PURPOSE: To produce the subject compound without the generation of poisonous substances such as hydrocyanic acid, by reacting a ketone component or enol ether compound with a specific benzoquinone dicarboximide derivative as an oxidizing agent.

CONSTITUTION: A ketone or enol ether compound is reacted with a compound of the formula (R is H, alkyl, aryl, carboxyl group-substituted alkyl or carboxylate ester group-substituted alkyl) (e.g. 5,6-dichlorobenzoquinone-2,3- dicarboximide) to prepare the compound useful as a drug, agricultural chemical, liquid crystal component or intermediate thereof. The compound of the formula has an extremely strong oxidizing power, and derivatives thereof having various strong or weak oxidizing powers can be obtained by changing the substituent of the formula to various substituents.