NMR‐Untersuchungen zur Struktur von substituierten 3‐Aminoacrylsäureestern

Abstract
NMR Investigations on the Structure of Substituted 3‐Aminoacrylic Esters3‐Amino‐2‐cyano‐3‐methoxyacrylate 1 and 3‐amino‐3‐chloro‐2‐cyanoacrylate 2 exist in the E configuration (1a, 2a), which is stabilized by intramolecular hydrogen bonds. 1J(15N, 1H)‐coupling constants give no evidence for an equilibrium between enamine‐ (1a, 2a) and imino semiacetal (1b, 2b) tautomers.