2-Chloro-3-nitropyridine → 7-Chloro-1H-pyrrolo[2,3-c]pyridine

Participants

Reaction Steps

2-Chloro-3-nitropyridine (10 g, 63 mmol) in THF (200 mL) was cooled to −60° C. or lower. The solution was treated with vinyl magnesium bromide (200 mL, 1.0 M) at such a rate that the internal temperature was kept below −40° C. After the addition was complete, the solution was stirred for another 4-6 hours at −40° C. or less, and let warm up to room temperature gradually overnight. The reaction mixture was quenched with saturated NH4Cl. The organic layer was separated, and the aqueous layer was extracted with EtOAc three times. The combined organic layers were washed with H2O, brine, and dried over MgSO4. The solvents were removed under reduced pressure. The residue was suspended in CH2Cl2, loaded onto a silica gel column, and eluted with 1:4 EtOAc:hexanes to give 3.6 g (37%) of the desired product. MS (DCI) m/e 153 & 155 (M+H)+, 1H NMR (300 MHz, DMSO-d6): □ 12.0 (br s, 1H), 7.89 (d, J=5.4 Hz, 1H), 7.67 (m, 1H), 7.57 (d, J=5.4 Hz, 1H), 6.64 (m, 1H).

Provenance & Evidence