METHOD FOR PRODUCING A CRYSTALLINE FORM OF CALCIUM CIS-2,3-EPOXYSUCCINATE Russian patent published in 2021 - IPC C07D301/12 C07D303/48 C07C51/367 C08F20/00 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for producing a crystalline form of calcium cis-2,3-epoxysuccinate. The method includes stages a)-e). At stage a), maleic anhydride or maleic acid interacts with calcium oxide, producing acidic calcium maleate. At stage b), acidic calcium maleate is subject to epoxidation with hydrogen peroxide in the presence of an epoxidation catalyst, producing acidic calcium cis-2,3-epoxysuccinate. At stage c), the acidic calcium cis-2,3-epoxysuccinate is neutralised by adding calcium oxide. At stage d), calcium cis-2,3-epoxysuccinate is sustained for 24 to 240 hours. At stage e), the two formed crystalline forms of calcium cis-2,3-epoxyacrylate are separated, producing a crystalline form of calcium cis-2,3-epoxyacrylate, crystals whereof belong to the space group P21/n, wherein the crystal lattice parameters at 22°C are a=15.1916(2) Å, b=8.9121(1) Å, c=7.4724(1) Å, beta=103.309(1)°. The invention also relates to a method for producing the described crystalline form, wherein the crystalline form of calcium cis-2,3-epoxysuccinate with the above crystal lattice parameters is used as seeding.

EFFECT: proposed methods provides a possibility of producing a crystalline form of calcium cis-2,3-epoxysuccinate with a size of crystals from 5 to 15 mcm.

58 cl, 7 dwg, 3 tbl, 9 ex