The thermal rearrangement of 1-substituted 1 H -azepines to derivatives of 6-aminofulvene

Rearrangement with the formation of dimethyl 3,α-dimethyl-6-methylminofulvene-2,4-dicarboxylate occurs readily when dimethyl 1,2,7-trimethyl-1H-azepine-3,6-dicarboxylate is heated under reflux in benzene, or when dimethyl 4-chloromethyl-1,4-dihydro-1,2,6-trimethylpyridine-3,5-dicarboxylate is heated in mesitylene in the presence of barium carbonate. Other examples of this rearrangement are described and the structures of the fulvenes are …