroscopy (IR) and the proton nuclear magnetic resonance (1H-NMR). Thereafter, some of the compounds were selected for in vitro antibacterial activity and one of these compounds showed an inhibition effect against gram positive only which is very important because it is considered as specific antibacterial drug.

Targeting Mycobacterium tuberculosis: Synthesis, in vitro and in silico evaluation of novel N1‐(benzo[d]oxazol‐2‐yl)‐N4‐arylidine compounds

“…[ 17 ] Benzo[ d ]oxazole‐2‐thiol ( 1 ) was treated with 80% hydrazine hydrate to afford 2‐hydrazinylbenzo[ d ]oxazole ( 2 ). [ 18 ] A cooled solution of 2‐hydrazinylbenzo[ d ]oxazole ( 2 ) in presence of trimethylamine and dichloromethane was sequentially treated with ethyl chloroformate to afford ethyl 2‐(benzo[ d ]oxazol‐2‐yl)hydrazine‐1‐carboxylate ( 3 ).…”

“…prepared as previously described. [17,18] The InChI codes of the investigated compounds, together with some biological activity data, are provided as Supporting Information.…”

Anticancer Activities of Some Heterocyclic Compounds Containing an Oxygen Atom: A Review

“…Benzoxazole (compound XXVI) is an organic heterocyclic compound that has a benzene ring fused with an oxazole ring [38,39]. Benzoxazole derivatives are found to have different anticancer activities [40].…”

Crystal structure and cytotoxic activity of Cu(ii) complexes with bis-benzoxazolylhydrazone of 2,6-diacetylpyridine

“…It is known that compounds containing a benzoxazole fragment have possessed variety types of biological activity: anticancer, 30–36 analgesic, 37,38 antimicrobial, immunomodulatory, antituberculosis, etc. 39–50 Hydrazones based on hydrazinobenzoxazole and their complexes are practically not described in the literature, but the available examples of these compounds also exhibit anticancer properties. 51,52…”

“…It is known that compounds containing a benzoxazole fragment have possessed variety types of biological activity: anticancer, [30][31][32][33][34][35][36] analgesic, 37,38 antimicrobial, immunomodulatory, antituberculosis, etc. [39][40][41][42][43][44][45][46][47][48][49][50] Hydrazones based on hydrazinobenzoxazole and their complexes are practically not described in the literature, but the available examples of these compounds also exhibit anticancer properties. 51,52 Thus, here we report the results of the synthesis, identification and study of physicochemical and cytotoxic properties of 2,6-diacetylpyridine bis-benzoxazolylhydrazone (H 2 L) (1) and its copper(II) coordination compounds [Cu(HL) NO…”