Method for the production of 1-substituted 5-hydroxypyrazoles

US6329530A · kind A · utility

Assignee

• BASF SE

Inventors

• Volker Maywald · Ludwigshafen, DE
• Adrian Steinmetz · Mannheim, DE
• Michael Rack · Eppelheim, DE
• Norbert Gotz · Worms, DE
• Roland Götz · Ludwigshafen, DE
• Jochem Henkelmann · Mannheim, DE
• Heike Becker · Mannheim, DE
• Juan Jose Aiscar Bayeto · Mannheim, DE

Key dates

• Filing date: May 3, 2001
• Grant date: Dec 11, 2001
• Expiry date: May 3, 2021

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D231/20
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to a method for the production of 1-substituted 5-hydroxypyrazoles of formula (I) wherein R.sup.1 is C.sub.1 -C.sub.6 -alkyl, C.sub.2 -C.sub.6 -alkenyl, C.sub.2 -C.sub.6 -alkinyl, C.sub.3 -C.sub.6 -cycloalkyl or C.sub.1 -C.sub.4 -alkoxy, whereby these groups can be substituted by halogen, C.sub.1 -C.sub.4 -alkoxy, phenoxy, C.sub.1 -C.sub.6 -alkoxycarbonyl, C.sub.1 -C.sub.6 -alkylthiocarbonyl or a cyclic ring system with 3-14 ring atoms, by reacting a) an alkylvinylether of general formula (III) wherein R.sup.2 is C.sub.1 -C.sub.6 -alkyl or C.sub.3 -C.sub.6 -cycloalkyl, with phosgene (IVa), "diphosgene" (IVb) or "triphosgene" (IVc) to form acid chlorides of formula (V), b) transforming said acid chlorides by eliminating hydrogen chloride into the corresponding 3-alkoxyacrylic acid chloride of formula (VI) and c) reacting said acid chloride with hydrazines of formula (VII) wherein R.sup.1 has the above cited meaning, to form 5-hydroxypyrazoles of formula (I). ##STR1##