... [2] Part of this work was presented at the 187th American Chemical Society meeting, St. Louis, MO, 1984. ... Soc. Chim. France, 1543 (1976). [4] For pertinent references to dimethylaminomethylene- l,3-diones ■see P. Schenone, L. Mosti and G. Menozzi, J. Heterocyclic Chem., 19 ...