1,2-Dibromoethane → 1-(4-nitrophenyl)-2,3-dihydro-1H-imidazo[1,2-a]benzimidazole

A mixture of N-(4-nitrophenyl)-1H-benzimidazol-2-amine (1.00 g) in DMF (20 mL) at ambient temperature was treated with a 60% dispersion of sodium hydride in mineral oil (393 mg) then stirred for 5 min. The mixture was treated with a solution of 1,2-dibromoethane (738 mg) in DMF (1 mL) then stirred at ambient temperature for 1 h. After this time, the reaction mixture was quenched with saturated aqueous ammonium chloride (10 mL), diluted with water (80 mL) and extracted with ethyl acetate (2×100 mL). The combined organic layers were washed with 5% aqueous lithium chloride (2×50 mL) then brine (50 mL), dried over sodium sulfate, and filtered and the filtrate was concentrated under reduced pressure. The residue obtained was purified by chromatography (silica, heptane to 1:1 ethyl acetate/heptane) to afford 1-(4-nitrophenyl)-2,3-dihydro-1H-imidazo[1,2-a]benzimidazole (63 mg) as a yellow solid.

1. stirringthen stirred at ambient temperature for 1 h
2. customAfter this time, the reaction mixture was quenched with saturated aqueous ammonium chloride (10 mL)
3. additiondiluted with water (80 mL)
4. extractionextracted with ethyl acetate (2×100 mL)
5. washThe combined organic layers were washed with 5% aqueous lithium chloride (2×50 mL)
6. dry with materialbrine (50 mL), dried over sodium sulfate
7. filtrationfiltered
8. concentrationthe filtrate was concentrated under reduced pressure
9. customThe residue obtained
10. customwas purified by chromatography (silica, heptane to 1:1 ethyl acetate/heptane)

ORD record

ord-8421b487caca4ed48565e09023f5bb73

Source dataset

uspto-grants-2015_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08940758B2