[C:1]([OH:9])(=[O:8])[C:2]([CH2:4][C:5]([OH:7])=[O:6])=[CH2:3].CN.C(C1C[N:18](C)[C:17](=O)C1)(O)=O>O>[C:1]([OH:9])(=[O:8])[C:2]([CH2:4][C:5]([OH:7])=[O:6])=[CH2:3].[CH3:17][NH2:18]Itaconic acid (100 g, 0.78 mol) and methylamine (41% in water, 60.0 g based on the aqueous solution, 0.80 mol, 1.0 equivalent) were mixed as in example 8. The suspension was heated to boiling under reflux at standard pressure for 1 hour (in the course of which the boiling point rises to approx. 115° C.). This dissolved the solids completely. Cooling to ambient temperature formed a precipitate. NMR analysis of the homogeneous solution and of the precipitated crystals (solvent: D2O) showed that the itaconic acid:4-carboxy-1-methylpyrrolidone ratio in both phases was 0:100. The 4-carboxy-1-methylpyrrolidone product was purified by recrystallization from ethyl acetate and was obtained in the form of colorless crystals (yield: 59 g, 67%).
Loading…