Putrescine → 5-[N-(4-pentafluoropropionamidobutan-1-yl)aminomethyl]imidazo[1,2-a]pyridine

A suspension of 15.13 g (69.69 mmol) of 5-chloromethylimidazo[1,2-a]pyridine.hydrochloride and 12.29 g (139.38 mmol) of 1,4-diaminobutane in 150 ml of acetonitrile was heated for one hour under reflux while stirring. The reaction mixture was cooled to room temperature. The resulting precipitates of 1,4-diaminobutane.dihydrochloride were filtered off. To the filtrate were added 20.61 ml (139.38 mmol) of ethyl ester of pentafluoropropionic acid and 19.43 ml (139.38 mmol) of triethylamine. The mixture was stirred for one hour at room temperature. The solvent was then distilled off under reduced pressure, and the residue was extracted with 200 ml of dichloromethane. The organic layer was washed with 150 ml of a saturated aqueous saline solution, dried over magnesium sulfate, and distilled off the solvent. The residue was purified by silica gel column chromatography (eluent; dichloromethane:methanol=20:1) to afford 13.61 g of the desired compound (53.6%, a pale yellow liquid).

1. temperaturewas heated for one hour
2. temperatureunder reflux
3. customThe resulting precipitates of 1,4-diaminobutane.dihydrochloride
4. filtrationwere filtered off
5. stirringThe mixture was stirred for one hour at room temperature
6. distillationThe solvent was then distilled off under reduced pressure
7. extractionthe residue was extracted with 200 ml of dichloromethane
8. washThe organic layer was washed with 150 ml of a saturated aqueous saline solution
9. dry with materialdried over magnesium sulfate
10. distillationdistilled off the solvent
11. customThe residue was purified by silica gel column chromatography (eluent; dichloromethane:methanol=20:1)

ORD record

ord-1620c8d6d5c9434e88168ef4a5d86bc0

Source dataset

uspto-grants-2001_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06251905B1