Process for preparing di-substituted succinates

摘要

The invention relates to a process for preparing (2,3) disubstituted succinates that allows (2,3) disubstituted succinates to be obtained in good purity and with acceptable reaction yields. The (2) and (3) substitutions may be the same or different. The process comprises reacting a haloacetate with a malonic acid ester into a tricarboxylate, which is further reacted to a (2,3) disubstituted tricarboxylate, hydrolyzed, decarboxylated and optionally esterified. Esterified (2,3) disubstituted succinic esters may be used as internal donor in Ziegler-Natta type catalysts for the polymerization of olefins.

主权项

1. A process for preparing a 2,3 disubstituted succinate comprising the steps of:
a) reacting a compound [1] of formula with a compound [2] of formula to form a compound [3] of formula followed by b) reacting compound [3] with a compound of formula R2-X to form a compound [4] of formula and c) reacting compound [4] with a compound of formula R3-X to form a 2,3 disubstituted tricarboxylate compound [5] of formula followed by d) first hydrolysing compound [5] using an inorganic base and then decarboxylating the hydrolysed compound using an inorganic acid to yield a 2,3 disubstituted succinic acid compound [6] of formula wherein R and R1 may be the same or different and are selected from the group consisting of branched or linear C1-C10 hydrocarbons, and R2 and R3 may be the same or different and are selected from the group consisting of C1-C20 linear or branched alkyl, alkenyl, cycloalkyl, and alkylaryl, optionally containing heteroatoms, and X is a halogen, wherein the steps a), b) and c) are carried out in the presence of a base which may be the same or different for each of said steps.