Efficient and Selective Demethylation of Heteroaryl Methyl Ethers in the Presence of Aryl Methyl Ethers

Abstract

A new and efficient method for the demethylation of 6-membered aza-heterocyclic methyl ethers is described using lithium chloride and para-toluenesulfonic acid. This process is chemoselective for aza-heterocyclic methyl ethers in the presence of aryl methyl ethers.

Keywords:

• Demethylation
• lithium chloride
• 2-methoxypyrdidine
• p-toluenesulfonic acid
• pyridine-2-one

ACKNOWLEDGMENTS

We thank the Analytical Chemistry Department of New Drug Discovery Research, Ranbaxy Research Laboratories, for spectral and chromatographic data. We also thank Dr. Jitendra Sattigeri for helpful suggestions and comments.

Notes

^a The reactions were quenched after 30 min, and the extent of reaction was determined by HPLC.

^a All products were purified by column chromatography and characterized by ¹H NMR and mass spectroscopy.