Method for producing (hetero)aromatic hydroxylamines

A process for the preparation of a (hetero)aromatic hydroxylamine compound of formula I

• wherein
• R1 is a group A-B, where
• A is —O—, —CH2-, —O—CH2-, —CH2-O—, —CH2-O—CO—, —CH═CH—, —CH═N—O—, —CH2-O—N═C(Ra)- or a single bond,
• B is phenyl, naphthyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, pyrazolyl, imidazolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, 1,2,4-triazolyl, 1,2,3-triazolyl, furanyl, thienyl, pyrrolyl or C3-C7-cycloalkyl, where B may be substituted by 1-3 substituents Ri,
• Ri is hydrogen, halogen, cyano, C1-C4-alkyl, C1-C4-haloalkyl, C1-C4-alkoxy, C1-C4-haloalkoxy, C1-C4-alkylthio, C1-C4-alkylcarbonyl, C1-C4-alkyl-C(Rd)=N—O—C1-C4-alkylene, C1-C4-alkoxycarbonyl, C1-C4-alkylaminocarbonyl, C1-C4-dialkylaminocarbonyl, C1-C4alkylcarbonylamino, C1-C4-alkylcarbonyl-C1-C4-alkylamino or phenyl which itself may be substituted by halogen or C1-C4-alkyl,
• Ra is hydrogen, halogen, cyano, C1-C4-alkyl, C1-C4-alkoxy, C1-C4-alkylthio, cyclopropyl or trifluoromethyl,
• Rd is hydrogen, C1-C4-alkyl, C2-C4-alkenyl, or C2-C4-alkynyl,
• R2 is halogen, C1-C4-alkyl, C1-C4-haloalkyl or C1-C4-alkoxycarbonyl,
• X is CH and
• n is 0, 1, 2 or 3, where the radicals R2 are identical or different when n is greater than 1, which process comprises hydrogenating a (hetero)aromatic nitro compound of formula II
• in the presence of a hydrogenation catalyst, wherein the hydrogenation is carried out in a mixture comprising an inert, aprotic solvent and a C1-C4-alkylamine.