Mechanochemical synthesis of α,β-dibromoketones using pyridinium tribromide
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Wei-Jin Chang
Abstract
α,β-Dibromo compounds are important intermediates in the synthesis of epoxides and 1,2-diols. They can α-functionalization ketones to form electrophilic atoms for subsequent substitution reactions. However, conventional bromination methods often involve hazardous solvents, prolonged reaction times and generate chemical waste. In this study, α,β-dibromoketones 2a and 2b were synthesized from aldol condensation products (1a and 1b) using pyridinium tribromide via a green and solvent-free mechanochemical approach at room temperature. The reactions afford excellent yields of 75 % and 95 %, demonstrating high efficiency and a reduced environmental footprint. Characterisations of these compounds were carried out using 1H and 13C Nuclear Magnetic Resonance (NMR) and high-resolution mass spectrometry (HRMS). This work establishes a green and energy-efficient mechanochemical bromination method, demonstrating the potential of mechanochemistry as an environmentally friendly alternative to traditional halogenation and as an efficient route to construct complex molecular frameworks relevant to pharmaceutical and synthetic chemistry applications.
Funding source: Tunku Abdul Rahman University of Management and Technology
Award Identifier / Grant number: TAR UMT Publication Incentive/86000-4923
Acknowledgments
Authors acknowledge the financial support by TAR UMT Publication Incentive under vote head FOAS/PS/86000-4923.
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Research ethics: Not applicable.
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Informed consent: Not applicable.
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Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.
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Use of Large Language Models, AI and Machine Learning Tools: Not applicable.
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Conflict of interest: The authors declare that they have no conflict of interest regarding the publication of this manuscript.
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Research funding: This work was financially supported by TAR UMT Publication Incentive with a vote head number 86000-4923.
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Data availability: Not applicable.
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Supplementary Material
This article contains supplementary material (https://doi.org/10.1515/pac-2025-0580).
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