5-Norbornene-2,3-dicarboxylic acid

Chemical Properties

white powder

Uses

5-Norbornene-2,3-dicarboxylic acid is used to prepare cyclic olefin copolymers and is also an important raw material for the synthesis of the antidepressant drug lurasidone.

Health Hazard

5-Norbornene-2,3-dicarboxylic acid Causes skin irritation and serious eye irritation, it may cause respiratory irritation, it is harmful if swallowed, in contact with skin or if inhaled.

Synthesis

The general procedure for the synthesis of 5-norbornene-2,3-dicarboxylic acid from nadic anhydride was as follows: in a 125 mL three-necked flask, 8 g of maleic anhydride and 26 mL of ethyl acetate were added, and the mixture was heated through a hot water bath until all solids were completely dissolved. Subsequently, 26 mL of petroleum ether (boiling range 60-90 °C) was added and the mixture was cooled to room temperature. Next, the mixture was further cooled using an ice water bath and 6 mL of freshly distilled cyclopentadiene was slowly added. The reaction mixture was placed in an ice-water bath with continuous stirring until a white solid precipitate precipitated, forming white needle-like crystals. The product was collected by diafiltration and washed with 15 mL of a mixture of ethyl acetate and petroleum ether. 12 g of Bicyclo[2.2.1]-2-heptene-5,6-dicarboxylic anhydride was finally obtained in about 84% yield with a melting point of 163.5-165.5 °C. 12 g of the above product was dissolved in 35 mL of 20% sodium hydroxide solution and heated to reflux for 1.5 h. The color of the solution changed from colorless to yellow. After continuing to reflux for 2 hours, the heating was stopped and cooled to room temperature. The reaction solution was transferred to a 100 mL beaker and filtered while hot. After the filtrate was cooled, it was acidified with concentrated hydrochloric acid to pH 2-3, and white needle-like crystals were precipitated. The crystals were collected by filtration and dried to give 10 g of 5-norbornene-2,3-dicarboxylic acid in 84% yield with a melting point of 167-168 °C.

References

[1] Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1989, vol. 38, # 4.2, p. 789 - 792
[2] Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1989, # 4, p. 878 - 882
[3] Patent: CN106905377, 2017, A. Location in patent: Paragraph 0038; 0039; 0040