Derivative of α,β-Dicyanostilbene: Convenient Precursor for the Synthesis of Diphenylmaleimide Compounds, E−Z Isomerization, Crystal Structure, and Solid-State Fluorescence

Autor: Juen-Kai Wang, Chin-Ti Chen, Hsiu-Chih Yeh, Yuh-Sheng Wen, Wei-Ching Wu, De-Chang Dai
Rok vydání: 2004
Předmět:
Zdroj: The Journal of Organic Chemistry. 69:6455-6462
ISSN: 1520-6904
0022-3263
Popis: A convenient and efficient procedure was developed for preparing 3,4-diaryl-substituted maleimides through the improved synthesized diaryl-substituted fumaronitrile. The synthesis of diphenyl-substituted fumaronitrile derivatives from phenylacetonitrile compounds was analyzed and improved. We found the stoichiometry of the sodium methoxide and the concentration of the starting material, phenylacetonitrile derivatives, were crucial for the high yield and easy purification of the products. Particularly, bis(4-bromophenyl)fumaronitrile, bis(3-trifluoromethylphenyl)fumaronitrile, and bis(4-methoxyphenyl)fumaronitrile were isolated in good yields of 70-90% by simple suction filtration. In addition, (1)H NMR provided compelling evidence that the E-Z isomerization was involved in the formation reaction of the maleimide compounds from either fumaronitrile or maleonitrile derivatives. Single-crystal X-ray structures of these three fumaronitrile derivatives, the first three of the kind, were obtained, revealing the nonplanar molecular structure. We ascribe the strong solid-state fluorescence of these diphenylfumaronitrile derivatives to the nonplanar structure that inhibits the close packing of the molecule aggregation and thus the fluorescence quenching.
Databáze: OpenAIRE