1-Piperazinecarboxylic acid, ethyl ester → HCID 178473382, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of Boc-Arg(Pbf)-OH (13.3 g, 25.3 mmol) in DMF (10 mL) was added DIEA (22.0 mL, 126.5 mmol) at room temperature and stirred for 15 min. The reaction mixture was then cooled to ˜5° C. and HATU (11.5 g, 30.3 mmol) was added in portions and stirred for 30 min, followed by the dropwise addition of ethyl-1-piperazine carboxylate (4.0 g, 25.3 mmol) in DMF (30 mL). After 40 min, the reaction mixture was diluted with EtOAc (400 mL) and poured in to H2O (1 L). Extracted with EtOAc (2×400 mL) and washed with H2O (800 mL), 2% H2SO4 (500 mL), H2O (2×800 mL) and brine (800 mL). Organic layer was separated, dried over MgSO4 and solvent removed in vacuo. The resultant oily residue was dried in vacuo to afford compound F (16.4 g, 24.5 mmol) as foamy solid. LC-MS [M+H] 667.2 (C31H50N6O8S+H, calc: 667.8). Compound F was used without further purification.

Provenance & Evidence