N-(2-(benzyloxy)-4-bromo-6-nitrophenyl)acetamide → 7-(benzyloxy)-5-bromo-2-methyl-1H-benzo[d]imidazole

A mixture of N-{4-bromo-2-nitro-6-[(phenylmethyl)oxy]phenyl}acetamide (120 g, 329 mmol, STEP 1 in Example 1) and iron powder (55.1 g, 986 mmol) in acetic acid (500 mL) was refluxed with stirring for 6 hours. After cooling to room temperature, the mixture was filtered through a pad of Celite, and the filtrate was concentrated in vacuum. The residue was diluted with ethyl acetate (1.5 L). The resulted precipitates were filtered through a pad of Celite, and washed with ethyl acetate (500 mL). The filterate was concentrated in vacuum, and the residue was diluted with ethyl acetate (200 mL). The brine (800 mL) was added to the organic mixture, the resulted white precipitates were collected by filtration, and washed with water (200 mL) and diethyl ether (200 mL). The white solid was dissolved with dichloromethane/methanol (10:1, 1.0 L), dried over magnesium sulfate, and concentrated. The solid was triturated with diethyl ether (300 mL), collected by filtration, and dried in vacuum to afford the title compound as a white solid (54.7 g, 53%).

1. temperaturewas refluxed
2. filtrationthe mixture was filtered through a pad of Celite
3. concentrationthe filtrate was concentrated in vacuum
4. additionThe residue was diluted with ethyl acetate (1.5 L)
5. customThe resulted precipitates
6. filtrationwere filtered through a pad of Celite
7. washwashed with ethyl acetate (500 mL)
8. concentrationThe filterate was concentrated in vacuum
9. additionthe residue was diluted with ethyl acetate (200 mL)
10. additionThe brine (800 mL) was added to the organic mixture
11. customthe resulted white precipitates
12. filtrationwere collected by filtration
13. washwashed with water (200 mL) and diethyl ether (200 mL)
14. dissolutionThe white solid was dissolved with dichloromethane/methanol (10:1, 1.0 L)
15. dry with materialdried over magnesium sulfate
16. concentrationconcentrated
17. customThe solid was triturated with diethyl ether (300 mL)
18. filtrationcollected by filtration
19. customdried in vacuum

ORD record

ord-9c7b60c19be64442b2b874c9e11bbdc3

Source dataset

uspto-grants-2010_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07723321B2