Syntheses with Nitriles, LXXIX. Methyl 3-Amino-4-carbomyl-2-cyano-2-butenoate, a Dimer of Methyl Cyanoacetate and Cyanoacetamide

Article abstract of DOI:10.1007/BF00809686

Synthesis of methyl 3-amino-4-carbomyl-2-cyano-2-butenoate is described and 2a classified as a dimer of methyl cyanoacetate and cyanoacetamide.By ammonolysis of the dimer of methyl cyanoacetate with dimethylamine and anilines, resp. the dimethylamide and anilides, resp. (2b and 3a-j) are obtained.Condensation with salicylaldehyde to the pyrone derivative 4 proves the structure of 2a, ring closure reactions in basic or acidic medium yield the pyridones 6a and 7a,b, coupling with diazonium salts the pyridazines 8a-d.The amides 2 and the anilides 3 show hindered rotation of the enamino- and the amide-group by hydrogen bonds between the nitrogen functions and the ester carbonyl (Z-form).The ΔG(excit.) values are reported. - Keywords: Cyanoacetate; Cyanoacetamide; Dimer