Hydrochloric Acid → 5-ethyl-4-phenyl-1H-imidazole

Temperature

70 °C

An aqueous solution (5 mL) of concentrated hydrochloric acid (0.6 mL) and sodium thiocyanate (1.62 g, 20.03 mmol) was added to a solution of 2-aminopropiophenone hydrochloride (2.00 g, 10.02 mmol) in ethanol (20 mL). The obtained mixture was stirred at 70° C. for 1 hour. The solvent was distilled away, and acetic acid (20 mL) was then added to the residue. The obtained mixture was stirred at 100° C. for 3 hours. Thereafter, water was added to the reaction solution, and the precipitated crude crystals were collected by filtration. Raney Ni was added to a solution of the obtained crude crystals in ethanol (40 mL), and the obtained mixture was then stirred at 70° C. for 2 hours. The reaction solution was filtered with celite, and the filtrate was then concentrated. The residue was washed with acetonitrile, so as to obtain the title compound (0.88 g, yield in two steps: 45%).

1. distillationThe solvent was distilled away
2. additionacetic acid (20 mL) was then added to the residue
3. stirringThe obtained mixture was stirred at 100° C. for 3 hours
4. additionThereafter, water was added to the reaction solution
5. customthe precipitated crude crystals
6. filtrationwere collected by filtration
7. additionRaney Ni was added to a solution of the
8. customobtained crude crystals in ethanol (40 mL)
9. stirringthe obtained mixture was then stirred at 70° C. for 2 hours
10. filtrationThe reaction solution was filtered with celite
11. concentrationthe filtrate was then concentrated
12. washThe residue was washed with acetonitrile

ORD record

ord-a4dcb7a32a0245b294193169c4f5a313

Source dataset

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08648103B2