CONDENSATION OF YNAMINES OR KETENE-N,N-ACETALS WITH AMINOESTERS - SYNTHESES OF 5- AND 6-MEMBERED NITROGEN-CONTAINING HETEROCYCLES

The addition of primary or secondary aminoesters to ynamines leads to N,N,N′-trisubstituted amidines or to ketene-N,N-acetals. Both these classes cyclise on heating by an intramolecular acylation. Starting from α- or β-aminoesters 5- or 6-membered nitrogen-containing heterocycles are obtained. The same heterocycles have been also prepared from ketene-N,N-acetals and aminoesters via transamination. Under these reaction conditions γ-aminoesters from γ-lactams. © 1969.