Condensation of azomethines with dimethyl acetylenedicarboxylate

The condensation of dimethyl acetylenedicarboxylate with benzylidene- and cyclohexylideneaniline, as well as with cyclohexylidene-p-toluidine and cyclohexylidene-p-anisidine, under various conditions gave 1:1, 1:2, and 1:3 adducts. The structures of the isolated substances, which are formed as a result of the addition of the ester to the azomethines with subsequent 1,5-prototropic rearrangement (arylcyclohexenylvinylamines), as well as by cycloaddition (substituted dihydropyridines and spiro-cyclohexanedihydropyridines), are discussed. © 1984 Plenum Publishing Corporation.