1-Propanethiol,2,3-bis[(2-mercaptoethyl)thio]- synthesis

Yield:131538-00-6 87.7%

Reaction Conditions:

Stage #1: 2-hydroxyethanethiol;epichlorohydrinwith sodium hydroxide in water at 30; for 4.5 h;
Stage #2: with hydrogenchloride;thiourea in water at 110; for 3 h;
Stage #3: with ammonium hydroxide in toluene at 60;

Steps:

4 Example 4.

In a 2 L four-necked reaction flask equipped with a stirrer, reflux cooled water separator, a nitrogen gas purge tube, and a thermometer, 169 parts by weight (2.16 mol) of 2-mercaptoethanol and 76.0 parts by weight of water were added. Thereafter, the reaction flask was heated to 30 ° C, and 91.9 parts by weight (1.08 mol) of 47% by weight aqueous sodium hydroxide solution was added dropwise for 30 minutes. Thereafter, 99.9 parts by weight (1.08 mol) of epichlorohydrin was added dropwise for 3 hours, and aged for 1 hour. Then, 450.0 parts by weight (4.32 mol) of 35% by weight aqueous hydrochloric acid, And purified thiourea aqueous solution of Preparation Example 1 (271.8 parts by weight of thiourea (3.56 mol) and 2,000 parts by weight of water) was added, and Thiuronium chloride was aged for 3 hours at reflux at 110 . After cooling the reaction flask to 60 , and then 450.0 parts by weight of toluene and 331.1 parts (4.86 mol) of 25% by weight aqueous ammonia were added and hydrolysed, and Toluene solution of polythiol having 1,2-bis [(2-mercaptoethyl) thio] -3-mercaptopropane as a main component was obtained. The toluene solution was acid washed and water washed, heated to 50 ° C. and decompressed to 1 torr to remove toluene and traces of water. Hereafter, Filtration gave 268.7 parts by weight of polythiol having 1,2-bis [(2-mercaptoethyl) thio] -3-mercaptopropane as a main component. APHA of the obtained polythiol was 10, and b * value was 0.62.

References:

KR102036246,2019,B1 Location in patent:Paragraph 0123-0126; 0160