Process for the preparation of alkoxytriazolinones

A semicarbazide derivative of the formula ##STR18## in which R.sup.1 represents hydrogen, or represents alkyl, alkenyl or alkinyl, each of which has up to 6 carbon atoms and each of which is optionally substitued by halogen or C.sub.1 -C.sub.4 -alkoxy, or represents cycloalkyl or cycloalkylalkyl, each of which has 3 to 6 carbon atoms in the cycloalkyl moiety and, if appropriate, 1 to 4 carbon atoms in the alkyl moiety and each of which is optionally substituted by halogen or C.sub.1 -C.sub.4 -alkyl, or represents aryl or arylalkyl, each of which has 6 or 10 carbon atoms in the aryl moiety and, if appropriate, 1 to 4 carbon atoms in the alkyl moiety and each of which is optionally substituted by carboxyl, cyano, nitro, halogen, C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -halogenoalkyl, C.sub.1 -C.sub.4 -alkoxy, C.sub.1 -C.sub.4 -halogenoalkoxy or C.sub.1 -C.sub.4 -alkoxy-carbonyl, and

• R.sup.2 represents alkyl, alkenyl or alkinyl, each of which has up to 6 carbon atoms and each of which is optionally substituted by halogen or C.sub.1 -C.sub.4 -alkoxy, or represents cycloalkyl or cycloalkylalkyl, each of which has 3 to 6 carbon atoms in the cycloalkyl moiety and, if appropriate, 1 to 4 carbon atoms in the alkyl moiety and each of which is optionally substituted by halogen or C.sub.1 -C.sub.4 -alkyl, or represents aryl or arylalkyl, each of which has 6 or 10 carbon atoms in the aryl moiety and, if appropriate, 1 to 4 carbon atoms in the alkyl moiety and each of which is optionally substituted by carboxyl, cyano, nitro, halogen, C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -halogenoalkyl, C.sub.1 -C.sub.4 -alkoxy, C.sub.1 -C.sub.4 -halogenoalkoxy or C.sub.1 -C.sub.4 -alkoxy-carbonyl,
• R.sup.4 represents C.sub.1 -C.sub.4 -alkyl which is optionally substituted by C.sub.1 -C.sub.4 alkoxy, phenoxy, or benzyloxy,
• or a tautomeric compound thereof.