PROCESS FOR PRODUCING ACID-ADDITION SALT OF Z-ISOMER OF TRIPHENYLETHYLENE COMPOUND

摘要

A process for producing an acid-addition salt of a Z-isomer of a compound represented by general formula (I) (wherein R<1> and R<2> represent each lower alkyl, or are combined together with the nitrogen atom to which they are bonded to thereby form a nitrogenous heterocyclic group which may bear other heteroatom(s); R<3> and R<4> represent each hydrogen, lower alkyl, hydroxy, lower alkoxy, lower alkylcarbonyloxy, arylcarbonyloxy wherein the benzene ring may be substituted by one or two groups selected from among lower alkyl, lower alkoxy, halogen and cyano, benzylcarbonyloxy, mono- or di(lower alkyl)aminocarbonyloxy, or mono- or di(aryl)aminocarbonyloxy; R<5> represents lower alkyl or halogen; and n represents 1 to 6), which process comprises heating an E-isomer of a compound represented by general formula (I) or an acid-addition salt thereof, either alone or as a mixture thereof with a Z-isomer of a comound represented by general formula (I) or an acid-addition salt thereof, in an organic solvent containing hydrobromic acid.