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

A mixture of methyl 2-aminonicotinate (prepared according to the method of WO 89/01488 at page 33, 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. customprepared
2. temperaturewas heated
3. temperatureunder reflux for 18 hours
4. additionadded
5. concentrationthe solution concentrated in vacuo
6. dissolutionThe residue was dissolved in methanol
7. additionthe dark solution treated with charcoal
8. filtrationthe mixture filtered
9. concentrationthe filtrate concentrated in vacuo
10. customThe residue was purified by column chromatography on silica gel
11. custommethanol:0.88 ammonia (97:2.5:0.5) as eluant, and the product triturated with ether

ORD record

ord-6690819859614821b2b477e1c7692a54

Source dataset

uspto-grants-2006_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07153870B2