... The Journal of Organic Chemistry. ... The IR spectrum revealed the presence of an ester carbonyl (ν 1748 cm - 1 ) and an imine double bond (1631 cm - 1 ) which were further corroborated by 13 C NMR (δ 154.5, s, C O; 152.2, d, 1 J CH 193 Hz, CH N). The exceptionally high ...