Disclosed is a limonene-sulfur polysulfide and methods for preparing the same. The polysulfide prepared according to these methods is flexible, moldable and otherwise capable of being formed in any manner consistent with a thermoplastic polymer. The limonene-sulfur polysulfide has been demonstrated to sequester inorganic palladium and inorganic mercury dissolved in water.

Disclosed is a limonene-sulfur polysulfide and methods for preparing the same. The polysulfide prepared according to these methods is flexible, moldable and otherwise capable of being formed in any manner consistent with a thermoplastic polymer. The limonene-sulfur polysulfide has been demonstrated to sequester inorganic palladium and inorganic mercury dissolved in water.

The present invention includes methods for making and isolating N-acetylcysteine amide, intermediates and derivatives thereof comprising: contacting cystine with an alcohol and a chlorinating reagent to form an organic solution containing L-cystine dimethylester dihydrochloride; combining dried or undried L-cystine dimethylester dihydrochloride with a triethylamine, an acetic anhydride, and an acetonitrile to form a di-N-acetylcystine dimethylester; mixing dried di-N-acetylcystine dimethylester with ammonium hydroxide to form a di-N-acetylcystine amide; and separating dried di-N-acetylcystine dimethylester into N-acetylcysteine amide with dithiothreitol, triethylamine and an alcohol.

The present invention includes methods for making and isolating N-acetylcysteine amide, intermediates and derivatives thereof comprising: contacting cystine with an alcohol and a chlorinating reagent to form an organic solution containing L-cystine dimethylester dihydrochloride; combining dried or undried L-cystine dimethylester dihydrochloride with a triethylamine, an acetic anhydride, and an acetonitrile to form a di-N-acetylcystine dimethylester; mixing dried di-N-acetylcystine dimethylester with ammonium hydroxide to form a di-N-acetylcystine amide; and separating dried di-N-acetylcystine dimethylester into N-acetylcysteine amide with dithiothreitol, triethylamine and an alcohol.

The present invention includes methods for making and isolating N-acetylcysteine amide, intermediates and derivatives thereof comprising: contacting cystine with an alcohol and a chlorinating reagent to form an organic solution containing L-cystine dimethylester dihydrochloride; combining dried or undried L-cystine dimethylester dihydrochloride with a triethylamine, an acetic anhydride, and an acetonitrile to form a di-N-acetylcystine dimethylester; mixing dried di-N-acetylcystine dimethylester with ammonium hydroxide to form a di-N-acetylcystine amide; and separating dried di-N-acetylcystine dimethylester into N-acetylcysteine amide with dithiothreitol, triethylamine and an alcohol.

For efficiently producing a dialkyl polysulfide which is able to be favorably used as an extreme-pressure additive which does not easily corrode the metal surface, and an extreme-pressure additive and lubricating fluid composition including the dialkyl polysulfide, provided is a method for producing dialkyl polysulfide including a first step of reacting an olefin compound (a) represented by General Formula (1): R.sup.1R.sup.2CCHR.sup.3 (where R.sup.1 and R.sup.2 each are an alkyl group, R.sup.3 is a hydrogen atom or an alkyl group, and the total number of carbon atoms of R.sup.1, R.sup.2 and R.sup.3 is 2 to 20) with sulfur in the presence of a hydrogen sulfide to thereby obtain crude dialkyl polysulfide (A), and a second step of reacting the crude dialkyl polysulfide (A) and a sulfide of an alkali metal in a solvent including an alcohol to thereby reduce the number of sulfur atoms in the crude dialkyl polysulfide (A).

For efficiently producing a dialkyl polysulfide which is able to be favorably used as an extreme-pressure additive which does not easily corrode the metal surface, and an extreme-pressure additive and lubricating fluid composition including the dialkyl polysulfide, provided is a method for producing dialkyl polysulfide including a first step of reacting an olefin compound (a) represented by General Formula (1): R.sup.1R.sup.2CCHR.sup.3 (where R.sup.1 and R.sup.2 each are an alkyl group, R.sup.3 is a hydrogen atom or an alkyl group, and the total number of carbon atoms of R.sup.1, R.sup.2 and R.sup.3 is 2 to 20) with sulfur in the presence of a hydrogen sulfide to thereby obtain crude dialkyl polysulfide (A), and a second step of reacting the crude dialkyl polysulfide (A) and a sulfide of an alkali metal in a solvent including an alcohol to thereby reduce the number of sulfur atoms in the crude dialkyl polysulfide (A).

For efficiently producing a dialkyl polysulfide which is able to be favorably used as an extreme-pressure additive which does not easily corrode the metal surface, and an extreme-pressure additive and lubricating fluid composition including the dialkyl polysulfide, provided is a method for producing dialkyl polysulfide including a first step of reacting an olefin compound (a) represented by General Formula (1): R.sup.1R.sup.2CCHR.sup.3 (where R.sup.1 and R.sup.2 each are an alkyl group, R.sup.3 is a hydrogen atom or an alkyl group, and the total number of carbon atoms of R.sup.1, R.sup.2 and R.sup.3 is 2 to 20) with sulfur in the presence of a hydrogen sulfide to thereby obtain crude dialkyl polysulfide (A), and a second step of reacting the crude dialkyl polysulfide (A) and a sulfide of an alkali metal in a solvent including an alcohol to thereby reduce the number of sulfur atoms in the crude dialkyl polysulfide (A).

The present invention relates to an industrial process for the preparation of (5S,10S)-10-benzyl-16-methyl-11,14,18-trioxo-15,17,19-trioxa-2,7,8-trithia-12-azahenicosan-5-aminium (E)-3-carboxyacrylate salt of following formula (I): wherein X is fumarate. This process comprises the following successive key steps: a kinetic resolution, formation of disulfide compound, peptide coupling, and anion exchange reaction to obtain the desired product of formula (I). ##STR00001##

The present invention relates to an industrial process for the preparation of (5S,10S)-10-benzyl-16-methyl-11,14,18-trioxo-15,17,19-trioxa-2,7,8-trithia-12-azahenicosan-5-aminium (E)-3-carboxyacrylate salt of following formula (I): wherein X is fumarate. This process comprises the following successive key steps: a kinetic resolution, formation of disulfide compound, peptide coupling, and anion exchange reaction to obtain the desired product of formula (I). ##STR00001##