Preparation of hydantoins by reacting esters of ethylene-1,2-dicarboxylic acids and ureas and thioureas

Claim 1

A process for preparing a compound of the formula ##STR5## wherein R is alkyl having one to eighteen carbon atoms; R 1 and R 2 are hydrogen or alkyl having 1 to 18 carbon atoms; R 3 is monofunctional or polyfunctional and is selected from the group consisting of hydrogen; alkyl and cycloalkyl each having up to 18 carbon atoms; said alkyl and cycloalkyl substituted with halogen or hydroxy; aryl and aralkyl each having up to 16 carbon atoms; said aryl substituted with nitro, halogen, lower alkyl, lower alkoxy, or hydroxy; furan; pyridine; thiophene; imidazole; pyrimidine and piperazine; R 4 is monofunctional or polyfunctional and is selected from the group consisting of hydrogen; alkyl and cycloalkyl each having up to eighteen carbon atoms; said alkyl and said cycloalkyl substituted by halogen or hydroxy; aryl and aralkyl each having up to 16 carbon atoms; said aryl substituted with nitro, halogen, lower alkyl, lower alkoxy or hydroxy; furan; pyridine; thiophene; imidazole; pyrimidine and piperazine; X is O or S and n is from 1 to 30, said process comprising reacting a compound of the formula ##STR6## with a compound of the formula ##STR7## at a temperature of from 80° to 250° C in a single-stage reaction.