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-2-enoic acids with SOCl_2-Et_3N 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.
Cyclic anhydrides, maleimides, chlorosuccinimides, LFERs, substituent effect
FATURACI, YELİZ and COŞKUN, NECDET
"Substituent effects on the regioselectivity of maleamic acid formation and hydrogen chloride addition to N-aryl maleimides,"
Turkish Journal of Chemistry: Vol. 36:
5, Article 9.
Available at: https://journals.tubitak.gov.tr/chem/vol36/iss5/9