Provided are processes for the preparation of (S)-tert-butyl 4,5-diamino-5-oxopentanoate, or a salt, solvate, hydrate, enantiomer, mixture of enantiomers, or isotopologue thereof. Also provided are solid forms of various intermediates and products obtained from the processes.

Provided are processes for the preparation of (S)-tert-butyl 4,5-diamino-5-oxopentanoate, or a salt, solvate, hydrate, enantiomer, mixture of enantiomers, or isotopologue thereof. Also provided are solid forms of various intermediates and products obtained from the processes.

Provided are processes for the preparation of (S)-tert-butyl 4,5-diamino-5-oxopentanoate, or a salt, solvate, hydrate, enantiomer, mixture of enantiomers, or isotopologue thereof. Also provided are solid forms of various intermediates and products obtained from the processes.

The present invention relates to a process for obtaining amidated fatty acids or derivatives thereof good in color even after longer storage with low concentrations of undesired by-products. The present invention also relates to use of amidated fatty acids or derivatives thereof obtained by the process in the cosmetic applications. Further, the present invention also relates to use of amidated fatty acids or derivatives thereof obtained by the process in the industrial applications.

The present invention relates to a process for obtaining amidated fatty acids or derivatives thereof good in color even after longer storage with low concentrations of undesired by-products. The present invention also relates to use of amidated fatty acids or derivatives thereof obtained by the process in the cosmetic applications. Further, the present invention also relates to use of amidated fatty acids or derivatives thereof obtained by the process in the industrial applications.

A method for producing N-vinylacetamide includes a feeding step of feeding a raw material containing N-(1-methoxyethyl)acetamide (MEA) to an evaporator, an evaporation step of evaporating, by the evaporator, the raw material, to form a vaporized raw material, a superheating step of feeding the vaporized raw material to a superheater, and superheating the vaporized raw material such that a superheating temperature of the vaporized raw material is equal to or more than a temperature higher by 5° C. than a boiling point of the N-(1-methoxyethyl)acetamide (MEA) under an inner pressure of the superheater and equal to or less than 200° C., and a thermal decomposition step of feeding the superheated vaporized raw material to a thermal decomposition reactor, to thermally decompose the superheated vaporized raw material, and a content of the N-(1-methoxyethyl)acetamide in the raw material is from 80 to 100 mass %.

A method for producing N-vinylacetamide includes a feeding step of feeding a raw material containing N-(1-methoxyethyl)acetamide (MEA) to an evaporator, an evaporation step of evaporating, by the evaporator, the raw material, to form a vaporized raw material, a superheating step of feeding the vaporized raw material to a superheater, and superheating the vaporized raw material such that a superheating temperature of the vaporized raw material is equal to or more than a temperature higher by 5° C. than a boiling point of the N-(1-methoxyethyl)acetamide (MEA) under an inner pressure of the superheater and equal to or less than 200° C., and a thermal decomposition step of feeding the superheated vaporized raw material to a thermal decomposition reactor, to thermally decompose the superheated vaporized raw material, and a content of the N-(1-methoxyethyl)acetamide in the raw material is from 80 to 100 mass %.

A method for producing N-vinylacetamide includes a feeding step of feeding a raw material containing N-(1-methoxyethyl)acetamide (MEA) to an evaporator, an evaporation step of evaporating, by the evaporator, the raw material, to form a vaporized raw material, a superheating step of feeding the vaporized raw material to a superheater, and superheating the vaporized raw material such that a superheating temperature of the vaporized raw material is equal to or more than a temperature higher by 5° C. than a boiling point of the N-(1-methoxyethyl)acetamide (MEA) under an inner pressure of the superheater and equal to or less than 200° C., and a thermal decomposition step of feeding the superheated vaporized raw material to a thermal decomposition reactor, to thermally decompose the superheated vaporized raw material, and a content of the N-(1-methoxyethyl)acetamide in the raw material is from 80 to 100 mass %.

The present invention provides a method for chiral resolution of Trolox. The present disclosure relates to a method for producing a solid salt of a compound of formula I, wherein an amide-based solvent is added to a sample, which contains a compound of formula I, while being assumed to contain a compound of formula II, in the presence of an optical resolution agent:

##STR00001## Formula I: (R)-6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid (hereinafter referred to R Trolox)

##STR00002## Formula II: (S)-6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid (hereinafter referred to S Trolox).

The present invention provides a method for chiral resolution of Trolox. The present disclosure relates to a method for producing a solid salt of a compound of formula I, wherein an amide-based solvent is added to a sample, which contains a compound of formula I, while being assumed to contain a compound of formula II, in the presence of an optical resolution agent:

##STR00001## Formula I: (R)-6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid (hereinafter referred to R Trolox)

##STR00002## Formula II: (S)-6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid (hereinafter referred to S Trolox).