Process for preparing substituted aryluracils

Process for preparing substituted aryluracils of the general formula (I) ##STR11## in which R.sup.1 represents hydrogen or halogen,

• R.sup.2 represents cyano, halogen, thiocarbamoyl or optionally substituted alkyl,
• R.sup.3 represents respectively optionally substituted alkyl, alkenyl, alkinyl, cycloalkyl, cycloalkylalkyl, aryl or arylalkyl,
• R.sup.4 represents hydrogen, halogen or optionally substituted alkyl and
• R.sup.5 represents optionally substituted alkyl,
• characterized in that aminoalkenoic esters of the general formula (II) ##STR12## in which R.sup.4 and R.sup.5 are each as defined above and
• R represents alkyl, aryl or arylalkyl,
• are reacted with arylurethanes (arylcarbamates) of the general formula (III) ##STR13## in which R.sup.1 and R.sup.2 are each as defined above,
• R represents alkyl, aryl or arylalkyl and
• X represents halogen,
• in the presence of a metal alkoxide or a metal carbonate as acid binder and in the presence of an aprotic polar solvent at temperatures between -20.degree. C. and +150.degree. C. ("step one")
• and the resulting aryluracil intermediates of the general formula (Ia) ##STR14## in which R.sup.1, R.sup.2, R.sup.4, R.sup.5 and X are each as defined above, are then--if appropriate after intermediary isolation--reacted with sulfonamides of the general formula (IV)
• H.sub.2 N--SO.sub.2 --R.sup.3, (IV)
• in which
• R.sup.3 is as defined above,
• in the presence of a metal carbonate as acid binder and in the presence of an aprotic polar solvent at temperatures between 20.degree. C. and 200.degree. C., if appropriate under an atmosphere of inert gas ("step 2").