Reaction #2840

Reaction equation

1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride

(S)-Boc-Diaminobutyric acid

triethylamine

1-hydroxybenzotriazole hydrate

→

title compound

Yield 85.2%

(2-Oxo-pyrrolidin-3-(S)-yl)-carbamic acid tert-butyl ester

Yield 85.2%

Solvents

THF

Conditions

Workup

1. 1
   FiltrationAfter this time, the solution is filtered
2. 2
   Concentrationthe collected liquid is concentrated
3. 3
   OtherThe crude product is purified by column chromatography
4. 4
   Washeluting with a gradient of 1% MeOH/CH2Cl2 to 3% MeOH/CH2Cl2

Procedure

(S)-Boc-Diaminobutyric acid (25 g, 115 mmol), triethylamine (35 g, 344 mmol), and 1-hydroxybenzotriazole hydrate (19.3 g, 143 mmol) are dissolved in 300 mL of THF. 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (27.4 g, 143 mmol) is added to the solution. The solution is heated at 60° C. over 15 min. A white precipitate forms and the solution is kept at 60° C. for 4 h. After this time, the solution is filtered and the collected liquid is concentrated. The crude product is purified by column chromatography eluting with a gradient of 1% MeOH/CH2Cl2 to 3% MeOH/CH2Cl2 to afford the title compound (19.6 g, 98 mmol) as a white solid.

Source