反应详情

Into a 5-L separable glass flask equipped with a Dimroth condenser, were charged 450 g of 1,2,4,5-cyclohexanetetracarboxylic acid thus obtained and 4000 g of acetic anhydride, and the inner atmosphere was replaced with nitrogen gas while stirring the contents. The contents were heated to a refluxing temperature of the solvent in nitrogen gas atmosphere to reflux the solvent for 10 min, and thereafter, cooled to room temperature under stirring to precipitate crystals. The crystals were subjected to solid-liquid separation and dried to obtain primary crystals. The mother liquor was concentrated under reduced pressure using a rotary evaporator to precipitate crystals. The precipitated crystals were subjected to solid-liquid separation and dried to obtain secondary crystals. Thus, 375 g of 1,2,4,5-cyclohexanetetracarboxylic dianhydride in total of the primary and secondary crystals was obtained (anhydration yield: 96.6%).

1. customInto a 5-L separable glass flask equipped with a Dimroth condenser
2. customthus obtained
3. temperatureThe contents were heated to a refluxing temperature of the solvent in nitrogen gas atmosphere
4. temperatureto reflux the solvent for 10 min
5. stirringunder stirring
6. customto precipitate crystals
7. customThe crystals were subjected to solid-liquid separation
8. customdried
9. customto obtain primary crystals
10. concentrationThe mother liquor was concentrated under reduced pressure
11. customa rotary evaporator
12. customto precipitate crystals
13. customThe precipitated crystals were subjected to solid-liquid separation
14. customdried
15. customto obtain secondary crystals