The Synthesis Process Research Of 3-Mercapto-1-Propanol

3-mercapto-1-propanol is a polymerized and vulcanized regulators for the production of synthetic rubber; It can be used as organic synthetic intermediate for the synthesis of pharmaceuticals, dyes and pesticides; moreover it can also be used as metal surface hardening agent, organic additive agent, modifier agent, metal corrosion inhibitor and traceless linker molecules for the synthesis of oligosaccharides using enzymatic and chemical method and so on. In addition, it can also make a contribution to the preparation of hydrophilic self-assembly monomolecular layer, anti-oxidant and catalyst, such as antioxidant-565 and iridium. Nowadays domestic 3-mercapto-1-propanol mainly relied on imports, which is very expensive, so it’s necessary for researchers to develop a new route for industrialization production.Firstly, 3-halogen-1-propanol, as a raw material of 3-mercapto-1-propanol, was obtained from 1,3-propylene glycol, the condition were determined as follows:3-bromine-1-alcohol(objective product) was obtained from 3-bromo propyl acetate in methanol under the existence of strong acid cation exchange resin, which was synthesized in toluene with 1,3-propylene glycol, hydrobromic acid and acetic acid as raw materials. The purity and yield were 95.51% and 83.88%, respectively. Its structure was confirmed by FT-IR.3-chloride-1-alcohol was synthesized under the existence of carboxylic acid catalyst with 1,3-propylene glycol, HCl as raw materials. The purity was 96% with 78.16% yield. Its structure was confirmed by FT-IR.Then, the synthesis route of 3-thiol-1-alcohol was investigated :S-isothiuronium propyl alcohol hydrobromide was synthesized with 3-bromo-1-propyl and thiourea by reflux reaction for approximately 12 h, in the presence of phase transfer catalyst dihexadecyl dimethyl ammonium chloride. The yield of S-isothiuronium propyl alcohol hydrobromide was 80.70%(MP 93.7-94.8 ℃). Its structure was confirmed by H-NMR and MS. Then S- isothiuronium propyl alcohol hydrobromide was hydrolyzed in the solution of NaOH for about 2.5 h to obtain 3-mercapto-1-propanol with 77.22% yield and 95% purity. The structure was confirmed by FT-IR and MS.In the other way, S- isothiuronium propyl alcohol hydrochloride was produced by 3-chloride-1-alcoho and thiourea as raw materials for about 14 h. The yield was about 72.82%(MP 113.8-114.7 ℃). Its structure was confirmed by H-NMR and MS. Then 3-mercapto-1-propanol was produced with 77.32% yield and 98% purity.3-bromine-1-alcohol route has the character of high yield and more reaction steps. Compared with the former, 3-chloride-1-propyl route shows lower cost and simplicity. But, the environmental issues should be paid attention.