| 摘要 |
The yield of hexanitrostilbene from the reaction of 2,4,6-trinitrotoluene and an alkali metal or alkaline earth metal hypochlorite, in an aqueous organic solvent, is improved by adjusting the pH of the reaction mixture to within the range 9.5 to 11.0 and then maintaining the pH within that range by the progressive addition of an alkali metal hydroxide. The pH is preferably kept above 9.75, especially from 10 to 10.5. In a preferred embodiment, 2,4,6-trinitrotoluene is contacted with aqueous sodium hypochlorite (containing from 4 to 10% (w/v) chlorine) in tetrahydrofuran-methanol. After an initial reaction period of between 0.5 to 3 minutes, an inorganic acid, especially sulphuric or hydrochloric acid, is added to the reaction mixture to bring its pH within the required range, and then an alkali metal hydroxide, especially sodium or potassium hydroxide, is added continuously to maintain the pH within that range. The controlled reaction proceeds for 1 to 2 hours at -5 DEG to 25 DEG C., preferably 10 DEG to 16 DEG C. Well-known methods of isolation then afford hexanitrostilbene in yields of about 50%.
|
