Preparation of alkoxy(iso)violanthrenediones
AssigneeBASF SE
InventorsReinhard Helwig, Helmut Hoch
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Abstract
A process for the preparation of bisalkoxy(iso)violanthrenediones involves alkylating the corresponding bishydroxyl compounds in an organic reaction medium with methyl benzoate as the reaction medium. The ester can easily be regenerated and is stable under the reaction conditions.
Claims16
A process for the preparation of a bisalkoxyviolanthrenediene or bisalkoxyisoviolanthrenedione of the formula ##STR2## where R is C.sub.1 -C.sub.4 -alkyl, which comprises alkylating the corresponding bishydroxyl compound (R=H) in methyl benzoate as the reaction medium in the presence of an alkali metal salt of a weak acid and a tertiary aliphatic or tertiary aromatic amine, or a mixture of tertiary aliphatic and tertiary aromatic amines, at from 100.degree. to 200.degree. C.
Dependencies are inferred from the claim text.