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US 4,781,862 AGranted
Process for the preparation of anthraquinone
AssigneeMontvale Process Company, Inc.
InventorAlan E. Goliaszewski
Life of this patent
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Abstract
Anthraquinone is produced by reacting phthalic anhydride in the vapor phase over a catalyst which may be an oxide of the Group 4b metals zirconium, hafnium, and titanium, the Group 5b metals niobium, tantalum, and vanadium, or the rare earths cerium and thorium such oxides, preferably being treated with sulfuric acid and calcined. Substituted anthraquinones may be produced by employing the corresponding substituted phthalic anhydrides.
Claims13
A process for the production of anthraquinone comprising:
- reacting two molecules of phthalic anhydride in the vapor phase, in the substantial absence of benzene, to form anthraquinone and carbon dioxide in the presence of a catalyst consisting of oxides of at least one member of the group of Group 4b metals zirconium, hafnium, and titanium, the Group 5b metals niobium, tantalum, and vanadium, or the rare earths cerium and thorium at a temperature in the range of 350.degree.-550.degree. C. and a pressure in the range of 0.01-200 bar, said temperature and pressure being selected to maintain the phthalic anhydride in the vapor phase.
A process for the production of lower alkyl substituted anthraquinones comprising:
- (a) reacting two molecules of the corresponding lower alkyl substituted phthalic anhydride to form the desired substituted anthraquinone and carbon dioxide in the presence of a catalyst consisting of the oxides of at least one member of the group of Group 4b metals zirconium, hafnum, and titanium, the Group 5b metals niobium, tantalum, and vanadium, or the rare earths cerium and thorium, in the substantial absence of benzene, at a temperature in the range of 350.degree.-550.degree. C. and a pressure in the range of 0.01-200 bar, said temperature and pressure being selected to maintain the lower alkyl phthalic anhydride in the vapor phase;
- (b) separating the lower alkyl substituted anthraquinone produced in step (a).
Dependencies are inferred from the claim text.