Triethylamine → 6-Bromo-1-(tetrahydro-2H-pyran-2-yl)-1H-indazole-3-carbonitrile

Participants

Reaction Conditions

Reaction Steps

To a solution of 6-bromo-1-(tetrahydro-pyran-2-yl)-1H-indazole-3-carbaldehyde (Preparation 1, 60 g, 194 mmol) in MeCN (1.5 L) was added triethylamine (68.5 mL, 485 mmol) and hydroxylamine hydrochloride (20 g, 291 mmol). The reaction was heated at 60° C. for 3 hours. The reaction was cooled to 0° C., further triethylamine (220 mL, 1.55 mol) was added and TFAA (109 mL, 776 mmol) was added dropwise. The reaction was allowed to warm to room temperature and stirred for 2 hours. Water (2 L) was added to the reaction mixture and the resulting solid was collected by filtration. The solid was dissolved in DCM (1 L) and the resulting solution was washed with water (2×500 mL). The organic layer was dried over MgSO4 and concentrated in vacuo to give the title compound as a white solid (58.59 g) in a 99% yield.

Provenance & Evidence