Chlorobenzene dichloroethane drug intermediates o-chlorobromobenzene synthesis method

摘要

#$%^&*AU2016102221A420170216.pdf#####ABSTRACT Chlorobenzene dichloroethane drug intermediates o-chlorobromobenzene synthesis method, comprising the following steps: the reaction vessel was added in 0.8mol o-chloroaniline solution, 100ml aqueous solution, the stirring rate was controlled at 300-500rpm, 300ml sodium bromide solution was added, control the temperature of the solution within6--90 C, 0.8mol potassium bisulfate solution was added dropwise in 100-120ml aqueous solution, after complete addition the solution was maintained at a temperature of 35--40'C, the duration of the reaction is about 2-3h, potassium iodide test paper measuring the end of the reaction, generating diazonium salt (3); 0.12mol stannous chloride and 200-300ml sodium bromide with a mass fraction of 50-70% were mixed to the reaction container, the solution is heated to a temperature of 90--92 C , diazonium salt solution generated was added dropwise, maintaining the solution temperature at 93--95 C, steam distillation after addition completed until no oil distillates, the organic layer was separated and the aqueous layer was extracted with a solvent a certain number of times and the extract was combined with the oil layer, washed with phosphoric acid solution with a mass fraction of 30-40%, and washed with neutralization solution, salt solution, dehydrated with dehydrating agent, vacuum distillation after extract has been distilled, collectingfractions of 180--185 0C , ultimately colorless transparent o-chlorobromobenzene.