Synthesis of 2-substituted-5-methyl-pyridines

摘要

A process for the synthesis of compounds which are known intermediates for the pyridyloxyphenoxy herbicides as well as intermediates used in the process. Propionaldehyde and an acrylic compound, two readily available starting materials, are reacted to form a 2-formylpentanoic compound which is cyclized to a dihydro pyridone which is then oxidized to the 2-hydroxy pyridine. The hydroxypyridine may be halogenated to a 2-halopyridine.