Triethylamine → (3S*,4R*)-3-(tert-Butyl-dimethyl-silanyloxymethyl)-4-({isopropyl-[4-methoxy-3-(3-methoxy-propoxy)-benzoyl]-amino}-methyl)-pyrrolidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

A mixture of ((3S,4R)-3-(tert-butyl-dimethyl-silanyloxymethyl)-4-(isopropylamino-methyl)-pyrrolidine-1-carboxylic acid tert-butyl ester (8.9 g, 23.02 mmol), 3-(3-methoxy-propoxy)-4-methoxy-benzoic acid (6.08 g, 25.32 mmol), bis(2-oxo-3-oxazolidinyl)phosphinic chloride (6.45 g, 25.32 mmol) and triethylamine (7.62 mL, 92.07 mmol) in CH2Cl2 (230 mL) is refluxed for 3 h. The reaction is quenched by the addition of an aqueous saturated solution of NaHCO3. The organic layer is separated, and the aqueous phase is extracted 3 times with AcOEt. The combined organic extracts are dried (Na2SO4), and the solvent is removed in vacuo. The crude product is purified by flash chromatography on silica gel (eluent: CH2Cl2/acetone 95:5 to CH2Cl2/MeOH 95:5) to give the title product. TLC, Rf (CH2Cl2/MeOH 95:5)=0.47. MS (LC-MS): 609.4 [M+H]+; tR (HPLC, C18 column, 5-100% CH3CN/H2O/6 min, 100% CH3CN/2 min, CH3CN and H2O containing 0.1% TFA, flow: 1 mL/min): 7.05 min.

Provenance & Evidence