Iodine → 3,5-Dichloroaniline

Participants

Reaction Steps

200 parts of phenol, 5.7 parts of iodine, 197 parts of a tetrachloroaniline/pentachloroaniline mixture according to the data in Example 3, and 20 parts of ruthenium-on-charcoal catalyst (5% strength) are subjected to a hydrogenating dehalogenation in a tantalum autoclave at 175° C. with hydrogen under a maximum pressure of 50 bars. In the working up process, the hot mixture is dissolved in 450 parts by volume of water at 100° C., the catalyst is separated off through a suction filter and the filtrate is neutralised with sodium hydroxide solution. 3,5-Dichloroaniline and phenol are separated off from the water phase with the aid of toluene, and the organic solution is distilled. After distilling off toluene and water, the phenol is separated off from the 3,5-dichloroaniline by distillation and can be used again. The crude 3,5-dichloroaniline which remains is purified by distillation over a simple distillation bridge. 132 parts of 98% strength 3,5-dichloroaniline is obtained; yield 94% of theory.

Provenance & Evidence