2-Ethylhexanoic Acid → 1-Benzyl-3-phenyl-5-(methoxycarbonylmethylene)-hydantoin

Reaction equation

[C:1]1([NH:7][C:8]([NH:10][CH2:11][C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)=[O:9])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.C(C(CCCC)C(O)=O)C.[C:28](OC)(=[O:35])/[CH:29]=[CH:30]\[C:31]([O:33][CH3:34])=[O:32]>ClC1C=CC=CC=1Cl>[CH2:11]([N:10]1[C:29](=[CH:30][C:31]([O:33][CH3:34])=[O:32])[C:28](=[O:35])[N:7]([C:1]2[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=2)[C:8]1=[O:9])[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1

Participants

Procedure

113 g of N-phenyl-N'-benzyl-urea were dissolved in 1000 g of o-dichlorobenzene; the solution was made acid with 2-ethyl-hexanoic acid and reacted with 72 g of dimethyl maleate. After a reaction time of 6 hours at 175° C, the solvent was distilled off and the residue triturated with ether. The product separated by suction filtration can be obtained pure by recrystallisation from toluene. The white crystals obtained have a melting point of 130° C and their structure was demonstrated by the IR and NMR spectra and elementary analysis.