Chloroacetaldehyde → 6-Fluoroimidazo[1,2-a]pyridine

To a solution of 2-amino-5-fluoropyridine (10 g) in ethanol (200 mL), a solution of chloroacetaldehyde 50% in water (56 mL, 4.0 equiv.) was added. The reaction mixture was heated at reflux 2 Hrs, then was concentrated under reduced pressure to 100 mL. The residue was diluted in AcOEt (100 mL) and washed with a saturated aqueous solution of NaHCO3 (2*150 mL). The combined aqueous were saturated with NaHCO3 and extracted back with AcOEt (2*100 mL). The combined organic layers were washed with brine (100 mL), dried over Na2SO4 and concentrated under reduced pressure.

1. temperatureThe reaction mixture was heated
2. temperatureat reflux 2 Hrs
3. concentrationwas concentrated under reduced pressure to 100 mL
4. additionThe residue was diluted in AcOEt (100 mL)
5. washwashed with a saturated aqueous solution of NaHCO3 (2*150 mL)
6. extractionextracted back with AcOEt (2*100 mL)
7. washThe combined organic layers were washed with brine (100 mL)
8. dry with materialdried over Na2SO4
9. concentrationconcentrated under reduced pressure

ORD record

ord-442b789da9d64303b5d42bf932a5024a

Source dataset

uspto-grants-2015_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09029393B2