Benzophenone imine → 1-Methyl-1H-indazol-3-amine

Participants

Reaction Steps

A mixture of palladium (II) acetate (82 mg, 2% mol) and xantphos (287 mg, 3% mol) in toluene (10 mL) was stirred for 5 minutes at ambient temperature. To the solution was added a solution of Example 2C (3.68 g, 17.4 mmol) and benzophenone imine (3.0 g, 17.4 mmol) in toluene (30 mL). The mixture was evacuated and purged with nitrogen two times, then stirred at ambient temperature for 15 minutes. sodium tert-butoxide (1.9 g, 1.4 eq) was added and the mixture was evacuated and purged with nitrogen. The mixture was heated to between 80-85° C. for 2 hours, cooled to ambient temperature and diluted with water (30 mL). The aqueous layer was separated and extracted with additional toluene (20 mL). The combined organic layers were stirred with 6 N HCl (10 mL) for 1 hour and 40 mL of water added to dissolve the solids. The toluene layer was discarded and aqueous layer filtered to remove insoluble material. The aqueous layer was adjusted to the pH of 14 with 50% NaOH and filtered to provide the title compound. The solid was dissolved in acetonitrile (25 mL) followed by the slow addition of 12 M HCl to adjust the pH to 1. The precipitate was filtered off, washed with water and dried to provide the hydrochloride salt of the title compound. 1H NMR (DMSO) δ 8.03 (d, 1H), 7.02 (dd, 1H), 6.64 (dt, 1H), 6.14 (dd, 1H), 5.73 (brs, 2H), 3.90 (s, 3H).

Provenance & Evidence