Pyridine → (3R*,5S*)-3-{Cyclopropyl-[1-(3-methoxy-propyl)-1H-indol-3-ylmethyl]-carbamoyl}-5-(2-nitro-benzenesulfonylamino)-piperidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a solution of (3S*,5R*)-3-Amino-5-{cyclopropyl-[1-(3-methoxy-propyl)-1H-indol-3-ylmethyl]-carbamoyl}-piperidine-1-carboxylic acid tert-butyl ester (400 mg, 0.83 mmol) in CH2Cl2 (1 mL) are added pyridine (1 mL) and o-nitrobenzenesulfonyl chloride (274 mg, 1.2 mmol) at 0° C., then the mixture is stirred at room temperature. After 20 h, the reaction mixture is quenched by H2O (30 mL) and extracted with EtOAc (100 mL). The organic layer is successively washed with 5% aqueous KHSO4, H2O, and brine, then dried over Na2SO4 and concentrated in reduced pressure. The residue is purified by silica gel column chromatography to afford the title compound as brown amorphous material. MS: 670 [M+H]+; tR (HPLC, ACQUITY UPLC™ BEH C18 1.7 μm, 50×2.1 mm; 5% CH3CN+0.1% TFA/H2O+0.1% TFA for 0.5 min then 5-100% CH3CN+0.1% TFA/H2O+0.1% TFA for 5 min then 100% CH3CN+0.1% TFA for 1.5 min, flow 0.5 ml/min): 4.14 min.

Provenance & Evidence