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

摘要

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.