glass autoclave 3 bar of hydrogen were forced in while stirring intensively after 6 hours the reaction had ended and analysis by liquid chromatography showed the following result 33 4 g 0 20 mol of 3 nitro benzoic acid 440 ml of water 30 ml of methanol 34 0 g 0 347 mol of sulphuric acid and 1 5 g of pt 5 c were heated to 120 u00b0 c in a 1 3 l enamel autoclave 3 bar of hydrogen were forced in while stirring intensively after 75 minutes the reaction had ended and analysis by liquid chromatography showed the following result 33 4 g 0 20 mol of 3 nitro benzoic acid 470 ml of water 34 0 g 0 347 mol of sulphuric acid and 1 5 g of pt 5 c were heated to 120 u00b0 c in a 1 3 l enamel autoclave 3 bar of hydrogen were forced in while stirring intensively after 90 minutes the reaction had ended and analysis by liquid chromatography showed the following result a mixture of 28 20 g 0 20 mol of 2 fluoro nitrobenzene 450 ml of water 20 ml of ethanol and 27 00 g 0 28 mol of sulphuric acid was heated to 120 u00b0 c in a closed enamel.