Provided are a method of preparing laurolactam including: a) synthesizing laurolactam by Bechmann rearrangement of cyclododecanone oxime under a catalyst system, b) mixing the laurolactam synthesized in a) with a good solvent and removing the catalyst system, and c) mixing the laurolactam from which the catalyst system has been removed in b) with a poor solvent and performing recrystallization, a synthesis device thereof, a laurolactam composition prepared therefrom, and a method of preparing polylaurolactam using the laurolactam composition.

Provided are a method of preparing laurolactam including: a) synthesizing laurolactam by Bechmann rearrangement of cyclododecanone oxime under a catalyst system, b) mixing the laurolactam synthesized in a) with a good solvent and removing the catalyst system, and c) mixing the laurolactam from which the catalyst system has been removed in b) with a poor solvent and performing recrystallization, a synthesis device thereof, a laurolactam composition prepared therefrom, and a method of preparing polylaurolactam using the laurolactam composition.

The invention provides a process and a plant for the production of ε-caprolactam and crystalline ammonium sulfate in an industrial-scale plant, wherein the plant comprises a Beckmann rearrangement reaction section, an ammonium sulfate crystallization section, and one or more heat exchangers configured to transfer heat from the Beckmann rearrangement reaction section to the ammonium sulfate crystallization section and wherein the process comprises the steps of: a) feeding (i) cyclohexanone oxime and (ii) oleum and/or sulfuric acid to the Beckmann rearrangement reaction section b) reacting components (i) and (ii) in the Beckmann rearrangement reaction section to form a reaction mixture comprising ε-caprolactam, whereby heat of reaction is generated; c) discharging the reaction mixture comprising ε-caprolactam from the Beckmann rearrangement reaction section; d) removing partially or fully the heat of reaction generated in the Beckmann rearrangement reaction section by one or more heat exchangers configured to transfer heat from the Beckmann rearrangement reaction section; e) feeding an aqueous liquid comprising ammonium sulfate to the ammonium sulfate crystallization section; f) introducing heat into the ammonium sulfate crystallization section comprising the aqueous ammonium-sulfate-comprising liquid by one or more heat exchangers configured to transfer heat into the ammonium sulfate crystallization section; g) forming ammonium sulfate crystals by evaporative crystallization in the ammonium sulfate crystallization section;
characterized in that h) the heat of reaction removed from the Beckmann rearrangement reaction section in step d) is at least partially or fully transferred to the ammonium sulfate crystallization section in step f).

The invention provides a process and a plant for the production of ε-caprolactam and crystalline ammonium sulfate in an industrial-scale plant, wherein the plant comprises a Beckmann rearrangement reaction section, an ammonium sulfate crystallization section, and one or more heat exchangers configured to transfer heat from the Beckmann rearrangement reaction section to the ammonium sulfate crystallization section and wherein the process comprises the steps of: a) feeding (i) cyclohexanone oxime and (ii) oleum and/or sulfuric acid to the Beckmann rearrangement reaction section b) reacting components (i) and (ii) in the Beckmann rearrangement reaction section to form a reaction mixture comprising ε-caprolactam, whereby heat of reaction is generated; c) discharging the reaction mixture comprising ε-caprolactam from the Beckmann rearrangement reaction section; d) removing partially or fully the heat of reaction generated in the Beckmann rearrangement reaction section by one or more heat exchangers configured to transfer heat from the Beckmann rearrangement reaction section; e) feeding an aqueous liquid comprising ammonium sulfate to the ammonium sulfate crystallization section; f) introducing heat into the ammonium sulfate crystallization section comprising the aqueous ammonium-sulfate-comprising liquid by one or more heat exchangers configured to transfer heat into the ammonium sulfate crystallization section; g) forming ammonium sulfate crystals by evaporative crystallization in the ammonium sulfate crystallization section;
characterized in that h) the heat of reaction removed from the Beckmann rearrangement reaction section in step d) is at least partially or fully transferred to the ammonium sulfate crystallization section in step f).

The present invention relates to a laurolactam preparation method and synthesis apparatus, and epoxidation and a rearrangement reaction are performed in the conversion of cyclododecene into cyclododecanone so that the preparation method can synthesize laurolactam having a higher purity with a higher selectivity and in a higher yield than a conventional preparation method.

The present invention relates to a laurolactam preparation method and synthesis apparatus, and epoxidation and a rearrangement reaction are performed in the conversion of cyclododecene into cyclododecanone so that the preparation method can synthesize laurolactam having a higher purity with a higher selectivity and in a higher yield than a conventional preparation method.

The present invention relates to nitric oxide releasing prodrugs of known drugs or therapeutic agents wherein the drug or therapeutic agents contain at least one carboxylic acid group. The invention also relates to processes for the preparation of these nitric oxide releasing prodrugs, to pharmaceutical compositions containing them and to methods of using these produgs.

Provided are a photoirradiation device equipped with: a first optically transparent container for covering a light-emitting body provided with light-emitting diodes; a liquid phase section provided on the outside thereof and formed from a liquid having a refractive index closer to that of the first optically transparent container than that of a gas forming a gas phase section inside the first optically transparent container; and a second optically transparent container for covering the liquid phase section, a photoreaction method using the photoirradiation device, and a method for producing lactam by using the photoreaction method. The reflection of light between a target liquid and a light-emitting diode light source is suppressed, and a desired photoirradiation can be achieved with a high optical transparency.

Provided are a photoirradiation device equipped with: a first optically transparent container for covering a light-emitting body provided with light-emitting diodes; a liquid phase section provided on the outside thereof and formed from a liquid having a refractive index closer to that of the first optically transparent container than that of a gas forming a gas phase section inside the first optically transparent container; and a second optically transparent container for covering the liquid phase section, a photoreaction method using the photoirradiation device, and a method for producing lactam by using the photoreaction method. The reflection of light between a target liquid and a light-emitting diode light source is suppressed, and a desired photoirradiation can be achieved with a high optical transparency.

Provided is a photochemical reaction device wherein two partitions formed from an optically transparent material are arranged apart from each other between a light source and a reaction liquid, and an optically transparent fluid introduction/discharge means for introducing an optically transparent fluid between the partitions and discharging the fluid and a state change detection means for detecting a change in the state of the optically transparent fluid at the discharge side of the optically transparent fluid introduction/discharge means are provided. Also provided are a photochemical reaction method that uses the photochemical reaction device and a lactam production method that uses the photochemical reaction method. The present invention prevents decreases in the performance of the light source even when the optically transparent material in the photochemical reaction device is damaged, and makes it possible to reliably prevent ignition even if the reaction liquid is a flammable liquid.