Bis-quinizarin compounds
AssigneeGulf Oil Corporation
InventorsClarence D. Bertino, Robert W. Hill, J. Gustav Schulz
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Abstract
Bis-quinizarin compounds are disclosed. They have the structure: ##STR1## where X is ##STR2## --CF.sub.2 --, or a bond.
Claims4
A bis-quinizarin compound having the structure:
- ##STR10## where X is ##STR11## --CF.sub.2 --, or a direct bond.
2,2'-carbonyl bis'-quinizarin having the structure:
- ##STR12##
A process for preparing 6,6'-carbonyl bis-quinizarin (CBQ) which consists essentially of heating a reaction mixture containing 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride (BTDA), p-chlorophenol, boric acid, and oleum to a temperature above 175.degree. C. for a period of time sufficient to form CBQ, washing the reaction mixture with water to remove unreacted BTDA and recovering the CBQ;
- said reaction mixture (1) containing about 1.1 to 1.9 molar portion of p-chlorophenol per molar portion of BTDA, (2) containing at least 1 molar portion of boric acid per molar portion of p-chlorophenol, and (3) containing oleum in an amount of at least 200% of the combined weight of the BTDA and p-chlorophenol.
Dependencies are inferred from the claim text.