To reveal the scope of the syntheses of 3-aryl-2-quinolinones from 2-nitro-α-phenylcinnamic acids, the isomerization of (E)-2-amino-α-phenylcinnamic acids was studied. The results showed that (E)-2-amino-α-phenylcinnamic acids were isomerized to its (Z)-forms under sunlight in organic solvents. The reaction temperature and the functional groups at both phenyl rings have no effect on the isomerization of (E)-2-amino-α-phenylcinnamic acids ...
