Acridone studies. X. Reactions of the isomeric Bromo-10-methylacridones with sodium methoxide in methanol and in dimethyl sulphoxide

The isomeric 1-, 2-, 3-, and 4-bromo-10-methylacridones undergo a radical chain reduction to 10-methylacridone in the presence of sodium methoxide in methanol. Evidence for the mechanism is presented. In the presence of methanol-free dimethyl sulphoxide, the 1- and 3-bromo-10-methylacridones are cleanly converted by sodium methoxide into the respective methoxy compounds, and the rates have been measured at 40º. In the same solvent, the 2- and 4-bromo isomers are again reduced by sodium methoxide.