Preparation of 4-methyl-2-pyrazolin-5-ones

US4000156A · kind A · utility

Assignee

• Agfa-Gevaert NV · BE

Inventors

• Marcel J. Monbaliu · Mortsel, BE
• Walter Puschel · Leverkusen, DE
• Raphael K. Van Poucke · Berchem, BE

Key dates

• Filing date: May 30, 1975
• Grant date: Dec 28, 1976
• Expiry date: May 30, 1995

Classification

• Technology area (CPC G): Physics
• CPC primary: G03C7/384
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A method is described for the preparation of a 1-substituted 4-methyl-2-pyrazolin-5-one by catalytic hydrogenation under pressure and simultaneous methylation by means of paraformaldehyde of the appropriate 1-substituted 2-pyrazolin-5-one in a medium of an inert organic solvent comprising ammonium acetate.