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US 4,396,768 AGranted
Process for the preparation of anionic quinophthalone dyestuffs
AssigneeBayer Aktiengesellschaft
InventorAlfred Brack
Life of this patent
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Abstract
Quinophthalone dyestuffs containing sulpho groups are obtained in a particularly advantageous manner by reacting a corresponding quinaldine derivative with a phthalic anhydride at 160.degree.-240.degree. C. in quinoline.
Claims2
Process for the preparation of anionic quinophthalone dyestuffs of the formula ##STR7## wherein R represents hydrogen or methyl and
- R.sup.1 represents hydrogen or the carboxyl or sulphonic acid group, characterised in that a quinaldine derivative of the formula ##STR8## wherein R denotes hydrogen or methyl,
- is subjected to a condensation reaction with phthalic anhydride, trimellitic anhydride, 4-sulpho-phthalic anhydride or 4-sulpho-phthalic acid in quinoline at 160.degree.-240.degree. C.
Dependencies are inferred from the claim text.