Substituent effects on the regioselectivity of maleamic acid formation and hydrogen chloride addition to N-aryl maleimides


Faturaci Y. , Coskun N.

TURKISH JOURNAL OF CHEMISTRY, vol.36, no.5, pp.749-758, 2012 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 36 Issue: 5
  • Publication Date: 2012
  • Doi Number: 10.3906/kim-1203-34
  • Title of Journal : TURKISH JOURNAL OF CHEMISTRY
  • Page Numbers: pp.749-758
  • Keywords: Cyclic anhydrides, maleimides, chlorosuccinimides, LFERs, substituent effect, ALPHA-CHLOROSUCCINIMIDES, EFFICIENT SYNTHESIS, MALEANILIC ACIDS

Abstract

Itaconic anhydride reacts with aryl amines to give a substituent controlled equilibrium mixture of regioisomeric (Z)-2-methyl-and (Z)-3-methyl-4-oxo-4-(arylamino) but-2-enoic acids. Electron-donating groups favor nucleophilic attack on C-5 carbonyl, while the presence of electron-withdrawing groups enhances the bias for attack on C-2 carbonyl. The treatment of (Z)-2-methyl-and (Z)-3-methyl-4-oxo-4-(arylamino) but-2enoic acids with SOCl2-Et3N in THF provided the corresponding maleimides in high yields while under the same conditions the maleic anhydride aryl amine addition products gave predominately the corresponding 3-chloro-1-arylpyrrolidine-2,5-diones and maleimides in substituent dependent ratio.