Lithium Hexamethyldisilazide → 3-(4-Bromo-6-methyl-1H-indazol-1-yl)benzoic acid

Participants

Reaction Conditions

Reaction Steps

A solution of 3-{2-[(2,6-dibromo-4-methylphenyl)methylidene]hydrazino}benzoic acid (1050 g) in DMF (3.46 L) was cooled to 10° C. under nitrogen. Lithium bis(trimethylsilyl)amide solution (1M in THF, 6.34 L) was then added while maintaining the temperature below 15° C. The stirred solution was heated at 70±3° C. for 64 hrs and then the reaction mixture was cooled to 5° C. and quenched sequentially with the slow addition of water (4.2 L), 5M hydrochloric acid (2.62 L) and water (3.68 L). The resulting slurry was stirred at 5° C. for 1 hr 34 min, filtered and washed successively with purified water (1 L and then 2.1 L at 5±5° C.) and methanol (2×1 L at 5±5° C.). The solid was dried in vacuo at 50° C. to afford the title compound (742.9 g).

Provenance & Evidence