A method for producing a thiol compound including a light emission process in which light is emitted to a colored thiol compound or a composition containing the thiol compound. In the light emission process, it is preferable to emit light including light with a wavelength of 250 nm to 600 nm to the composition.

A method for producing a thiol compound including a light emission process in which light is emitted to a colored thiol compound or a composition containing the thiol compound. In the light emission process, it is preferable to emit light including light with a wavelength of 250 nm to 600 nm to the composition.

A method for producing a thiol compound including a light emission process in which light is emitted to a colored thiol compound or a composition containing the thiol compound. In the light emission process, it is preferable to emit light including light with a wavelength of 250 nm to 600 nm to the composition.

The present invention relates to a new, enhanced process for the manufacture of Cysteamine Bitartrate (I) and of its key intermediate thiazolidine (II).

Furthermore, it relates to a new processes for the manufacture of crystalline anhydrous Cysteamine Bitartrate (polymorph L2) and monohydrate Cysteamine Bitartrate (polymorph L1). The crystalline anhydrous Cysteamine Bitartrate (polymorph L2) so obtained is characterized by particularly fine particle size and good appearance.

Disclosed are an S-(carboxymethyl)-cysteine pharmaceutical compound (I), and a preparation method and use thereof. Also disclosed are an S-(carboxymethyl)-D-cysteine ammonium salt monohydrate, and use thereof in preparation of medicines for preventing and treating respiratory system diseases such as chronic obstructive pulmonary diseases, in particular in preparation of expectorants. The compounds can reduce airway resistance and production of oxides in rat COPD models, increase the level of antioxidants, and alleviate damage caused by the oxides and inflammatory mediators to lungs.

Disclosed are an S-(carboxymethyl)-cysteine pharmaceutical compound (I), and a preparation method and use thereof. Also disclosed are an S-(carboxymethyl)-D-cysteine ammonium salt monohydrate, and use thereof in preparation of medicines for preventing and treating respiratory system diseases such as chronic obstructive pulmonary diseases, in particular in preparation of expectorants. The compounds can reduce airway resistance and production of oxides in rat COPD models, increase the level of antioxidants, and alleviate damage caused by the oxides and inflammatory mediators to lungs.

The present invention provides a polythiol composition containing, as the main component, a polythiol compound (a) having two or more mercapto groups, and containing 0.5% by mass or less of a nitrogen-containing compound (b) in which at least one mercapto group in the polythiol compound (a) is substituted with a group represented by formula (1).

##STR00001##

The present invention provides a polythiol composition containing, as the main component, a polythiol compound (a) having two or more mercapto groups, and containing 0.5% by mass or less of a nitrogen-containing compound (b) in which at least one mercapto group in the polythiol compound (a) is substituted with a group represented by formula (1).

##STR00001##

The present invention provides a polythiol composition containing, as the main component, a polythiol compound (a) having two or more mercapto groups, and containing 0.5% by mass or less of a nitrogen-containing compound (b) in which at least one mercapto group in the polythiol compound (a) is substituted with a group represented by formula (1).

##STR00001##

The invention relates to a process for continuously preparing methyl mercaptan by reacting a mixture comprising carbon compounds with sulfur and hydrogen, wherein the carbon disulfide and hydrogen sulfide compounds which form are subsequently converted to methyl mercaptan.