N-bromobutanimide → 5-Bromo-4-chloro-7H-pyrrolo[2,3-d]pyrimidine

Participants

Reaction Steps

To a suspension of 4-chloro-7H-pyrrolo[2,3-d]pyrimidine (E-1) (3.99 g, 26.0 mmol, 1.0 eq) in dry DCM (150 mL) under argon, N-bromosuccinimide (6.02 g, 33.8 mmol, 1.3 eq) is added and the resulting mixture is stirred at RT for 3 h. The reaction mixture is diluted with MeOH (30 mL) and then concentrated in vacuo to yield a slight brown solid. The residue is triturated with H2O (150 mL). The solid is collected by filtration and then re-crystallized in MeOH to afford the product, 5-bromo-4-chloro-7H-pyrrolo[2,3-d]pyrimidine (E-2).

Provenance & Evidence