Process for the manufacture of 1-hydroxy-2-pyridones

US3968118A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Gerhard Lohaus · Kelkheim, DE
• Walter Dittmar · Hofheim, DE

Key dates

• Filing date: Aug 30, 1974
• Grant date: Jul 6, 1976
• Expiry date: Aug 30, 1994

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D213/89
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

New 1-hydroxy-2-pyridones of the general formula ##SPC1## In which R.sub.1 is alkyl of 1 to 17 carbon atoms, cycloalkyl of 5 to 8 carbon atoms, cyclohexylalkyl or phenalkyl both having 1 to 3 carbon atoms in the alkylene chain or .alpha.-furyl, all of which may be substituted by halogen, and R.sub.2 to R.sub.4 are hydrogen or lower alkyl, or two adjacent substituents together form a trimethylene or tetramethylene chain, and in which R.sub.1 to R.sub.4 together contain at least 2 carbon atoms, are prepared by contacting unsaturated .delta.-keto esters or mixtures thereof with hydroxylamine and subjecting the products to cyclization.