Hydrochloric Acid → HCID 67272164, compound

To a suspension of methyl 2-oxo-2,3-dihydro-1H-benzimidazole-4-carboxylate (35.9 g, 189 mmol) in tetrahydrofuran (700 mL) was added dropwise 3M solution of ethylmagnesium bromide in diethyl ether (374 mL, 1.12 mol), and the mixture was refluxed for 3 hr. After cooling, methanol (70 mL) was added dropwise at 0° C., and 1 N hydrochloric acid (1300 mL) was added at 0° C. The mixture was stirred at room temperature for 40 min, and the organic layer was separated and concentrated in vacuo. The aqueous layer was extracted with ethyl acetate (400 mL×2). The combined organic layer was concentrated in vacuo. The resulting solid was suspended in diisopropyl ether (70 mL)-water (10 mL)-ethyl acetate (40 mL), and the mixture was refluxed for 30 min. After cooling to room temperature, the resulting solid was collected by filtration and washed with diisopropyl ether to give the title compound (33.0 g, 150 mmol, 79%) cas a pale yellow solid.

1. temperaturethe mixture was refluxed for 3 hr
2. temperatureAfter cooling
3. customthe organic layer was separated
4. concentrationconcentrated in vacuo
5. extractionThe aqueous layer was extracted with ethyl acetate (400 mL×2)
6. concentrationThe combined organic layer was concentrated in vacuo
7. temperaturethe mixture was refluxed for 30 min
8. temperatureAfter cooling to room temperature
9. filtrationthe resulting solid was collected by filtration
10. washwashed with diisopropyl ether

ORD record

ord-2f74e6348634476b832cc68985830810

Source dataset

uspto-grants-2014_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08901141B2