| 摘要 |
1. Process for the alpha-halogenation of optionally substituted methyl-aromatics, characterised in that methyl-aromatics of the general formula see diagramm : EP0045423,P15,F2 in which R**1 and R**2 independently of one another denote hydrogen, chlorine or bromine, R**3 represents hydrogen, halogen, nitro, the sulphonic acid group, sulphonyl halide, the carboxyl group, alkoxycarbonyl, aryloxycarbonyl, carbonyl halide or the CHR**1 R**2 group, wherein R**1 and R**2 have the meaning given, or R**3 represents cyano, isocyanato, cyanato, isothiocyanato, thiocyanato, aryl, aryloxy, arylthio, aryldithio, tert.-alkyl or alkoxy, R**4 represents hydrogen, halogen, nitro, the sulphonic acid group, sulphonyl halide, the carboxyl group, alkoxycarbonyl, aryloxycarbonyl, carbonyl halide or the CHR**1 R**2 group, wherein R**1 and R**2 have the meaning given, and R**5 to R**7 independently of one another denote hydrogen or halogen, and wherein two of the radicals R**4 , R**5 , R**6 and R**7 , if they are adjacent, can be members of a fused-on aromatic or cycloaliphatic ring, and, wherein, furthermore, the aryl parts of the substituents mentioned can in turn be substituted, with the exception of optionally substituted 4-tert.-butyl toluenes, are reacted with chlorobromine or halogenating agents containing chlorobromine at a temperature of 40 to 250 degrees C, the reaction being carried out, if appropriate, in the presence of agents which form free radicals and/or under irradiation with light, and, if appropriate, in the presence of solvents.
|
