TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The metal catalyst comprises palladium, platinum, nickel or cobalt. Preferred Method: The step (A) makes use of catalytic amount of metal iodide, where the metal iodide is used in an amount of 0.1-20 mole%, based on (III); and 1 or 2 molar equivalents of hypophosphorous acid or sodium hypophosphite, based on (III). The step (B) makes use of 0.01-50 wt.% the metal catalyst, based on (IV).    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The step (B) is carried out at a temperature of 20-150 degrees C. The step (A) is carried out at a temperature of 0-150 degrees C. The step (A) is carried out in an organic solvent in presence of water. The step (A) makes use of hypophosphorous acid or sodium hypophosphite in presence of water. The amount of water used in the step (A) is at least 0.15 wt.%, based on the total weight of the organic solvent and water. Water is provided by sodium hypophosphite in the form of its hydrate. (III) are used in the step (A) in an amount of at least 0.6 mol/liter.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: (IVa) comprise 1,1'-disulfanediyl-bis(4-fluoro-2-methyl-5-nitrobenzene), 1,1'-disulfanediylbis(2,4-dichloro-5-nitrobenzene), 1,1'-disulfanediylbis(2-fluoro-4-methyl-5-nitrobenzene), 1,1'-disulfanediylbis(4-fluoro-2-methyl-3-nitrobenzene), 1-fluoro-4-((4-fluoro-2-methyl-5-nitrophenyl)-disulfanyl)-3-methyl-2-nitrobenzene, 1-fluoro-4-((2-fluoro-4-methyl-5-nitrophenyl)-disulfanyl)-5-methyl-2-nitrobenzene or 1-fluoro-4-((2-fluoro-4-methyl-5-nitrophenyl)-disulfanyl)-3-methyl-2-nitrobenzene. (IIa) comprise 5-amino-2,4-dichlorobenzenethiol, 5-amino-2-fluoro-4-methylbenzenethiol or 3-amino-2-fluoro-4-methylbenzenethiol. (V) comprise 4-fluoro-2-methyl-5-nitrobenzenethiol, 2,4-dimethyl-5-nitrobenzenethiol, 2,4-difluoro-5-nitrobenzenethiol, 4-chloro-2-methyl-5-nitrobenzenethiol, 2-chloro-4-methyl-5-nitrobenzenethiol or 2-fluoro-4-methyl-5-nitrobenzenethiol. SPECIFIC COMPOUNDS - 7 Specific compounds (I) are prepared e.g. 3,3'-disulfanediylbis(6-fluoro-4-methylaniline) of formula (Ia), 3,3'-disulfanediylbis(4,6-dichloroaniline), 3,3'-disulfanediylbis(4-fluoro-6-methylaniline), 3,3'-disulfanediylbis(2-fluoro-6-methylaniline), 3-((5-amino-4-fluoro-2-methylphenyl)disulfanyl)-6-fluoro-2-methylaniline, 5-((5-amino-2-fluoro-4-methylphenyl)-disulfanyl)-2-fluoro-4-methylaniline, 3-((5-amino-2-fluoro-4-methylphenyl)-disulfanyl)-6-fluoro-2-methylaniline.    EXAMPLE - Solution of 1.96 g 1,1'-disulfanediylbis(4-fluoro-2-methyl-5-nitrobenzene) in 50 ml tetrahydrofuran was hydrogenated at 0.4 g Raney (RTM: Catalyst) cobalt for 19 hours at 65 degrees C and 30 bar hydrogen pressure. Then the obtained reaction solution was filtered. Then the solvent was evaporated to obtain (Ia).