Chloroacetaldehyde → 7-Chloroimidazo(1,2-a)pyridine

To a solution of 4-chloro-pyridin-2-ylamine (25.0 g, 0.194 mol) in EtOH (250 ml) was added NaHCO3 (32.7 g, 0.389 mol) followed by a 50% solution of chloroacetaldehyde in water (37 mL, 0.292 mol). The mixture was refluxed for 6 h. The solvents were removed under reduced pressure and the crude mixture was diluted with water (250 ml) and extracted with EtOAc (2×125 ml). The combined organic layers were washed with brine (50 ml), dried (MgSO4), filtered and concentrated under reduced pressure to give 7-chloro-imidazo[1,2-a]pyridine (32.7 g). 1H NMR (400 MHz, CDCl3) δ 8.06 (1H, d), 7.64 (2H, d), 7.56 (1H, s), 6.79 (1H, dd).

1. temperatureThe mixture was refluxed for 6 h
2. customThe solvents were removed under reduced pressure
3. additionthe crude mixture was diluted with water (250 ml)
4. extractionextracted with EtOAc (2×125 ml)
5. washThe combined organic layers were washed with brine (50 ml)
6. dry with materialdried (MgSO4)
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure

ORD record

ord-bce8d1316ac044068e4e661e95048427

Source dataset

uspto-grants-2014_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08895745B2