Patent · US Expired

Process for the preparation of 1-aminonaphthalene-2,4,7-trisulphonic acid and 1-aminonaphthalene-7-sulphonic acid

US4836959A · kind A · utility

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4Claims

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Assignee

BAYER HEALTHCARE LLC · DE

Inventors

Willi Streicher · Krefeld, DE
Gerhard Marzolph · Cologne, DE
Horst Behre · Odenthal, DE
Heinz U. Blank · Odenthal, DE

Key dates

Filing date	Jan 26, 1988
Grant date	Jun 6, 1989
Priority date	—
Expiry date	Jan 26, 2008

Classification

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

Abstract

The invention relates to a new process for the preparation of 1-aminonaphthalene-2,4,7-trisulphonic acid and 1-aminonaphthalene-7-sulphonic acid (1,7-Cleve's acid), in which 1-aminonaphthalene or naphthionic acid is sulphonated selectively in the presence of certain additives to give 1-aminonaphthalene-2,4,7-trisulphonic acid and this is hydrolyzed to 1,7-Cleve's acid by warming in aqueous sulphuric acid.

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