Method of producing nitroguanidine- and nitroenamine derivatives

A process for the preparation of a compound of the formula

• wherein
• R1 is hydrogen or C1-C4-alkyl;
• R6 is hydrogen, C1-C8-alkyl, aryl or benzyl;
• R2 is hydrogen, C1-C8-alkyl, C3-C6-cycloalkyl, or a group of the formula —N(R3)R4;
• or R2 and R6 together are a group —CH2—CH2—S—, the ethylene group of which is bonded to the nitrogen atom shown in the formula I;
• R3 and R4, independently of one another, are hydrogen, C1-C4-alkyl, C3-C6-cycloalkyl or a group —CH2B;
• or R3 and R8 together are —CH2—CH2—, —CH2—CH2—CH2—, —CH2—O—CH2—, —CH2—S—CH2— or —CH2—N(R5)—CH2—;
• R5 is methyl;
• X is N—CN, CH—CN, CH—NO2 or N—NO2;
• A is an aromatic or non-aromatic, monocyclic or bicyclic, heterocyclic group, which is unsubstituted or—depending on the substitution possibilities of the ring system—mono- to penta-substituted by substituents, selected from the group consisting of halogen, C1-C3-alkyl, C1-C3-alkoxy, halogen-C1-C3-alkyl, halogen-C1-C3-alkoxy, cyclopropyl, halogencyclopropyl, C2-C3-alkenyl, C2-C3-alkynyl, halogen-C2-C3-alkenyl, halogen-C2-C3-alkynyl, C1-C3-alkylthio, halogen-C1-C3-alkylthio, allyloxy, propargyloxy, allylthio, propargylthio, halogenallyloxy, halogenallylthio, cyano and nitro;
• and
• B is a phenyl, 3-pyridyl or thiazolyl group which is optionally substituted by one to three substituents, selected from the group consisting of C1-C3-alkyl, halogen-C1-C3-alkyl, cyclopropyl, halogencyclopropyl, C2-C3-alkenyl, C2-C3-alkynyl, C1-C3-alkoxy, halogen-C2-C3-alkenyl, halogen-C2-C3-alkynyl, halogen-C1-C3-alkoxy, C1-C3-alkylthio, halogen-C1-C3-alkylthio, allyloxy, propargyloxy, allylthio, propargylthio, halogenallyloxy, halogenallylthio, halogen, cyano and nitro,
• which process is characterised in that a compound of the formula
• wherein R2, R6 and X are as defined hereinbefore for the formula I, is reacted in the presence of a solvent or diluent, of a phase transfer catalyst and of a base with a compound of the formula
• wherein A and R1 are as defined hereinbefore for the formula I, and Q is a leaving group, the said solvent or diluent being an ester of carbonic acid.