1-(2-amino-5-bromo-3-chlorophenyl)ethanone

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a 0° C. solution of 1-(2-amino-5-bromo-3-chlorophenyl)ethanone (206 mg, 0.83 mmol) in 50% aqueous solution of concentrated H2SO4 was slowly added NaNO2 (73 mg, 1.0 mmol). The cooling bath was removed following the addition of NaNO2, stirred at room temperature for 1 hour and then recooled to 0° C. before addition of SnCl2.2H2O (573 mg, 2.49 mmol). The mixture was stirred at 0° C. for 1 hour before dilution with water. The solids were collected by vacuum filtration to afford 5-bromo-7-chloro-3-methyl-1H-indazole (130 mg, 64%). To a 0° C. The cooling bath was removed the addition of NaNO2 The solids were collected by vacuum filtration

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 1-(2-amino-5-bromophenyl)ethanone (200 mg, 0.93 mmol) in CH2Cl2 (5 mL) was added N-chlorosuccinimide (125 mg, 0.93 mmol). The mixture was stirred at room temperature overnight. Analysis indicated that the reaction was incomplete; therefore, additional N-chlorosuccinimide (125 mg, 0.93 mmol) was added and the mixture was stirred at room temperature overnight. The solvents were removed under reduced pressure and the residue was purified by CombiFlash (40 g column, 0-10% EtOAc/heptane) to afford 1-(2-amino-5-bromo-3-chlorophenyl)ethanone (206 mg, 89%). the mixture was stirred at room temperature overnight The solvents were removed under reduced pressure the residue was purified by CombiFlash (40 g column, 0-10% EtOAc/heptane)