Recently we required 3-methylpyridine-2-carboxaldehyde (lb) and 3-methylpyridine-4- carboxaldehyde (2b) in relatively large quantities, which necessitated the development of a synthetic method involving inexpensive starting materials. For this purpose, we studied the selective oxidation of both the lutidines (dimethylpyridines) la and 2a in some detail. Conversion of la to lb has been achieved by vapor-phase oxidation with a mixed MoO3-V, ...
