Pivaloyl chloride → HCID 57870340, compound

Participants

Reaction Steps

A solution of (3S,5R)-3-Benzylamino-5-{cyclopropyl-[1-(3-methoxy-propyl)-1H-indol-3-ylmethyl]-carbamoyl}-piperidine-1-carboxylic acid 9H-fluoren-9-ylmethyl ester (68.5 mg, 0.098 mmol) in CH2Cl2 is treated with i-Pr2NEt (40.2 μL, 0.235 mmol) and pivaloylchloride (23.9 μL, 0.196 mmol). The solution is stirred at room temperature for 18 h. Additional i-Pr2NEt (20 μL, 0.12 mmol) and pivaloylchloride (12 μL, 0.095 mmol) are added and stirring is continued for 9 h. The reaction mixture is partitioned between EtOAc and 1 M NaHCO3, the organic layer is washed with 1 M NaHCO3 and brine, dried over MgSO4, filtered and concentrated in vacuo. The residue is dissolved in THF/piperidine (5:1) (6 mL), the solution is stirred at room temperature for 2.5 h and then concentrated in vacuo. The crude product is purified by RP-HPLC to afford the title compound. MS: 559 [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): 3.40 min.

Provenance & Evidence