Reaction #358803

Reaction equation

benzyliminodiacetic acid

triethylamine

trifluoroacetamide

1-[3(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride

→

4-benzyl-piperazine-2,6-dione

Yield 73.1%

Solvents

CH2Cl2

Conditions

Workup

1. 1
   OtherThe reaction mixture is quenched with cold H2O
2. 2
   Extractionextracted with CH2Cl2
3. 3
   WashThe combined extracts are washed with H2O brine
4. 4
   Dryingdried over MgSO4
5. 5
   Concentrationconcentrated under reduced pressure
6. 6
   OtherThe residue is purified by silica gel column chromatography (eluent: n-Hexane:AcOEt=2:1)

Procedure

To a suspensiopn of 15 g (67 mmoles) of benzyliminodiacetic acid in 300 ml of CH2Cl2, 28 ml (201 mmoles) of triethylamine, 21.77 g (161 mmoles) of 1H-hydroxybenztriazole and 10.6 g (94 mmoles) of trifluoroacetamide are successively added and then 28.34 g (147.8 mmoles) of 1-[3(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride is added at 0° C. The reaction mixture is allowed to warm to ambient temperature and stirred for 18 hours. The reaction mixture is quenched with cold H2O and extracted with CH2Cl2. The combined extracts are washed with H2O brine, dried over MgSO4 and concentrated under reduced pressure. The residue is purified by silica gel column chromatography (eluent: n-Hexane:AcOEt=2:1) to give 10 g of desired 4-benzyl-piperazine-2,6-dione in 73% yield.

Source