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

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).

1. customwas kept below −40° C
2. additionAfter the addition
3. customThe reaction mixture was quenched with saturated NH4Cl
4. customThe organic layer was separated
5. extractionthe aqueous layer was extracted with EtOAc three times
6. washThe combined organic layers were washed with H2O, brine
7. dry with materialdried over MgSO4
8. customThe solvents were removed under reduced pressure
9. washeluted with 1:4 EtOAc

ORD record

ord-c507e5b59c954edca1bab44401324944

Source dataset

uspto-grants-2008_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07456169B2