Patent ID: 8258340
Filing Date: 2012-09-04
Classification: C07C

Abstract:
1. A method for producing β-mercapto carboxylic acids, comprising: preparing a liquid consisting of hydrogen sulfide, a solvent, and any one of α,β-unsaturated carboxylic acids selected from an α,β-unsaturated carboxylic acid, an α,β-unsaturated carboxylic acid ester, an α,β-unsaturated amide, an α,β-unsaturated aldehyde, and an α,β-unsaturated ketone, or a liquid consisting of hydrogen sulfide, a solvent, a pH adjuster, and any one of α,β-unsaturated carboxylic acids selected from an α,β-unsaturated carboxylic acid, an α,β-unsaturated carboxylic acid ester, an α,β-unsaturated amide, an α,β-unsaturated aldehyde, and an α,β-unsaturated ketone; and then heating the liquid in a range of 70 to 200° C. to react the any one of the α,β-unsaturated carboxylic acids with the hydrogen sulfide, thereby producing any one of β-mercapto carboxylic acids which is selected from β-mercapto carboxylic acid, β-mercapto carboxylic acid ester, β-mercapto amide, β-mercapto aldehyde, and β-mercapto ketone, and corresponds to the α,β-unsaturated carboxylic acids used, wherein the liquid has a pH measured at 6° C. before the any one of the α,β-unsaturated carboxylic acids is reacted with the hydrogen sulfide in the range of 6.0 to 8.5, the pH adjuster is selected from a mineral acid, a lower carboxylic acid, a basic material containing an alkali metal or an alkaline earth metal, and an organic basic material selected from ammonia, ethylamine, propylamine, dimethylamine, diethylamine, diisopropylamine, dipropylamine, trimethylamine, triethylamine, pyridine, and morpholine, and the solvent is selected from a compound represented by the formula (1), and a mixed solvent comprising the compound represented by the formula (1) and water; wherein R