Hydrochloric Acid → (4-Bromo-2-fluoro-3-trifluoromethyl-phenyl)-hydrazine hydrochloride

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Reaction Steps

A sample of 4-bromo-2-fluoro-3-trifluoromethyl-phenyl aniline (4 g, 15.5 mmol) is suspended in concentrated HCl (36 mL) and cooled in an ice/salt bath. The reaction is then treated dropwise with a solution of NaNO2 (1.12 g, 16.3 mmol) in water (36 mL). The reaction is allowed to stir for 30 minutes and then treated with a solution of SnCl2 dihydrate (17.5 g, 77.5 mmol) in concentrated HCl (36 mL). The reaction is then stirred for 1 hour in an ice/water bath followed by an hour at room temperature. The reaction is then filtered and the solid is treated with aqueous 50% NaOH solution (30 mL) and ether (50 mL). The aqueous phase is extracted once more with ether and the combined organics are dried over MgSO4 and filtered. The resulting solution is treated with 5 mL of 4 M HCl in dioxane while stirring and the resulting solid is collected and dried under high vacuum to afford 2.44 g of (4-Bromo-2-fluoro-3-trifluoromethyl-phenyl)-hydrazine hydrochloride; LC/MS calculated for [M+H]+ C7H5BrF4N2: 273.0, found: 272.9.

Provenance & Evidence