Benzenamine hydrochloride (1:1) → 3-Chloro-4-fluorophenylhydrazine

Participants

Reaction Conditions

Reaction Steps

A mixture of 144.9 g of 3-chloro-4-fluoroaniline and 705 ml of concentrated hydrochloric acid was stirred and heated to 80° C. The mixture containing the aniline hydrochloride was allowed to cool to ambient temperature. After 24 hours, the mixture was stirred and cooled to 5°-10° C. while a solution of 69.5 g of sodium nitrite in 350 ml of water was added dropwise within 1/2 hour. After an additional 1/2 hour, the solution containing the diazonium salt was gradually added with stirring to a solution of 427 g of stannous chloride (2H2O) in 700 ml of hydrochloric acid. After 45 minutes at ambient temperature, the reaction mixture was made alkaline by the addition of 3000 ml of 50% sodium hydroxide and extracted with ether. The combined ether extracts were dried (MgSO4), filtered and concentrated to give 214.1 g (67%) of 3-chloro-4-fluorophenylhydrazine as a tan solid; melting point 75°-77° C.

Provenance & Evidence