反应详情

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.

1. distillationthe cresol was distilled off
2. distillationThe main fraction distilling over at 140° to 143° C/0.06 Torr
3. customwas recrystallised from ethyl acetate
4. customThe identity of the pure substance obtained