4-Chlorophthalic anhydride → HCID 54187688, compound

HRID 1860272Notes

Reaction equation

HRID 1860272 reaction equation
[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]

Participants

3

Reactant 2

HCID 670444-Chlorophthalic anhydrideHCID 18627202HCID 18627202, compound

Product 1

HCID 54187688HCID 54187688, compound

Procedure

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.

Workup

  1. customto separate

Sources & evidence

ORD record
ord-cce0fa46299d4f1092d0d3503a195399
Source dataset
uspto-grants-2003_03
Patent number
US06528663B1

Reaction notes

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