(2-broMo-5-chlorophenyl)hydrazine synthesis

Yield:922552-53-2 96%

Reaction Conditions:

with hydrazine hydrate monohydrate in (methylsulfinyl)methane at 70; for 72 h;

Steps:

Nucleophilic aromatic substitution with hydrazine monohydrate

General procedure: (2-Bromo-5-chloro-phenyl)hydrazine (6) A 250 mLround-bottom flask was charged with 1-bromo-4-chloro-2-fluoro-benzene (8.5 mL,68.0 mmol), hydrazine monohydrate (13 mL, 270 mmol) and dimethylsulfoxide (25mL) and the solution was stirred at 70 °C for 3 days. The reaction was then cooled to room temperature and water (200 mL) was added. The precipitate was collected by filtration and dried under vacuum for 16 hours to give (2-bromo-5-chloro-phenyl)hydrazine (14.5g, 65 mmol, 96% yield) as a white solid. LCMS ES⁺ m/z = 221.0 [M+H]⁺.

References:

René, Olivier;Fauber, Benjamin P. [Tetrahedron Letters,2014,vol. 55,# 4,p. 830 - 833] Location in patent:supporting information