1,3-Dibromo-5,5-dimethylhydantoin → 5-(2-benzyl-2H-indazol-6-yl)-7-bromopyrrolo[2,1-f][1,2,4]triazin-4-amine

Participants

Reaction Conditions

Reaction Steps

To a cooled (−20° C.) solution 5-(2-benzyl-2H-indazol-6-yl)pyrrolo[2,1-f][1,2,4]triazin-4-amine (600 mg, 1.76 mmol) in THF (18 mL) was added 1,3-dibromo-5,5-dimethylhydantoin (252 mg, 0.88 mmol) in 3 portions over 10 min. The mixture was stirred at −20° C. for 2 h. Saturated, aqueous Na2SO3 (20 mL) was added and the mixture warmed to rt. The mixture was extracted with ethyl acetate (2×20 mL). The combined organics were washed with 5% aqueous K2CO3 (2×20 mL), brine, dried (Na2SO4) and evaporated to provide 660 mg (89%) of the desired product, which contained trace impurities. ES-MS m/z 419.12 [M+H]+, HPLC RT (min) 3.00.

Provenance & Evidence