As a kind of pyrithione salts, sodium pyrithione is currently used for anti-mildew and antibacterial products in the fields of daily chemical, architectural coatings, adhesives, sealants, pesticides, textiles, leather products, metalworking fluids, etc. Agents, detergents and medical broad-spectrum antifungal dermatology drugs.
At present, the synthetic route for sodium pyrithione salts mainly includes four kinds, the first one is 2-aminopyridine as a starting material; the second is pyridine-2-carboxylic acid as a starting material; the third is Starting from pyridine; the fourth is based on 2-chloropyridine. Among them, 2-aminopyridine as a starting material has a long synthetic route, which is subjected to acylation, oxidation, hydrolysis, diazotization, chlorination, thiolation, and then hydrolysis to obtain sodium pyrithione, and the total yield cannot be controlled.
When pyridine-2-carboxylic acid and pyridine are used as starting materials to produce the sodium salt of pyrithione salts, the reaction conditions are relatively demanding in this case, and the reaction process requires sodium hydride or lithium hydride and argon gas, which is difficult. Realize industrial production. At present, mainly domestically, 2-chloropyridine is used as a starting material, and sodium pyrithione is obtained by oxidation, thiolation and hydrolysis.www.china-zhufengchem.com