Facile and environmentally benign synthetic approach to the selective mono‐chlorination and mono‐bromination of benzo[d]OXAZOL‐2(3H)‐ONES. (24th July 2022)

• Record Type: Journal Article
• Authors: Kurutos, Atanas; Minkovska, Stela; Nedialkov, Paraskev T.; Fedorov, Yury V.
• Is Part Of: Journal of heterocyclic chemistry. Volume 59:Number 10(2022)
• Page Start: 1824
• Page End: 1831
• Publication Date: 2022-07-24
• Subjects: Heterocyclic compounds -- Periodicals; 547.59
• DOI: 10.1002/jhet.4522
• Languages: English
• ISSNs: 0022-152X

Abstract

Abstract: Exhibiting a wide spectrum of practical applications, benzo[ d ]oxazol‐2(3 H )‐ones (BOA) are considered as key intermediates in the synthesis of pharmaceutical products, organic dyes, and OLED materials among others. Herein, we propose an environmentally benign protocol for the selective mono‐halogenation of benzo[ d ]oxazol‐2(3 H )‐ones. Several chloro‐ and bromo‐substituted BOA derivatives were prepared within less than an hour with high to excellent yields (75%–93%) via this novel, green, and energy sufficient method. This rapid and highly reproducible synthetic approach employs inexpensive commercially available urea‐hydrogen peroxide complex and hydrochloric or hydrobromic acid. Simple operations and precise control over the oxidative halogenation, with water being the major by‐product of the reaction outcome, are among the strong point of current facile method from the perspective of green chemistry. Abstract : Facile, energy sufficient, and environmentally benign synthetic approach for the chlorination and bromination of BOA derivatives, employing UHP complex and hydrohalic acid. Herein, urea‐hydrogen peroxide was used as a safe and eco‐friendly oxidative reagent, with water being the major by‐product from the reaction outcome.