Process for the preparation of nitroguanidine derivatives

A process for the preparation of a compound of the formula I ##STR414## in which R.sub.1 is hydrogen or C.sub.1 -C.sub.4 alkyl,

• R.sub.2 is hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.3 -C.sub.6 cycloalkyl or a radical --CH.sub.2 B;
• A is an unsubstituted or mono- to tetrasubstituted aromatic or non-aromatic, monocyclic or bicyclic heterocyclic radical, which may contain one or two substituents selected from the group consisting of C.sub.1 -C.sub.3 haloalkyl having 1 to 7 halogen atoms, cyclopropyl, halocyclopropyl having 1 to 3 halogen atoms, C.sub.2 -C.sub.3 alkenyl, C.sub.2 -C.sub.3 alkynyl, C.sub.2 -C.sub.3 haloalkenyl and C.sub.2 -C.sub.3 haloalkylnyl having 1 to 4 halogen atoms, C.sub.1 -C.sub.3 haloalkoxy having 1 to 7 halogen atoms, C.sub.1 -C.sub.3 alkylthio, C.sub.1 -C.sub.3 haloalkylthio having 1 to 7 halogen atoms, allyloxy, propargyloxy, allylthio, propargylthio, haloallyloxy, haloallylthio, cyano and nitro;
• and one to four substituents selected from the group consisting of C.sub.1 -C.sub.3 alkyl, C.sub.1 -C.sub.3 alkoxy and halogen;
• and
• B is phenyl, cyanophenyl, nitrophenyl, halophenyl having 1 to 3 halogen atoms, phenyl substituted by C.sub.1 -C.sub.3 alkyl, C.sub.1 -C.sub.3 haloalkyl having 1 to 7 halogen atoms, C.sub.1 -C.sub.3 alkoxy or C.sub.1 -C.sub.3 haloalkoxy having 1 to 7 halogen atoms, 3-pyridyl, 5-thiazolyl, 5-thiazolyl substituted by one or two substituents selected from the group consisting of C.sub.1 -C.sub.3 alkyl, C.sub.1 -C.sub.3 haloalkyl having 1 to 7 halogen atoms, cyclopropyl, halocyclopropyl, C.sub.2 -C.sub.3 alkenyl, C.sub.2 -C.sub.3 alkynyl, C.sub.1 -C.sub.3 alkoxy, C.sub.2 -C.sub.3 haloalkenyl and C.sub.2 -C.sub.3 haloalkynyl having 1 to 4 halogen atoms, C.sub.1 -C.sub.3 haloalkoxy having 1 to 7 halogen atoms, C.sub.1 -C.sub.3 alkylthio, C.sub.1 -C.sub.3 haloalkylthio having 1 to 7 halogen atoms, allyloxy, propargyloxy, allylthio, propargylthio, haloallyloxy, haloallylthio, halogen, cyano and nitro, or 3-pyridyl substituted by one or two radicals selected from the group consisting of C.sub.1 -C.sub.3 haloalkyl having 1 to 7 halogen atoms, cyclopropyl, halocyclopropyl, C.sub.2 -C.sub.3 alkenyl, C.sub.2 -C.sub.3 alkynyl, C.sub.2 -C.sub.3 haloalkenyl and C.sub.2 -C.sub.3 haloalkynyl having 1 to 4 halogen atoms, C.sub.1 -C.sub.3 haloalkoxy having 1 to 7 halogen atoms, C.sub.1 -C.sub.3 alkylthio, C.sub.1 -C.sub.3 haloalkylthio having 1 to 7 halogen atoms, allyloxy, propargyloxy, allylthio, propargylthio, haloallyloxy, haloallylthio, cyano and nitro or by one to four radicals selected from the group consisting of C.sub.1 -C.sub.3 alkyl, C.sub.1 -C.sub.3 alkoxy and halogen,
• which comprises hydrolyzing a compound of the formula II ##STR415## in which R.sub.3 is C.sub.1 -C.sub.10 alkyl, C.sub.3 -C.sub.6 cycloalkyl, C.sub.1 -C.sub.10 alkyl substituted by 1-12 radicals selected from the group consisting of halogen, hydroxyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 haloalkoxy having 1 to 9 halogen atoms, di-(C.sub.1 -C.sub.4 alkyl)amino and C.sub.1 -C.sub.5 alkoxycarbonyl, C.sub.3 -C.sub.6 cycloalkyl substituted by 1-4 C.sub.1 -C.sub.4 alkyl radicals or halogen atoms, phenyl or benzyl, or phenyl or benzyl substituted by 1-3 ring substitutents selected from the group consisting of halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 haloalkyl having 1 to 9 halogen atoms, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 haloalkoxy having 1 to 9 halogen atoms, C.sub.1 -C.sub.4 alkylthio, nitro and cyano.