1,8-Diazabicyclo(5.4.0)undec-7-ene → HCID 57786049, compound

Participants

Reaction Steps

To a stirred solution of methyl 3-{2-[(2,4-dichlorophenyl)(hydroxy)methyl]-7-(diethylamino)-1H-benzimidazol-1-yl}propanoate (1.00 g, 2.15 mmol) and diphenylphosphoryl azide (1.39 mL, 6.46 mmol) in toluene (11 mL) was added 1,8-diazabicyclo[5.4.0]undec-7-ene (966 μL, 6.46 mol) at room temperature. After 12 h, the reaction mixture was diluted with ethyl acetate, washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo. The residue was purified by column chromatography on silica gel eluting with a 0-35% ethyl acetate/n-hexane gradient mixture. A solution of the obtained compound was stirred in the presence of 1.9% palladium on fibroin (200 mg) under hydrogen atmosphere at room temperature for 17 h. The catalyst was removed and the filtrate was concentrated in vacuo. The residue was dissolved in tetrahydrofuran (10 mL) and aqueous sodium hydroxide (8 M, 0.5 mL) was added at room temperature. After 15 h, the reaction mixture was concentrated in vacuo. The residue was dissolved in N,N-dimethylformamide (10 mL) and 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (973 mg, 5.08 mmol) was added at room temperature. After 6 h, 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (155 mg, 1.02 mmol) was added. After 2 h, the reaction mixture was diluted with ethyl acetate, washed with water and brine, dried over sodium sulfate, filtered, and concentrated in vacuo. The residue was purified by column chromatography on silica gel eluting with a 0-35% ethyl acetate/n-hexane gradient mixture to afford the desired product as pale yellow solid (334 mg, 0.801 mmol, 39%).

Provenance & Evidence