Patent ID: 6417391
Filing Date: 2002-07-09
Classification: C07C

Abstract:
A process for the preparation of a 2-methyl-1,3-dicarboxylate of formula I in which R1 and R2 independently of one another, represent a substituted or unsubstituted alkyl, aralkyl, aryl or cycloalkyl group having from 1 to about 12 carbon atoms or are a common part of a hydrocarbon chain, which comprises:(1) reacting a 1,3-dicarboxylate of formula II with hydrogen and about 1.0 to about 2.0 moles of formaldehyde per mol of said dicarboxylate of formula II, in the presence of a solvent, and a mixture of a hydrogenation catalyst and a Knoevenagel catalyst, wherein the improvement comprises (2) subjecting either the reaction mixture or a compound of formula III isolated therefrom, to thermolysis at a temperature of from about 50Â° C. to about 300Â° C. in an open system, wherein vapors which are produced during said thermolysis are removed.