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ChemicalBook CAS DataBase List Itaconic anhydride
2170-03-8

Itaconic anhydride synthesis

10synthesis methods
To a flask equipped with a 12 mm diameter ground glass adaptor tube bent for downward distillation and joined to a 100 cm condenser is added 200 gm (0.95 mole) of citric acid monohydrate. An ice-cooled flask and a cold trap are connected to the condenser. The flask containing the citric acid is heated rapidly with a wide flame of the Meker burner so that in 12-15 min the distillation at 175-190°C is complete. The distillation is stopped earlier if the vapors in the reaction flask become yellow. Superheating of the citric acid will cause rearrangement to citraconic anhydride. The water is quickly separated from the distillate and the itaconic anhydride layer dried to afford 40-50 gm (37-47%), m.p. 67-68°C. Long time contact of the water with the anhydride causes it to hydrolyze to itaconic acid, m.p. 162-165°C.
Preparation of Itaconic Anhydride
-

Yield:-

Reaction Conditions:

with acetic anhydride at 80;

Steps:

1.1; 1.2 Stage 1: Itaconic Acid Anhydride
612 g (6.0 mol) of acetic anhydride were placed in a 2-litre three-necked flask with KPG stirrer, 15-Vigreux column and column head and 780 g (6.0 mol) of solid itaconic acid was added while stirring. The mixture was then slowly heated to 80° C. until the solid was dissolved and stirred for another 30 minutes at this temperature. Subsequently, approx. 680 g acetic acid was distilled off at a vacuum between 150 and 10 mbar and a sump temperature of 80 to 82° C. The acetic acid was then removed from the sample. Approx. 690 g of sump bottom product remained, the raw yield being 680 g. The raw product was used directly in stage 2. A 5 g sample of the ester was purified by ball tube distillation and analyzed by gas chromatography and had a composition of 11 wt. % citraconic acid anhydride and 89 wt. % itaconic acid anhydride.

References:

SYMRISE AG;Chandrasekaran, Vijayanand;Panten, Johannes;Koch, Oskar;Diaz Gomez, Edison US2020/10402, 2020, A1 Location in patent:Paragraph 0317-0319

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