Nguyen LA, Nguyen TTT, Ngo QA, Nguyen TB. Fe/S-Catalyzed synthesis of 2-benzoylbenzoxazoles and 2-quinolylbenzoxazoles via redox condensation of o-nitrophenols with acetophenones and methylquinolines.
Org Biomol Chem 2021;
19:6015-6020. [PMID:
34156054 DOI:
10.1039/d1ob00976a]
[Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
An Fe/S catalyst generated in situ from FeCl2·4H2O and elemental sulfur S8 in the presence of a tertiary amine as a base was found to catalyze efficiently a 6e- redox condensation of o-nitrophenols with acetophenones and methylquinolines. The condensed products 2-benzoylbenzoxazoles and 2-quinolylbenzoxazoles were obtained in reasonable yields with water as the only byproduct at a temperature as low as 80 °C.
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