The preparation and properties of some derivatives of N-methylazepine

Abstract

The action of potassium t-butoxide on dimethyl 4-chloromethyl-1,4-dihydro-1,2,6-trimethylpyridine-3,5-dicarboxylate (I; R = Me) causes ring expansion and yields the N-methylazepine, dimethyl 1,2,7-trimethyl-1H-azepine-3,6-dicarboxylate (XII) or its valence tautomer dimethyl 1,2,3-trimethyl-2-azabicyclo[3,2,0]hepta-3,6-diene-4,7-dicarboxylate (XIII). Some of the reactions of these products are described including the hydrogenolysis of compound (XII) to a nitrogen-free benzenoid derivative and the photolysis of (XII) to methyl 1,2,5-trimethylpyrrole-3-carboxylate (XVIII; R = Me). Other reactions of compound (I; R = Me) which involve rearrangements are detailed, including the formation of methyl 1,2-dimethylpyrrole-3-carboxylate (XVIII; R = H) by the action of methanolic potassium hydroxide. Reaction of compound (I; R = Me) with potassium cyanide yields a product which on chromatography gives a mixture of dimethyl 2-amino-3-methylterephthalate, dimethyl 2,6-dimethylfuro[2,3-b]pyridine-3,5-dicarboxylate, dimethyl 1,2,6-trimethyl-1H-pyrrolo[2,3-b]pyridine-3,5-dicarboxylate, and dimethyl 2-cyano-2,3,4-trimethyl-3-azabicyclo[4,1,0]hept-4-ene-1,5-dicarboxylate.