Methanol → 1-Methyl-5-(methoxycarbonyl-methylene)-hydantoin

Reaction equation

C/[C:2](/[C:8]([O-:10])=O)=[C:3](\C)/[C:4]([O-:6])=[O:5].[CH3:11]O.[CH3:13][NH:14][C:15]([NH2:17])=[O:16]>C1(C)C(O)=CC=CC=1>[CH3:13][N:14]1[C:2](=[CH:3][C:4]([O:6][CH3:11])=[O:5])[C:8](=[O:10])[NH:17][C:15]1=[O:16]

Participants

Procedure

Proceeding in a similar manner to Example 3, 222 g of methyl urea were dissolved in 1000 g of cresol, and 432 g of dimethylmaleate were added. After termination of the reaction during which 92 g of methanol were liberated, and after gas chromatographic analysis showed 95% conversion of the reactants, the cresol was distilled off and the residue fractionated under vacuum. The main fraction distilling over at 140° to 143° C/0.06 Torr was recrystallised from ethyl acetate. The identity of the pure substance obtained, which melted at 100° C, could be confirmed by the IR and NMR spectra and elementary analysis.