Triphenylphosphine → (R)-4-((R)-1-((5-bromo-1-cyclopropyl-1H-benzo[d]imidazol-7-yl)oxy)ethyl)-1-((R)-1-(4-methoxyphenyl)ethyl)pyrrolidin-2-one

Participants

Reaction Steps

5-bromo-1-cyclopropyl-1H-benzo[d]imidazol-7-ol 2.73 (1.4 g, 5.53 mmol), (R)-4-((S)-1-hydroxyethyl)-1-((R)-1-(4-methoxyphenyl)ethyl)pyrrolidin- 2-one 1.05 (2.04 g, 7.75 mmol), and triphenylphosphine (2.04 g, 7.78 mmol) were taken up in THF (30 mL). Diethyl azodicarboxylate (1.2 ml, 7.65 mmol) was added dropwise over 1 min, and the resulting stirred solution was heated to 40 C. After 1 h, add additional portions of intermediate 1.05 (0.27 g, 1.02 mmol), triphenylphosphine (0.27 g, 1.02 mmol), and diethyl azodicarboxylate (0.15 ml, 0.96 mmol) were added. The mixture was stirred an additional 1.5 h and was then concentrated directly onto silica gel. Purification by silica gel chromatography (20-100% acetone:hexanes) provided (R)-4-((R)-1-((5-bromo-1-cyclopropyl-1H-benzo[d]imidazol-7-yl)oxy)ethyl)-1-((R)-1-(4-methoxyphenyl)ethyl)pyrrolidin-2-one (2.74). LCMS-ESI+ (m/z): [M+H]+ calcd for C25H29BrN3O3: 498.14; found: 498.37.

Provenance & Evidence