N-bromobutanimide → 4-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-1-methyl-4,5,6,7-tetrahydro-1H-indazol-4-ol

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-(8-chloroimidazo[1,5-a]pyrazin-3-yl)-1-methyl-4,5,6,7-tetrahydro-1H-indazol-4-ol (1 g, 3.3 mmol) in DMF (8 ml) was added NBS (584 mg, 3.3 mmol) portionwise at 0° C. After the addition was complete, the reaction mixture was stirred at 0° C. for 30 minutes. The mixture was diluted with water and extracted with ethyl acetate three times. The combined organic layers were washed with brine, dried over Na2SO4 and concentrated in vacuo. The residue was purified by preparative TLC to give 4-(1-bromo-8-chloroimidazo[1,5-a]pyrazin-3-yl)-1-methyl-4,5,6,7-tetrahydro-1H-indazol-4-ol (860 mg, 68%). MS-ESI (m/z): 382 (M+1)+ (Acq Method: 10-80AB_2 min; Rt: 1.01 min)

Provenance & Evidence