Ammonia → 2,3,4-Trichlorophenylhydrazine

Participants

Reaction Conditions

Reaction Steps

2,3,4-Trichloroaniline (100 g) was dissolved with stirring in glacial acetic acid (875 ml) at 55°-60° C. A solution of sodium nitrite (39.5 g) in concentrated sulphuric acid (300 ml) was then added over 15 minutes at 55°-60° C. to the solution thus obtained. The viscous mixture obtained was cooled to 5°-10° C. and a solution of stannous chloride dihydrate (437 g) in concentrated hydrochloric acid (375 ml) was added at 5°-10° C. over 20 minutes. A fine, off-white solid precipitated. To aid filtration, the mixture was warmed to 60° C., allowed to cool to laboratory temperature and then filtered. The precipitate was washed on the filter with saturated aqueous sodium chloride solution (100 ml). The damp powder thus obtained was added to a stirred mixture of aqueous ammonia (1.3 liters; S.G. 0.880) and ice. The fine slurry which formed was filtered and the precipitate obtained was dried at 80° C., and boiled twice with chloroform (2×1.5 liters). The chloroform extracts were combined and evaporated to dryness to give 2,3,4-trichlorophenylhydrazine (86 g), m.p. 142°-143° C., in the form of a colourless powder.

Provenance & Evidence