N-bromobutanimide → 3-Bromo-1-cyclohexyl-6-tosyl-6H-imidazo[1,5-a]pyrrolo[2,3-e]pyrazine

Participants

Reaction Steps

To a solution of 1-cyclohexyl-6-tosyl-6H-imidazo[1,5-a]pyrrolo[2,3-e]pyrazine (0.27 g, 0.672 mmol) in THF (10 mL) at about 0° C. was added a solution of NBS (0.12 g, 0.672 mmol) in THF (2 mL). After about 30 min, the mixture was diluted with EtOAc (20 mL) and saturated aqueous NaHCO3 (20 mL). The organic layer was separated, concentrated in vacuo, and purified by chromatography on silica gel (40 g) eluting with EtOAc:DCM:heptane (1:1:2) to provide 3-Bromo-1-cyclohexyl-6-tosyl-6H-imidazo[1,5-a]pyrrolo[2,3-e]pyrazine (0.27 g, 83%). LC/MS (Table 2, Method a) Rt=3.12 min; MS m/z 473 (M+H)+.

Provenance & Evidence