(5-Bromo-2-chlorophenyl)-hydrazine synthesis

Yield:98141-96-9 83%

Reaction Conditions:

Stage #1: 5-bromo-2-chloroanilinewith hydrogenchloride;sodium nitrite in water at 0; for 0.5 h;
Stage #2: with hydrogenchloride;tin(ll) chloride in water at 5; for 2 h;

Steps:

F-6 (5-Bromo-2-chloro-phenyl)hydrazine

A suspension of 5-bromo-2-chloro-aniline (10.3 g, 50 mmol) in concentrated HCI (70 ml.) and water (40 ml.) was cooled 0 °C and a solution of NaN02 (4.2 g, 60 mmol) in water (30 ml.) was added dropwise to the reaction mixture while maintaining the temperature at 0 °C. After stirring for 30 minutes, the suspension was transferred via cannule to a solution of SnC (30 g, 158 mmol ) in concentrated HCI (80 ml.) and cooled to 5 °C. The resulting thick suspension was stirred for 2 hours. After filtering the filter cake was washed with HCI (50 ml.) and water (100 ml_). Freeze drying gave (5-bromo-2-chloro-phenyl)hydrazine (10.6 g, 83%) as a white solid.

References:

WO2014/202703,2014,A1 Location in patent:Page/Page column 104