42 results about "Potassium thioacetate" patented technology

The invention discloses a method for preparing a D-biotin thiolactone intermediate, which comprises the following steps: a) adding the lactone intermediate and potassium thioacetate to a reaction vessel at a mass ratio of 2:1 to 2.4:1 , heating until the reaction system is in a completely molten state, and then insulated and stirred for 1 to 5 hours; b) cooling down to 50 to 80°C, and then adding 2 to 10 milliliters of water to the reaction system according to 1 gram of lactone intermediate; c) ) lowering the temperature of the reaction system to 0-10°C while stirring, and then maintaining the temperature and continuing to stir for 1-5 hours; d) filtering, and the collected solid is the D-biotinthiolactone intermediate. The invention realizes the participation of no solvent in the reaction, not only has no problems of solvent environmental protection and recovery, but also has low preparation cost and very simple operation process, especially, the high-purity target object with HPLC purity ≥ 99.5% can be obtained only by filtering and washing with water , and the mass yield ≥ 95%.

The invention relates to a preparation method for selectively synthesizing cis-4-n-amyl cyclohexylmereaptan, which belongs to the field of organic synthesis. The method comprises the following steps: 4-pentylcyclohexanone and sodium borohydride are added into a tetrahydrofuran water mixed solvent, the materials are subjected to a reduction reaction to obtain the 4-amylcyclohexanol; the 4-amylcyclohexanol and methylsulfonyl chloride are subjected to a methyl sulfonylation reaction in a dichloroethanes solvent, the 4-n-amyl cyclohexyl sulfonate with content of more than 98% can be obtained through crystallization; the 4-n-amyl cyclohexyl sulfonate and potassium thioacetate are subjected to a sulfur acetylation reaction in a N,N-dimethyl formamide solvent to obtain the thiolacetic acid-4-n-amyl cyclohexyl ring; the material is subjectd to a low-temperature saponification reaction in a methanol hydrosolvent to obtain the cis-4-n-amyl cyclohexylmereaptan, and the cis products selectivity is greater than 99%. The method has the advantages of short reaction time, simple operation, and high cis products selectivity.

The invention discloses a method for synthesis of 1-(4, 5-dihydro-2-thiazolinyl)-3-mercaptoazetidine hydrochloride. With 2-methylthio-2-thiazoline (I) as the raw material, the method of the invention comprises the steps of: in the presence of alkali, reacting 2-methylthio-2-thiazoline (I) with 3-hydroxyazetidine hydrochloride so as to obtain 1-(4, 5-dihydro-2-thiazolinyl)-3-hydroxyazetidine (II), and reacting (II) with methyl sulfonylchloride in the presence of alkali so as to obtain 1-(4, 5-dihydro-2-thiazolinyl)-3-methane sulfonate group azetidine (III), subjecting (III) to a reaction with potassium thioacetate so as to obtain 1-(4, 5-dihydro-2-thiazolinyl)-3-thioacetic acid ester group azetidine (IV), in the presence of alkali, subjecting (IV) to hydrolysis and then to acidification with dilute hydrochloric acid, thus obtaining the 1-(4, 5-dihydro-2-thiazolinyl)-3-mercaptoazetidine hydrochloride (V). With easily available and inexpensive starting material, the method of the invention simplifies the synthesis route, improves the raw material utilization ratio and the overall yield. An intermediate obtained in the reaction can be subjected to refinement by a recrystallization method or to a next reaction directly, so that the yield is high and the "three wastes" produced during the reaction process are few. In addition, with low cost, the method of the invention is beneficial for industrial production.