Patent · US Expired

Process for preparing substituted 4,4'-diaminostilbene-2,2'-disulphonic acid salts

US6121444A · kind A · utility

3Cited by

7References

10Claims

0Family size

Assignee

BAYER HEALTHCARE LLC · DE

Inventors

Ulrich Feldhues · Bensberg, DE
Udo Eckstein · Cologne, DE
Uwe Vogt · Monheim, DE
Rolf Brockmann · Bensberg, DE

Key dates

Filing date	Jan 24, 1999
Grant date	Sep 19, 2000
Priority date	—
Expiry date	Jan 24, 2019

Classification

Technology area (CPC D)Textiles; Paper
CPC primaryD06L4/621
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

In the preparation of substituted 4,4'-diaminostilbene-2,2'-disulfonic acid salts a clear increase in the reaction rate may be achieved by carrying out the reaction of the tetrachlorine derivative (III) with the aniline (IV) in the presence of the amine (VI) as acid-absorber.

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