Acetic Acid → 3-(4-Amino-6-methyl-1H-indazol-1-yl)benzoic acid

Participants

Reaction Conditions

Reaction Steps

A suspension of 3-(4-bromo-6-methyl-1H-indazol-1-yl)benzoic acid (1450.5 g, 4.38 mol) and copper (I) iodide (42.47 g, 0.22 mol, 5 mol %) in aqueous ammonia (0.88 sg, 13.5 L) was heated in a sealed pressure vessel until a pressure of 7 Bar±0.3 Bar was generated (contents temperature ˜78° C.). Stirring was continued for a period of ca. 2 days. The reaction mixture was cooled to 20° C. and then charged in to a Controlled Lab Reactor fitted with a 5M HCl scrubber. The solution was heated at reflux to remove excess ammonia by gradually raising the contents temperature to >90° C.—end point pH 7.87. The reaction mixture was then cooled to 60±3° C. and acetic acid (725 mL, 12.7 mol) was added slowly to form a precipitate−end point pH=5.68. The batch was cooled to 5±3° C. and stirred for 825 minutes. The slurry was filtered and washed with water (3×4.5 L). The solid was dried in vacuo at 50° C. to afford the title compound (1112.3 g).

Provenance & Evidence