Patent ID: 8207368

Claim:
A process for the purification by distillation of a diester of dicarbonic acid, comprising: admixing the diester of dicarbonic acid having a structure conforming to the general formula (I) where R 1 and R 2 independently of one another are straight-chain or branched C 1 -C 8 -alkyl, cycloalkyl, C 2 -C 8 -alkenyl, C 2 -C 8 -alkynyl or benzyl, each of which is optionally monosubstituted to polysubstituted, identically or differently by halogen; nitro; cyano; C 1 -C 6 -alkoxy; or dialkylamino; and/or are phenyl which is optionally monosubstituted to polysubstituted, identically or differently by halogen; nitro; cyano; alkyl; haloalkyl; alkoxy; haloalkoxy; acyl; acyloxy; alkoxycarbonyl; or carboxyl, with 0.01 to 3000 ppm of one or more phosphorus compounds, wherein the phosphorus compounds comprise at least one phosphorus-oxygen bond, thereby forming a mixture; and subsequently distilling the mixture.