Solvent-free Etherifications and O-Sulfonylations of 8-Hydroxyquinaldine in a Planetary Mill

We introduce solvent-free mechanochemical methods for etherifications and O-sulfonylations of 8-hydroxyquinaldine in a planetary mill. Reacting the substrate with alkyl halides in the presence of potassium carbonate (K2CO3 ) at room temperature produces 8-O-alkylated quinaldine derivatives in good to excellent yields. Performing the same reaction with aryl or alkyl sulfonyl chlorides in the presence of pyridine furnishes high to excellent yields of quinaldine-8-yl sulfonate derivatives. Both transformations use inexpensive, readily available reactants, and the processes are mild, environmentally friendly. and easy to implement.