4060 Heacock and Hey: above for the isomeric benzo-p-toluidide. The action of heat on an aqueous solution of the diazonium sulphate gave 1: 10-dimethylphenanthridone (11; R= l- Me, R'= H) and 2-hydroxy-N-methylbenzo-o-toluidide (I11; R= o-Me, R'= H); the former was