Hydrochloric Acid → 5-Chloro-2-[2-(phenylmethyl)hydrazinyl]benzoic acid

Participants

Reaction Steps

A solution of sodium cyanoborohydride (780 mg) in methanol (20 ml) was added to a stirred solution of 2-(benzylidenehydrazino)-5-chlorobenzoic acid (2.7 g) in THF (20 ml) containing a few milligrams of the indicator Congo Red. A methanolic solution of hydrogen chloride was added dropwise until the indicator in the reaction solution turned blue. Stirring was continued for 15 minutes. The reaction mixture was diluted with water and extracted with ethyl acetate. The extracts were washed with brine, dried (MgSO4) and evaporated to give 2-(2-benzylhydrazino)-5-chlorobenzoic acid as a solid (2.5 g) which was used without purification.

Provenance & Evidence