Synthesis and Structure Analysis of N-(Dehydroabietyl)maleamic Acid

N-(Dehydroabietyl)maleamic acid was synthesized from dehydroabietylamine and maleic anhydride.Its structure was characterized by IR,1H-and 13C-NMR spectra.The stereo structure of the title compound was also unambiguously confirmed by X-ray crystal structure analysis.The white crystal crystallizes in the monoclinic system,space group P21 with α =12.075(2),b = 10.377(2),с= 17.840(4)(A°),β = 100.31(3)°,V= 2199.3(8)(A°)3,R= 0.0618 and wR=0.1437.Two crystallographically independent molecules with different conformations co-exist in the unit.In each molecule,the two cyclohexane rings form a trans ring junction with chair and half-chair conformations,respectively.The C=C double bond between two carbonyl groups is in a Z configuration.Intermolecular and intramolecular hydrogen bonds coexist to stabilize the structure.