Process for preparing phenylisopropylurea compounds.

摘要

A new and improved process for making phenylisopropylurea derivatives having the formula:
<Chemistry id="chema01" num="0001"><Image id="ia01" he="23" wi="44" file="IMGA0001.TIF" imgContent="chem" imgFormat="TIFF" inline="no" /></Chemistry>
wherein R' is selected from hydrogen, halogen, alkyl, alkenyl, haloalkyl or R<Sup>2</Sup> groups and R<Sup>2</Sup> is selected from phenyl, alkyl-substituted phenyl alkoxy-substituted phenyl or haloalkyl-substituted phenyl is disclosed. The process comprises reacting a substituted urea of the formula:
<Chemistry id="chema02" num="0002"><Image id="ia02" he="17" wi="33" file="IMGA0002.TIF" imgContent="chem" imgFormat="TIFF" inline="no" /></Chemistry>
with an alkenyl aromatic compound of the formula:
<Chemistry id="chema03" num="0003"><Image id="ia03" he="30" wi="34" file="IMGA0003.TIF" imgContent="chem" imgFormat="TIFF" inline="no" /></Chemistry>
in a polar aprotic solvent, in the presence of an acid catalyst, preferably, sulfuric acid, substituted sulfonic acids or Lewis acids, and stirring the reaction mixture at a temperature of about 20 to 80°C until formation of the precipitated phenylisopropylurea derivative is substantially complete.