Chloroacetaldehyde → Methyl imidazo[1,2-a]pyridine-8-carboxylate

A mixture of methyl 2-aminonicotinate (WO 89/01488 pg33, prep 17) (1 g, 6.56 mmol), and chloroacetaldehyde (1.05 mL, 6.56 mmol) in ethanol (5 mL) was heated under reflux for 18 hours. The cooled mixture was diluted with water (10 mL), 0.88 ammonia (1 mL) added and the solution concentrated in vacuo. The residue was dissolved in methanol and the dark solution treated with charcoal, the mixture filtered and the filtrate concentrated in vacuo. The residue was purified by column chromatography on silica gel using dichloromethane:methanol:0.88 ammonia (97:2.5:0.5) as eluant, and the product triturated with ether, to afford the title compound, 768 mg.

1. temperaturewas heated
2. temperatureunder reflux for 18 hours
3. additionadded
4. concentrationthe solution concentrated in vacuo
5. dissolutionThe residue was dissolved in methanol
6. additionthe dark solution treated with charcoal
7. filtrationthe mixture filtered
8. concentrationthe filtrate concentrated in vacuo
9. customThe residue was purified by column chromatography on silica gel
10. custommethanol:0.88 ammonia (97:2.5:0.5) as eluant, and the product triturated with ether

ORD record

ord-3337f86a728a4829ae44fa2f0b72f691

Source dataset

uspto-grants-2006_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07132435B2