Réaction #324366

Équation de réaction

1,2,4,5-cyclohexanetetracarboxylic acid

acetic anhydride

→

1,2,4,5-cyclohexanetetracarboxylic dianhydride

Rendement 96.7%

Conditions de réaction

Traitement

1. 1
   Autreequipped with a Dimroth condenser
2. 2
   TempératureThe temperature was raised to the refluxing temperature of the solvent under a nitrogen gas atmosphere
3. 3
   Températureto reflux for 10 min
4. 4
   Autrewas decreased to room temperature
5. 5
   workup.STIRRINGunder stirring
6. 6
   Autreto precipitate crystals
7. 7
   AutreThe precipitated crystals were separated by solid-liquid separation
8. 8
   Autredried
9. 9
   Autreto obtain primary crystals
10. 10
    AutreThe mother liquor after separation
11. 11
    Concentrationwas concentrated under reduced pressure
12. 12
    Autrea rotary evaporator
13. 13
    Autreto precipitate crystals
14. 14
    AutreThe precipitated crystals were separated by solid-liquid separation
15. 15
    Autredried
16. 16
    Autreto obtain secondary crystals

Mode opératoire

Subsequently, 450 g of the obtained 1,2,4,5-cyclohexanetetracarboxylic acid and 4,000 g of acetic anhydride were charged into a 5-L glass separable flask equipped with a Dimroth condenser. The inner atmosphere of the reactor was replaced with nitrogen gas under stirring. The temperature was raised to the refluxing temperature of the solvent under a nitrogen gas atmosphere to allow the solvent to reflux for 10 min. After that, the temperature was decreased to room temperature under stirring to precipitate crystals. The precipitated crystals were separated by solid-liquid separation and dried to obtain primary crystals. The mother liquor after separation was concentrated under reduced pressure using a rotary evaporator to precipitate crystals. The precipitated crystals were separated by solid-liquid separation and dried to obtain secondary crystals. In total of the primary and secondary crystals, 375 g of 1,2,4,5-cyclohexanetetracarboxylic dianhydride was obtained (yield of the dianhydride: 96.6%).

Source