Adarsh Krishna TP, Pandaram S, Chinnasamy S, Ilangovan A. Oxidative radical coupling of hydroquinones and thiols using chromic acid: one-pot synthesis of quinonyl alkyl/aryl thioethers.
RSC Adv 2020;
10:19454-19462. [PMID:
35515459 PMCID:
PMC9054077 DOI:
10.1039/d0ra01519a]
[Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 05/11/2020] [Indexed: 12/21/2022] Open
Abstract
An efficient, simple and practical protocol for one-pot sequential oxidative radical C–H/S–H cross-coupling of thiols with hydroquinones (HQs) and oxidation leading to the formation of quinonyl alkyl/aryl thioethers using H2CrO4 was developed. This cross-coupling of thiyl and aryl radicals offers mono thioethers in good to moderate yield and works well with a wide variety of thiols. Similarly, this method works well for coupling of 2-amino thiophenol and HQs to form phenothiazine-3-ones 5a–c. C–S bond formation via thioether synthesis was observed using a chromium reagent for the first time. Theoretical studies on the pharmacokinetic properties of compounds 5a–c revealed that due to drug-like properties, compound 5b strongly binds with Alzheimer's disease (AD) associated AChE target sites.
Oxidative radical C–H/S–H cross coupling of hydroquinones and thiols and oxidation to quinone using a H2CrO4 system was developed.![]()
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