Piperidine → Cypate Lys

Participants

Reaction Steps

Fmoc-Lys was attached to Rink amide resin (60 mg, 0.0366 mmol) and the Fmoc was deprotected by piperidine in DMF (20%). A solution of Cypate(129 mg, 5 equiv), HOBT(24.7 mg), and DIC (11.5 mg, 2.5 equiv) in DMF (3 mL) was added into the resin and swirled overnight. After filtered, the resin was washed with DMF and DCM, cleaved with TFA/H2O (95:5) for 3 h, filtered, concentrated, and dried. The crude product was dissolved in 20 mL DCM and added dropwise into a stirred solution of PyBOP (38 mg), HOBT (9.9 mg), and DIEA (18.9 mg) in DCM/DMF(195:5, 200 mL) and the resulting mixture was stirred overnight, concentrated, and purified by HPLC to afforded 1.5 mg of the desired product.

Provenance & Evidence