Facile synthesis of 2-benzoxazoles via CuI/2,2'-bipyridine catalyzed intramolecular C–O coupling of 2-haloanilides |
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Authors: | Thachora Venu Saranya Pambingal Rajan Sruthi |
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Institution: | School of Chemical Sciences, Mahatma Gandhi University, Kottayam, India |
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Abstract: | Development of newer methods for the synthesis of Benzoxazoles has of greater interest due to their wide range of biological activities and pharmaceutical importance. We herein report a facile and general method for the synthesis of 2-substituted Benzoxazoles via copper catalyzed intramolecular C–O cross-coupling of 2-haloanilides. A combination of CuI (5?mol%), 2,2'-bipyridine (10?mol%), Cs2CO3 (2 equiv.) in DMF solvent with 4?Å molecular sieves at 140?°C, illustrated the scope for tuning the reactivity of 2-haloanilides toward the selective formation of a series of 2-alkyl benzoxazole derivatives in moderate to good yields. This is the first systematic study using CuI/2,2'-Bipyridine as the catalytic system for the synthesis of 2-substituted Benzoxazoles. The outcome of the reaction was found to be significantly influenced by the aromatic and amide substituents of 2-haloanilides. |
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Keywords: | Benzoxazole copper 2-haloanilides 2 2'-bipyridine C–O coupling |
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