Demethylation of 6-(2,4-dimethoxybenzoyl)chromen-2-one and some other aryl methyl ethers was achieved with pyridinium bromide as demethylating agent and sulfolane as solvent. Compared with other demethylation methods, this combination offers advantages of clean conversion, excellent yields, easy operation and workup, and manageable reaction temperatures. This process could be particularly useful for large-scale production because it avoids use of corrosive or moisture-sensitive reagents.

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Ethers. -The described method is easy, high-yielding and avoids the use of corrosive or moisture-sensitive reagents. -(SRIVASTAVA*, A.; YANG, J.; ZHAO, B.; JIANG, Y.; BLACKMON, W.; KRAEMER, B.; Synth.