Phenylacetyl chloride → (3R,4R)-3-({Isopropyl-[4-methoxy-3-(3-methoxy-propoxy)-benzoyl]-amino}-methyl)-4-[(methyl-phenylacetyl-amino)-methyl]-pyrrolidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution of (3R,4R)-3-({isopropyl-[4-methoxy-3-(3-methoxy-propoxy)-benzoyl]-amino}-methyl)-4-methylaminomethyl-pyrrolidine-1-carboxylic acid tert-butyl ester (2 g, 3.35 mmol) in CH2Cl2 (25 mL), phenylacetyl chloride (0.53 mL, 4.02 mmol) and triethylamine (0.56 mL, 4.02 mmol) are added under N2 atmosphere at 0° C. The mixture is stirred 30 min at 0° C., then allowed to reach RT and further stirred for 1 h. The reaction mixture is diluted with CH2Cl2 and poured into an aqueous saturated solution of NaHCO3. The organic layer is separated, and the aqueous one is extracted twice with CH2Cl2. The combined organic extracts are dried over Na2SO4, filtered and concentrated. The crude product is purified by flash chromatography on silica gel (eluent: c-hexane/AcOEt 20:80 to 0:100) to give the title compound. TLC, Rf (CH2Cl2/MeOH 95:5)=0.4. MS (LC-MS): 526 [M-Boc+H]+; tR (HPLC, Macherey-Nagel Nucleosil C18 column, 10-100% CH3CN/H2O/5 min, 100% CH3CN/3 min, CH3CN and H2O containing 0.1% TFA, flow: 1.5 ml/min): 5.71 min.

Provenance & Evidence