LIGAND PURIFICATION METHODS Russian patent published in 2022 - IPC C07F9/6574 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for purifying organopolyphosphite ligand, including: (a) obtaining solid organopolyphosphite ligand, which was recrystallized or ground at least once, wherein solid organopolyphosphite ligand contains more than one weight percent of impurity of oxidized phosphite and wherein organopolyphosphite ligand does not essentially contain a solvent; (b) suspending solid organopolyphosphite ligand in C₂ or higher alcohol at a temperature of at least 60°C for at least 20 minutes in order to reduce the amount of impurity of oxidized phosphite in a solid phase; and (c) removing liquid containing the dissolved impurity of oxidized phosphite from the suspension, wherein the residual content of impurity of oxidized phosphite in organopolyphosphite ligand after the stage (c) is 1% by wt. or less, and wherein the term “does not essentially contain a solvent” includes organopolyphosphite that does not contain a solvent other than the one found to be included in a solvate form, that is, the crystallization solvent.

EFFECT: purification of ligand.

10 cl, 6 ex, 2 tbl