Starting materials for prepartion of sulfonylurea derivatives and

Abstract

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 sulfonylchloride of formula (V) is reacted with 2-amino-4,6-dimethoxypyrimidine of formula (VII) in the presence of a metal cyanate and an organic base catalyst or a compound of formula (VIII) is reacted with 2-amino-4,6-dimethoxypyrimidine of formula (VII): ##STR1## wherein R.sup.1 represents hydrogen, C.sub.1 -C.sub.4 alkyl or phenyl, R.sup.2 represents hydrogen, C.sub.1 -C.sub.4 alkyl, allyl or propargyl and R.sup.3 represents hydrogen, methyl, ethyl or phenyl, and to a process for preparing the sulfonylchloride compound of formula (V) above and the compound of formula (VIII) above, both of which are 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.