o-Chloro-, 2-chloro-4-methoxy-, and 5-chloro-3,4-methylenedioxy-benzonitrile oxides react with phenanthrenequinone, chrysenequinone, phenanthrenequinonimine, chrysenequinonimine, and phenanthrenequinone monoxime to give a 1:1 adduct. Tetrabromo-o-quinone gives an adduct with benzonitrile N-oxide in ratio of 1:2.When benzoyl chloride or benzyl chloride was allowed to react with benzonitrile oxide, dibenzohydroxamic acid, o-benzohydroxamic benzyl ether were obtained respectively.The constitution of the products is discussed.