Patent · US Expired

Process for the preparation of naphthalene-1,3,5-trisulphonic acid

US4369143A · kind A · utility

1Cited by

0References

9Claims

0Family size

Assignee

BAYER HEALTHCARE LLC · DE

Inventors

Horst Behre · Odenthal, DE
Heinz U. Blank · Odenthal, DE
Wolfgang Schenk · Leverkusen, DE

Key dates

Filing date	Jul 28, 1981
Grant date	Jan 18, 1983
Priority date	—
Expiry date	Jul 28, 2001

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC07C309/00
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

A process is provided for the preparation of naphthalene-1,3-5,-trisulphonic acid from 1,5-disulphonated naphthalene, which comprises sulphonating 1,5-disulphonated naphthalene, in the form of a mixture which has been obtained by mixing naphthalene and SO.sub.3 in the presence of an inert solvent at temperatures in the range of -40.degree. to +20.degree. C., the ratio of SO.sub.3 added to naphthalene added having been in the range of 2.5 to 10 mols of SO.sub.3 per mol of naphthalene during the entire addition, at 60.degree. to 110.degree. C. in anhydrous sulphuric acid with oleum, with prior or concurrent separation of the inert solvent. The resulting product is a known intermediate for the formation of azo dyestuffs.

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