反应详情

温度

220 °C

800 g of 95% strength sulfuric acid are initially taken and 200 g of 89.4% strength perylene-3,4,9,10-tetracarboxylic acid diimide are introduced at room temperature. The temperature of the mixture is then raised to 220° C. and maintained at this level for two hours. The mixture is then allowed to cool to room temperature and the precipitate which has been formed is filtered off with suction and washed first with 280 g of 80% strength sulfuric acid and then with water until it is neutral. Drying at 80° C. gives 170.9 g of crude perylene-3,4,9,10-tetracarboxylic dianhydride. This is introduced, with exclusion of light, into a solution composed of six liters of water and 140 g of 85% strength potassium hydroxide. While blanketed with nitrogen, the solution is heated to 80°-90° C. and stirring is continued for a further 90 minutes at this temperature. The mixture is then allowed to cool to 25° C., the pH is adjusted to a value of 8-9 and the solid residue is filtered off and washed with 100 ml of water. (The residue is 35.6 g of perylene-3,4,9,10-tetracarboxylic acid diimide which has been only half-saponified, i.e. perylene-3,4,9,10-tetracarboxylic acid monoanhydride-monoimide, and this is expediently added to the next batch.) 120 g of 85% strength potassium hydroxide are introduced into the filtrate, with exclusion of light, and the mixture is then blanketed with nitrogen. After a further hour's stirring at 25° C., a solution of 120 g of iron(II) sulfate and 600 ml of water is added dropwise, the mixture is stirred for a further hour at 25° C. and clarified and the filtrate is then added dropwise to 600 g of concentrated hydrochloric acid, the mixture is kept at 80°-90° C. for one hour and the precipitate is filtered off, washed with water until it is neutral and dried at 80° C. This gives 130.8 g of perylene-3,4,9,10-tetracarboxylic dianhydride having the following extinction values:

1. temperaturemaintained at this level for two hours
2. temperatureto cool to room temperature
3. customthe precipitate which has been formed
4. filtrationis filtered off with suction
5. washwashed first with 280 g of 80% strength sulfuric acid
6. customDrying at 80° C.