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

Authors : Yeliz FATURACI, Necdet COŞKUN

Pages : 749-758

Doi:10.3906/sag-1209-30

View : 13 | Download : 7

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :Itaconic anhydride reacts with aryl amines to give a substituent controlled equilibrium mixture of regioisomeric insert ignore into journalissuearticles values(Z);-2-methyl- and insert ignore into journalissuearticles values(Z);-3-methyl-4-oxo-4-insert ignore into journalissuearticles values(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 insert ignore into journalissuearticles values(Z);-2-methyl- and insert ignore into journalissuearticles values(Z);-3-methyl-4-oxo-4-insert ignore into journalissuearticles values(arylamino);but-2-enoic 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.
Keywords : Cyclic anhydrides, maleimides, chlorosuccinimides, LFERs, substituent effect