Process for the preparation of sulfonylurea derivatives and intermediates for this process

摘要

The present invention relates to a novel process for preparing sulfonylurea derivatives of formula (I) in a high purity and a high yield characterized in that a compound of formula (VIII) is reacted with 2-amino-4,6-dimethoxypyrimidine of formula (VII): <CHEM> <CHEM> wherein R<1> represents hydrogen, C1-C4 alkyl or phenyl, R<2> represents hydrogen, C1-C4 alkyl, allyl or propargyl and R<3> represents hydrogen, methyl, ethyl or phenyl, and to a process for preparing the compound of formula (VIII) above, which is useful as an intermediate compound for preparing the sulfonylurea derivative of formula (I) and to a novel intermediate compound of formula (VIII) as defined above.