Dicyclopentadiene → 4,5,6,7-Tetrahydro-4,7-methanoisobenzofuran-1,3-dione
Reaction equation
[CH:1]1[CH2:5][CH:4]=[CH:3][CH:2]=1.C1C2C3C=CC(C2C=C1)C3.[C:16]1(=[O:22])[O:21][C:19](=[O:20])[CH:18]=[CH:17]1.B(F)(F)F.CCOCC>>[CH:1]12[CH2:5][CH:4]([CH2:3][CH2:2]1)[C:17]1[C:16]([O:21][C:19](=[O:20])[C:18]2=1)=[O:22]Participants
Conditions
- Temperature
- 100 °C
Procedure
Mixed polybasic anhydride containing a plurality of 1,2 anhydrides is obtained by distilling, at 200° C., 66.10 gms. (1 mole) of cyclopentadiene directly from dicyclopentadiene into a reactor containing 98.06 gms. (1 mole) of maleic anhydride, heated to a temperature of 55° C. When the transfer is complete, the reaction mixture is heated to 100° C. for 2 hours. The reaction mixture is then stripped of any excess cyclopentadiene at 120° C. at 1 atmosphere. The resulting Diels-Adler adduct of cyclopentadiene and maleic anhydride is the anhydride of cis-5-norbornene-2,3-dicarboxylic acid. The reaction mixture is cooled to 50° C., and 4.90 gms. (0.03 moles) of boron trifluoride etherate is added slowly with stirring. The reaction mixture exotherms to 65° C. after which it is heated to 125° C., to decompose the BF3OEt and then cooled. The reaction is quenched by mixing with 3 liters of 10% sodium bicarbonate. The mixture is then neutralized with dilute 5% hydrochloric acid. The mixed polybasic anhydride of norbornene-2,3-dicarboxylic acid anhydride is obtained as a fine tan power, Mp. 200° C., and used for foam preparation without further purification.
Workup
- customis obtained
- distillationby distilling, at 200° C.
- temperatureThe reaction mixture is cooled to 50° C.
- customexotherms to 65° C.
- temperatureis heated to 125° C.
- temperaturecooled
- customThe reaction is quenched
- additionby mixing with 3 liters of 10% sodium bicarbonate
- additionwith dilute 5% hydrochloric acid
Sources & evidence
- ORD record
- ord-9c1df3ee32c648c6ad9f27cffc07722b
- Source dataset
- uspto-grants-1987_08
- Patent number
- US04687785
Reaction notes
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