反应详情

63.9 g (0.25 mol) of 3-chloro-2,4,5-trifluoro-6-nitrobenzoic acid and 15 g of Raney nickel are suspended in 450 ml of ethanol. Hydrogenation is carried out at 10°-15° C. under a hydrogen pressure of 5-10 bar until the uptake of hydrogen has ended. The crude reaction mixture is poured onto 1 l of water. The carboxylic acid which has precipitated is dissolved by addition of 10% strength sodium hydroxide solution. When the catalyst has been filtered off with suction, a pH of 2-3 is established by addition of half-concentrated hydrochloric acid. The precipitate is filtered off with suction, washed with water and dried over KOH in a desiccator.

1. customis carried out at 10°-15° C. under a hydrogen
2. customThe crude reaction mixture
3. customThe carboxylic acid which has precipitated
4. dissolutionis dissolved by addition of 10% strength sodium hydroxide solution
5. filtrationWhen the catalyst has been filtered off with suction
6. additiona pH of 2-3 is established by addition of half-concentrated hydrochloric acid
7. filtrationThe precipitate is filtered off with suction
8. washwashed with water
9. dry with materialdried over KOH in a desiccator