# US 4,396,768 A · Process for the preparation of anionic quinophthalone dyestuffs

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- Number: US 4,396,768 A
- Document ID: US4396768A
- Status: Granted
- Kind: A
- Application number: 06/269,238
- Filed: 1981-06-01
- Granted: 1983-08-02
- Earliest claimed: 1980-06-19
- Assignees: Bayer Aktiengesellschaft
- Inventors: Alfred Brack
- Web page: https://patentgrep.com/patent/US4396768A

## CPC

- C09B 67/0073: {Preparations of acid or reactive dyes in liquid form}
- C09B 25/00: Quinophthalones
- C09B: ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES {, e.g. PIGMENTS}; MORDANTS; LAKES (fermentation or enzyme using processes to synthesise a desired chemical compound C12P)

## 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.

## Claims

### Claim 1

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.

### Claim 2 (depends on 1)

Process for the preparation of anionic quinophthalone dyestuffs of claim 1 wherein the condensation reaction is carried out at 180.degree.-220.degree. C.