Patent · US Expired

Process for the synthesis of 4,5-diaminopyrazole derivatives useful for dyeing hair

US5663366A · kind A · utility

300Cited by

0References

2Claims

0Family size

Assignee

Wella GmbH · DE

Inventors

Hans Neunhoeffer · Mühltal, DE
Stefan Gerstung · Reinheim, DE
Thomas Clausen · Alsbach, DE
Wolfgang Balzer · Alsbach, DE

Key dates

Filing date	May 20, 1996
Grant date	Sep 2, 1997
Priority date	—
Expiry date	May 20, 2016

Classification

Technology area (CPC A)Human Necessities
CPC primaryA61Q5/10
WIPO fieldPharmaceuticals
WIPO sectorChemistry

Abstract

The subject matter of the present invention is directed to a process for producing 4,5-diaminopyrazole derivatives of the general formula (I) ##STR1## where R.sub.1 and R.sub.2 independently designate hydrogen, a C.sub.1 - to C.sub.6 -alkyl radical or a C.sub.2 - to C.sub.4 -hydroxyalkyl radical, which can be used as dye precursors, for example for hair dyes, and to new pyrazole derivatives. When using the process according to the invention good yields of isomer-pure 4,5-diaminopyrazole derivatives of general formula (I) can be obtained.

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