4-Bromo-3-chloro-2-methylaniline → 5-bromo-4-chloro-1H-indazole
Reaction equation
[Br:1][C:2]1[CH:8]=[CH:7][C:5]([NH2:6])=[C:4]([CH3:9])[C:3]=1[Cl:10].[N:11]([O-])=O.[Na+]>C(O)(=O)C.O>[Br:1][C:2]1[C:3]([Cl:10])=[C:4]2[C:5](=[CH:7][CH:8]=1)[NH:6][N:11]=[CH:9]2Participants
5
Reactant 2
Product 1
Reagents, catalysts & solvents 2
Procedure
To a solution of 4-bromo-3-chloro-2-methylaniline (11 g, 49.9 mmol) in acetic acid (450 mL) was added NaNO2 (5.4 g, 78.3 mmol) in H2O (15 mL) at 10° C. The resulting mixture was stirred at room temperature for 30 minutes. Upon completion, the reaction mixture was diluted with H2O (500 mL) and extracted with EtOAc. The organic layer was dried over Na2SO4 and concentrated in vacuo. The residue was triturated with petroleum ether affording the title compound (4.5 g) as yellow solid. 1H NMR (400 MHz, DMSO-d6): δ 13.60 (s, 1H), 8.15 (s, 1H), 7.62 (d, 1H), 7.52 (d, 1H).