Synthetic method for 4-chlorophenylhydrazine hydrochloride

The invention discloses a synthetic method for 4-chlorophenylhydrazine hydrochloride. The synthetic method comprises the following steps: 4-bromochlorobenzene and hydrazine hydrate are taken as reaction raw materials, and a phase transfer catalyst, a solvent and a catalyst are added for a reaction; after the reaction, solids are filtered and separated, and a solvent is removed from a filtrate through distillation; hydrochloric acid is added to residues obtained after distillation, and the mixture is stirred and filtered; filter residues are washed with water and dried, and 4-chlorophenylhydrazine hydrochloride is obtained. The synthetic method aims to solve the problem of generation of a large amount of wastewater due to adoption of a current commonly used method for reduction acidification after diazotization of 4-chloroaniline, 4-bromochlorobenzene and hydrazine hydrate are taken as the reaction raw materials, the phase transfer catalyst, the solvent and the catalyst are added for the reaction, the reaction steps are simple, the wastewater produced in a 4-chlorophenylhydrazine synthetic method is reduced remarkably, sulfur dioxide is prevented from being produced through reduction of sodium sulfite, excessive hydrazine hydrate and solvent can be recovered and reused after reaction, and the method is environment-friendly.