Process for the selective preparation of fluorinated aromatic amines and fluorinated aromatic amines with particularly low contents of defluorinated portions

摘要

The catalytic hydrogenation of fluorinated aromatic nitro cpds. (I) is carried out in the liq. phase and in the presence of a catalyst contg. at least one metal or metal cpd. chosen from nickel, cobalt, and the noble metals and in the presence of a sulphur cpd. of formula (II). R1-S(O)n-R2 (II); R1 = 1-12C alkyl, hydroxy(1-12C)-alkyl, carboxy(1-12C)alkyl or Ph; R2 H or CO(1-12C)alkyl, 1-12C alkyl, hydroxy(1-12C)-alkyl, carboxy(1-12C)alkyl or Ph; or R1+R2 = CH=CHCH=CH, (CH2)4, (CH2)5 or (CH2)2X(CH2)2; X = O or S; n = 0-1. Also claimed are fluorinated aromatic amines of formula (III) of purity >96% and a content of defluorinated prods. <0.1%. R3-R6 = 1-10C alkyl, 6-10C aryl, 7-14C aralkyl, 6-10C arylsulphonyl (all opt. mono- or di-substd. with OH, amino, CN or COOH), H, COOH, halogen, NH2, NO2, OH, CCl3 or CF3. Also claimed is 5-fluoroanthranilic acid of purity >99% and content of defluorinated prods. <0.01%.