Ethyl chloroformate → [Ethoxycarbonyl-(2-thiophen-2-yl-ethyl)-amino]acetic acid ethyl ester

Participants

Reaction Steps

2-Thiophen-2-yl-ethylamine (21.0 g, 165 mmol) was stirred in 1 liter of DCM. Ethyl glyoxylate (165 mmol, 50% in toluene) was added followed by 50 μL HOAc. The reaction was stirred for 10 minutes after which time NaBH(OAc)3 (214 mmol, 45 g) was added slowly. After 15 minutes HOAc was added (214 mmol) and the reaction was stirred for 20 minutes. The reaction was concentrated and the crude material was redissolved in 500 mL each of THF and water. NaHCO3 (42 g, 500 mmol) was added followed by ethyl chloroformate (21 mL, 214 mmol). Saturated NaHCO3 was added slowly to the reaction until the gas evolution was minimal. After stirring overnight, the reaction was diluted with EtOAc (400 mL). The product was extracted 2× into EtOAc, dried over MgSO4 and concentrated to the sub-title product as a dark oil.

Provenance & Evidence