Production of 3-benzoyl-2,1 -benzisoxazoles, 2-phenyl-4H-3,1 -benzoxazin-4-ones, and novel quinolinone derivatives from 2-phenylquinolin-4(1H)-ones and sodium dichloroisocyanurate

A simple synthesis of certain 3-benzoyl-2,1 -benzisoxazoles 6 is accomplished via treatment of the corresponding 2-phenylquinolin-4(1H)-one 1 with sodium dichloroisocyanurate 2 in methanolic aq. alkali; the isomeric 2-phenyl-4H-3.1 -benzoxazin-4-one 7 is also a product. Under different conditions the same reactants furnish two new types of quinolinone derivative, viz. 3,3-dichloro-2- phenylquinolin-4(3H)-one 4 and 2-alkoxy-3,3-dichloro-2,3-dihydro-2-phenylquinolin-4(1H)-one 5, as chief products; the former is an intermediate in the synthesis of products 6 and 7. Some of the chemical properties of the dichloro compounds 4 and 5 are described. Mechanistic pathways and proposals to explain the results and observations are presented.