PURPOSE: To obtain a benzyidene derivative useful as a nonsteroidal antiinflammatory agent, etc., in a high purity and yield by condensing a specific quinonemethide derivative with a specified nitrogen-containing heterocyclic compound in the presence of a base.
CONSTITUTION: A compound expressed by formula I (R1 and R2 are each a lower alkyl, lower alkoxy, etc.; X is a lower alkoxy or halogen) is reacted with a compound expressed by formula II (Y is SO2, SO, etc.; A is a lower alkylene; B is CH2 or O; R is H, an aryl, etc.) in the presence of a base (preferably lithium diisopropylamide, etc.) to provide the objective compound expressed by formula III. Furthermore, compounds in which X is a methoxy such as 2,6-di- tert-butyl-4-methoxymethylen-2,5-cyclohexadien-1-one are preferred as the compound expressed by formula I and compounds in which Y is SO2 such as N- ethyl-1,2-isothiozolidine-1,1-dioxide are preferred as the compound expressed by formula II.
INAGAKI MASANAO
MATSUMOTO SAICHI
KAMATA SUSUMU
