The synthesis of some substituted methyl pyridinecarboxylates. II. Methyl 4-substituted picolinates, methyl 5-substituted picolinates, and methyl 5-substituted nicotinates

Abstract

General methods are described for the synthesis of three series of substituted methyl pyridinecarboxylates from readily available starting materials. Methyl 4-X-picolinates and methyl 5-X-picolinates (X = NO₂, Br, MeO, Me₂N) are prepared from 2-picoline via 4-nitro-2-picoline N- oxide and 2-amino-5-nitropyridine respectively. Methyl 5-X-nicotinates (X = Br, MeO, Me₂N) are prepared from 5-bromonicotinic acid. Preparations of methyl 4-methylpicolinate and methyl 5-methylnicotinate from the corresponding lutidines and methyl 5-methylpicolinate from 2-amino-5-methylpyridine are described.