Design, Synthesis and Antimicrobial Activity of Novel 2-Substituted Benzoxazole DerivativesAuthor(s): G. Balaswamy, P. Pradeep, K. Srinivas and T. Rajakomuraiah
In the current research work, the title compounds were synthesized from methyl 2-substituted benzoxazole-5-carboxylate1 (1a-c) by refluxing with methanol and THF (1 : 1) in presence of NaBH4, which afforded (2-substituted benzoxazol-5-yl) methanol (2a-c), on partial oxidation with PCC furnished 2-substituted benzoxazole-5-carbaldehyde (3a-c), on treatment with appropriate carbonyl compounds monoethyl malanoate (4), ethyl acetoacetate (6) or malonic acid (8) yielded the corresponding α,β- unsaturated derivatives of 2-substituted benzoxazoles like, ethyl 3-(2-substituted benz-oxazol-5-yl) acrylate (5a-c), 4-(2-substituted benzoxazol-5-yl) but-3-en-2-one (7a-c) and 3-(2-substituted benzoxazol- 5-yl) acrylic acid (9a-c). The identification and characterization of all the synthesized compounds were confirmed by elemental analysis, melting point, thin layer chromatography, FT-IR, 1 H NMR and mass spectral data. All the compounds were screened for antimicrobial activity. In view of interesting biological activities and pharmacological importance associated with benzoxazole derivatives, some of the derivatives of benzoxazole containing heterocyclic ring have been prepared and their bio-potential have been evaluated.