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

Participants

Reaction Conditions

Reaction Steps

To a magnetically stirred solution of 4-chloropyrrolo(2,3-d)pyrimidine (30.0 g, 195 mmol) in acetonitrile (300 mL) at 85° C. was added N-bromosuccinimide (34.8 g, 195 mmol) portion-wise during a period of 10 minutes and the reaction mixture was stirred at 40° C. for 1 hour, then at room temperature for another 30 minutes. The reaction progress was monitored by TLC using 30% ethyl acetate in petroleum ether with iodine and 254 nm UV light to visualize the spot. The reaction mixture was allowed to stand for 1 hour so that precipitation occurred completely. The resulting solid was filtered and washed with chilled water (250 mL), then dried under high vacuum to give 5-bromo-4-chloro-7H-pyrrolo[2,3-d]pyrimidine as brown solid. LRMS (ESI) calc'd for C6H4BrClN3 [M+H]+, 232; found 232. 1H NMR (400 MHz, DMSO-D6,) δ: 12.98 (s, 1 H), 8.60 (s, 1H), 7.96 (d, J=2.4 Hz, 1H).

Provenance & Evidence