Trifluoroacetic acid → Methyl (2,3-dioxopiperazin-1-YL)acetate
Reaction equation
COC1C=C(OC)C=CC=1C[N:6]1[CH2:11][CH2:10][N:9]([CH2:12][C:13]([O:15][CH3:16])=[O:14])[C:8](=[O:17])[C:7]1=[O:18].FC(F)(F)C(O)=O.C1(OC)C=CC=CC=1>>[O:17]=[C:8]1[C:7](=[O:18])[NH:6][CH2:11][CH2:10][N:9]1[CH2:12][C:13]([O:15][CH3:16])=[O:14]Participants
4
Procedure
A mixture of 10.5 g of methyl [4-(2,4-dimethoxybenzyl)-2,3-dioxopiperazin-1-yl]acetate, 42 ml of trifluoroacetic acid and 21 ml of anisole was refluxed for 4 hours. The reaction mixture was cooled to room temperature and then distilled under reduced pressure to remove the solvent. The resulting residue was purified by a silica gel column chromatography (eluent; chloroform: methanol=6:1) to obtain 4.5 g of methyl (2,3-dioxopiperazin-1-yl)acetate as colorless crystals.