Process for the C-alkylation of malonic esters using phase-transfer agents

US6262298A · kind A · utility

Assignee

• Huels Aktiengesellschaft · DE

Inventors

• Josef Metz · Neuss, DE
• Clemens Osterholt · Dorsten, DE

Key dates

• Filing date: Nov 24, 1998
• Grant date: Jul 17, 2001
• Expiry date: Nov 24, 2018

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C67/343
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to a process for the C-alkylation of dialkyl malonates, in which a dialkyl malonate is reacted with an alkyl halide in the presence of potassium carbonate as a hydrogen halide acceptor in an inert solvent, and a phase-transfer catalyst is not added until from 50 to 80% of the dialkyl malonate has reacted. The phase-transfer catalyst may be, for example, a tetraalkylammonium salt or a tetraalkylammonium hydroxide, a tetraalkylphosphonium salt or a tetraalkylphosphonium hydroxide or a crown ether.