2,4,5-TRIHALOSTILBENES AND A PROCESS FOR THE PREPARATION THEREOF

摘要

- ? 2,4,5-Trihalostilbenes and a process for the preparation thereof Compounds of the formula I <IMG> (I) in which R1 to R5 independently of one another are hydrogen, alkyl(C1-C12), fluorine, chlorine, bromine, -OH, -CN, -CHO, -OAlkyl(C1-C8), -Ophenyl, -OCOalkyl(C1-C8), -OCO-phenyl, -NH2, -NHalkyl(C1-C8), -NHphenyl, -N(alkyl)2- (C1-C8), -Nphenylalkyl(C1-C8), -N(phenyl)2, -NHCOalkyl- (C1-C8), -NHCOphenyl, -NO2, CN, alkenyl, alkynyl and -CF3 and X, Y, and Z are halogen atoms. Furthermore, a process for the preparation of the compounds of the formNla (I) by reacting a compound of the formula (II) <IMG> (II) in which X, Y and Z are as already defined and W is an iodine, bromine or chlorine atom or a diazonium group N2A, in which A is an anion of an acid having a pKa < 7, with a compound of the formula (III) - ? <IMG> (III) in which R1 to R5 are as defined, in the presence of catalytic quantities or a palladium catalyst, if desired in a solvent, and in the presence or absence of a base and/or stabilizing ligands and/or quaternary ammonium salts or phosphonium salts.