Patent · US Expired

Process for the preparation of 1-benzoylamino-8-hydroxynaphthalene-4,6-disulphonic acid (benzoyl-K acid)

US4426333A · kind A · utility

1Cited by

0References

10Claims

0Family size

Assignee

BAYER HEALTHCARE LLC · DE

Inventors

Erich Hammerschmidt · Bensberg, DE
Horst Behre · Odenthal, DE
Bruno Kruger · Leverkusen, DE
Adolf Winkler · Leverkusen, DE

Key dates

Filing date	Apr 23, 1982
Grant date	Jan 17, 1984
Priority date	—
Expiry date	Apr 23, 2002

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC07C303/06
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

The invention relates to a process for the preparation of 1-benzoylamino-8-hydroxynaphthalene-4,6-disulphonic acid (benzoyl-K acid) by reacting 1-amino-8-hydroxynaphthalene-4,6-disulphonic acid (K acid) with benzoylating agents, according to which process mixtures of aminonaphtholdisulphonic acid isomers are used instead of pure K acid, which mixtures contain over 40% by weight of K acid, relative to the total amount of diazotizable compounds in the mixture of isomers, and in which no other single isomer has a proportion which exceeds 10% by weight of the total amount of diazotizable compounds in the mixture of isomers.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.