反应详情

5-Hydantoin acetic acid (20.57 g, 0.130 mol) in MeOH (210 mL) was treated with conc. H2SO4 (7 mL) and heated to reflux under N2 for 2.5 h. The resultant clear solution was cooled and the solvent removed in vacuo to give an oil which was diluted with water (65 mL) and extracted 4 times with EtOAc. The organic layer was dried (MgSO4) and the solvent removed in vacuo to afford 19.81 g (88%) of (2,5-dioxo-imidazolidin-4-yl)-acetic acid methyl ester. MS (ES+) Calc'd for C6H9N2O4 (M+1) 173. Found m/z 173 (100%). 1H NMR.

1. temperatureheated
2. temperatureto reflux under N2 for 2.5 h
3. temperatureThe resultant clear solution was cooled
4. customthe solvent removed in vacuo
5. customto give an oil which
6. extractionextracted 4 times with EtOAc
7. dry with materialThe organic layer was dried (MgSO4)
8. customthe solvent removed in vacuo