Trimethylphosphine → Triethyl [1-[(4-chlorophenyl)methyl]-2-(1-methylethyl)-4,5,6,7-tetrahydro-1H-benzimidazol-7-yl]methanetricarboxylate

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of Intermediate 58 (99 mg) and triethylmethanetricarboxylate (0.14 mL) in anhydrous Toluene (3 mL) and anhydrous Tetrahydrofuran (THF) (3.00 mL) under a nitrogen atmosphere was added trimethylphosphine, 1M in Toluene (0.650 mL). The reaction was then cooled to −78° C. and diisopropyl azodicarboxylate (0.13 mL) added dropwise via syringe over 1 min. The reaction was stirred at −78° C. under an atmosphere of nitrogen for 90 mins before being allowed to warm to ambient temperature and stirred for a further 1 h. The reaction was concentrated in vacuo. The residue was taken up in dichloromethane (40 mL) and washed with water (40 mL), dried (hydrophobic frit) and concentrated in vacuo. The sample was loaded in dichloromethane and purified on silica using a 0-100% ethyl acetate-cyclohexane gradient. The appropriate fractions were combined and evaporated in vacuo to give the required product (139 mg). LC/MS MH+ 519, Rt 2.15 min (5 min run).

Provenance & Evidence