Telescoping synthesis of 5-amino-4-nitroso-1-alkyl-1H-pyrazole salt

US8785656B2 · kind B2 · utility

Assignee

• The Procter & Gamble Company · US

Inventors

• Wolfram Geibel · Nettetal, DE
• Ingo Weber · Basel, CH
• Armin Osan · Darmstadt, DE
• Markus Speckbacher · Aschaffenburg, DE

Key dates

• Filing date: Feb 15, 2013
• Grant date: Jul 22, 2014
• Expiry date: Feb 15, 2033

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D231/38
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A telescoping synthesis of 5-amino-4-nitroso-1-alkyl-1H-pyrazole salt derivatives of formula (I), the compound (I) itself, and its use as an intermediate in the fabrication of 1-alkyl-4,5-diaminopyrazole salts of general formula (IX). The compounds of formula (IX) can be used as precursor dyes in oxidative hair dye compositions.R is a mono- or poly-substituted or unsubstituted, straight or branched, saturated or mono- or poly-unsaturated, alkyl group. HZ and HZ′ are organic or mineral acids.