The invention relates to a method for preparing caprolactam comprising recovering a mixture containing 6-aminocaproic acid, from a culture medium comprising biomass, and thereafter cyclising the 6-aminocaproic acid in the presence of superheated steam, thereby forming caprolactam, wherein the weight to weight ratio carbohydrate to 6-aminocaproic acid in said mixture is 0.03 or less.

The invention relates to a method for preparing caprolactam comprising recovering a mixture containing 6-aminocaproic acid, from a culture medium comprising biomass, and thereafter cyclising the 6-aminocaproic acid in the presence of superheated steam, thereby forming caprolactam, wherein the weight to weight ratio carbohydrate to 6-aminocaproic acid in said mixture is 0.03 or less.

The present invention relates to a process for purifying caprolactam from solutions of crude caprolactam by a direct treatment with one or more alkaline compounds of polyvalent metals, preferably bivalent and trivalent, without resorting to organic solvent extraction as used in the usual purification process.

A further subject of the present invention is a facility devoid of a unit for organic solvent extraction and designed to carry out the caprolactam purification process described herein.

The present invention relates to a process for purifying caprolactam from solutions of crude caprolactam by a direct treatment with one or more alkaline compounds of polyvalent metals, preferably bivalent and trivalent, without resorting to organic solvent extraction as used in the usual purification process.

A further subject of the present invention is a facility devoid of a unit for organic solvent extraction and designed to carry out the caprolactam purification process described herein.

The invention provides heterocyclic compounds with quaternary centers and methods of preparing compounds. Methods include the method for the preparation of a compound of Formula (II): ##STR00001##
comprising treating a compound of Formula (I): ##STR00002##
with a transition metal catalyst and under alkylation conditions as valence and stability permit.

The present disclosure discloses a method for preparing caprolactam including: (1) contacting cyclohexanone oxime with a catalyst to carry out reaction in the presence of ethanol and under the condition of gas phase Beckmann rearrangement reaction of cyclohexanone oxime; (2) separating the reaction product obtained in step (1) to produce an ethanol solution of crude caprolactam, and then separating the ethanol solution of crude caprolactam to obtain ethanol and crude caprolactam; (3) removing impurities with boiling points lower than that of caprolactam in the crude caprolactam to obtain a light component removal product; (4) mixing the light component removal product with a crystallization solvent to carry out crystallization and solid-liquid separation to obtain a crystalline crystal; (5) subjecting the crystalline crystal to a hydrogenation reaction; wherein the crystallization solvent contains 0.1-2 wt % of ethanol.

The present invention relates to a process for purifying caprolactam from solutions of cmde caprolactam by a direct treatment with one or more alkaline compounds of polyvalent metals, preferably bivalent and trivalent, without resorting to organic solvent extraction as used in the usual purification process. A further subject of the present invention is a facility devoid of a unit for organic solvent extraction and designed to carry out the caprolactam purification process described herein.

The present invention relates to a process for purifying caprolactam from solutions of cmde caprolactam by a direct treatment with one or more alkaline compounds of polyvalent metals, preferably bivalent and trivalent, without resorting to organic solvent extraction as used in the usual purification process. A further subject of the present invention is a facility devoid of a unit for organic solvent extraction and designed to carry out the caprolactam purification process described herein.

The present invention relates to a purification method for laurolactam, and more particularly, to a purification method capable of obtaining high-purity laurolactam substantially free of impurities.

The present invention provides a purification method for laurolactam from a reaction product of a laurolactam synthesis process, the production method including: (S1) obtaining a first mixed solid by separating and removing low-boiling point materials through distillation of the reaction product; (S2) removing impurities suspended in a first mixed solution obtained by dissolving the first mixed solid in a good solvent; (S3) obtaining a second mixed solid precipitated by adding a poor solvent to the first mixed solution from which the impurities are removed; and (S4) evaporating a melt obtained by heating and melting the second mixed solid to obtain laurolactam in a gas phase and performing crystallization.

The present invention relates to a purification method for laurolactam, and more particularly, to a purification method capable of obtaining high-purity laurolactam substantially free of impurities.

The present invention provides a purification method for laurolactam from a reaction product of a laurolactam synthesis process, the production method including: (S1) obtaining a first mixed solid by separating and removing low-boiling point materials through distillation of the reaction product; (S2) removing impurities suspended in a first mixed solution obtained by dissolving the first mixed solid in a good solvent; (S3) obtaining a second mixed solid precipitated by adding a poor solvent to the first mixed solution from which the impurities are removed; and (S4) evaporating a melt obtained by heating and melting the second mixed solid to obtain laurolactam in a gas phase and performing crystallization.