There is described a method of reducing polymer tar build-up in the production of methyl methacrylate and/or methacrylic acid by the acetone cyanohydrin process. In the method a stabiliser is contacted with the amide stage reaction medium. The stabiliser includes a hydrocarbon moiety capable of donating a labile hydrogen atom to a methacrylamide derivative capable of reaction with said labile hydrogen atom under the conditions in the said medium. The method herein is especially useful for the continuous production of methyl methacrylate and/or methacrylic acid.

There is described a method of reducing polymer tar build-up in the production of methyl methacrylate and/or methacrylic acid by the acetone cyanohydrin process. In the method a stabiliser is contacted with the amide stage reaction medium. The stabiliser includes a hydrocarbon moiety capable of donating a labile hydrogen atom to a methacrylamide derivative capable of reaction with said labile hydrogen atom under the conditions in the said medium. The method herein is especially useful for the continuous production of methyl methacrylate and/or methacrylic acid.

The present specification relates to a chiral resolution method of a stereoisomer mixture, comprising a step of mixing a stereoisomer mixture of compounds, in which an amine group is bound to an asymmetric carbon atom, with a chiral auxiliary and salt-forming auxiliary compound, wherein the chiral auxiliary is an O,O-diacyltartaric acid derivative, more specifically, a 2,3-dibenzoyl-tartaric acid or O,O-di-p-toluoyl tartaric acid, the salt-forming auxiliary compound is mandelic acid or camphorsulfonic acid, and an optical isomer having a high level of optical purity can be obtained by using the method. Therefore, according to one aspect of the present invention, the method can be useful in pharmaceutical or cosmetic field when preparing an optical isomer having a high optical purity.

The present specification relates to a chiral resolution method of a stereoisomer mixture, comprising a step of mixing a stereoisomer mixture of compounds, in which an amine group is bound to an asymmetric carbon atom, with a chiral auxiliary and salt-forming auxiliary compound, wherein the chiral auxiliary is an O,O-diacyltartaric acid derivative, more specifically, a 2,3-dibenzoyl-tartaric acid or O,O-di-p-toluoyl tartaric acid, the salt-forming auxiliary compound is mandelic acid or camphorsulfonic acid, and an optical isomer having a high level of optical purity can be obtained by using the method. Therefore, according to one aspect of the present invention, the method can be useful in pharmaceutical or cosmetic field when preparing an optical isomer having a high optical purity.

The present invention relates to bis(fluorosulfonyl)imide salts, and their preparation methods. More specifically, the invention provides a new salt of bis(fluorosulfonyl)imide containing from 0.01 ppm to 10000 ppm of a halogenated alcohol. The invention further relates to a method for producing said salt of bis(fluorosulfonyl)imide, said method comprising a step of crystallizing a raw salt of bis(fluorosulfonyl)imide within a crystallization solvent comprising at least a halogenated alcohol. The use of said salt of bis(fluorosulfonyl)imide is also disclosed.

The present invention relates to bis(fluorosulfonyl)imide salts, and their preparation methods. More specifically, the invention provides a new salt of bis(fluorosulfonyl)imide containing from 0.01 ppm to 10000 ppm of a halogenated alcohol. The invention further relates to a method for producing said salt of bis(fluorosulfonyl)imide, said method comprising a step of crystallizing a raw salt of bis(fluorosulfonyl)imide within a crystallization solvent comprising at least a halogenated alcohol. The use of said salt of bis(fluorosulfonyl)imide is also disclosed.

Processes and systems for separating a mixture including at least one fluorocarboxylic acid and at least one carboxylic acid are provided herein. In some aspects, the present invention relates to processes and systems configured to provide a purified stream of fluorocarboxylic acid and a purified stream of carboxylic acid, even when the mixture includes an azeotrope, a pinch point, and/or a eutectic mixture of the fluorocarboxylic acid and carboxylic acid. Systems as described herein may include, for example, at least one distillation zone and at least one fractional crystallization zone arranged in series and configured to provide highly purified product streams having compositions heretofore unachievable by conventional means.

Processes and systems for separating a mixture including at least one fluorocarboxylic acid and at least one carboxylic acid are provided herein. In some aspects, the present invention relates to processes and systems configured to provide a purified stream of fluorocarboxylic acid and a purified stream of carboxylic acid, even when the mixture includes an azeotrope, a pinch point, and/or a eutectic mixture of the fluorocarboxylic acid and carboxylic acid. Systems as described herein may include, for example, at least one distillation zone and at least one fractional crystallization zone arranged in series and configured to provide highly purified product streams having compositions heretofore unachievable by conventional means.

The present invention relates to modified taurine and a method for preparing the same and, more particularly, to modified taurine different from conventional taurine in a distance between an intramolecular carbon (C) atom and a sulfur (S) atom adjacent thereto, and a preparation method therefor. Superior in terms of prophylactic and therapeutic effect on metabolic diseases, the modified taurine of the present invention is expected to find a wide spectrum of applications in the medical field.

Provided are a novel water-soluble diacetylene monomer, a composition for photolithography including the novel water-soluble diacetylene monomer and a conductive polymer, and a method of forming micropatterns using the composition. The water-soluble diacetylene monomer may not aggregate even when mixed with a water-soluble conductive polymer. Accordingly, a uniform composition for photolithography can be prepared by mixing a water-soluble conductive polymer with the diacetylene monomer, and micropatterns can be formed using the composition. More particularly, when the composition is formed into a thin film and then is irradiated with light, only light-irradiated portions of the diacetylene monomer are selectively crosslinked due to photopolymerization, thereby resulting in insoluble negative-type micropatterns.