4-Chlorophthalic anhydride → HCID 54187688, Verbindung
Reaktionsgleichung
[Cl:1][C:2]1[CH:3]=[C:4]2[C:9](=[O:10])[O:8][C:6](=[O:7])[C:5]2=[CH:11][CH:12]=1.[Pb].ClC1C=C2C(=O)OC(=O)C2=CC=1>>[Cl:1][CH:2]1[CH:12]=[CH:11][CH:5]2[C:6]([O:8][C:9](=[O:10])[CH:4]2[CH2:3]1)=[O:7]Komponenten
3
Versuchsvorschrift
4-Chlorophthalic anhydride is an expensive starting material which presently must be custom synthesized. Current routes for the synthesis of 4-chlorophthalic anhydride lead to mixtures of isomers, which are difficult to separate, or are prohibitively costly. For example, the Diels-Alder condensation of maleic anhydride with 2-chloro-1,3-butadiene to yield 4-chlorotetrahydrophthalic anhydride, followed by aromatization in the presence bromine requires the subsequent recovery of HBr. Attempted thermal aromatization of 4-chloro-tetrahydrophthalic anhydride results in low yields of 4-chlorophthalic anhydride and tar formation. This and other routes are described in U.S. Pat. Nos. 5,059,697; 5,003,088; 5,322,954; 4,978,760 and 5,233,054.
Aufarbeitung
- customto separate