Chemistry of heterocyclic N-oxides and related compounds. 10. Reaction of pyridine N-oxide with 4-methyl- and 4-phenyl-substituted hantzsch esters

The corresponding dehydrogenation products were obtained in the reaction of diethyl 1,4-dihydro-2,4,6-collidine-3,5-dicarboxylates and diethyl 1,4-dihydro-4-phenyl-2, 6-lutidine-3,5-dicarboxylate with pyridine N-oxide. The reaction with dihydrocollidine is accompanied by simultaneous demethylation in the 4 position and methylation of the pyridine ring.See 1] for Communication 9.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 652–654, May, 1979.