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US 4,379,092 AGranted
Process for the preparation of anthraquinone and its substituted derivatives
AssigneeP C U K Produits Chimiques Ugine Kuhlmann
InventorMichel Devic
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Abstract
A process for the preparation of anthraquinone compounds by condensation of phthalic anhydride with a benzene derivative wherein a mixture of hydrofluoric acid and boron trifluoride is utilized as catalyst.
Claims7
Process for the preparation of anthraquinone compounds of the general formula:
- ##STR6## in which R.sub.1, R.sub.2, R.sub.3, R.sub.4 represent hydrogen, halogen or a linear or branched alkyl containing 1 to 5 carbon atoms which comprises reacting a phthalic anhydride or substituted phthalic anhydride of the formula:
- ##STR7## with a benzene compound of the formula:
- ##STR8## wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4 have the same definition as above, in the presence of a catalyst mixture of hydrofluoric acid and boron trifluoride, and converting the thus obtained o-benzoyl benzoic acid of the formula:
- ##STR9## in which R.sub.1, R.sub.2, R.sub.3, and R.sub.4 have the same definition as above, into the compound of formula (I) by cyclization.
1 more element
Dependencies are inferred from the claim text.