PRODUCTION OF 3-HYDROXY-1,4-NAPHTHOQUINONE-2-SULFONATE SALT

摘要

PURPOSE:The oxidation of naphthoquinonesulfonate salt or naphthohydroquinonesulfonate salt is carried out in an alkaline aqueous solution of ammonia to enable easy and high-yield production of the titled compound which is used as a redox catalyst. CONSTITUTION:The objective compound is obtained by oxidizing naphthoquinonesulfonate or naphthohydroquinonesulfonate salt in an aqueous ammonia- alkali solution using a gas containing oxygen, when necessary, in the presence of a compound of a metal which can have variable valencies such as iron or vanadium. The ammonia-alkaline aqueous solution is prepared by adjusting the pH of aqueous naphthoquinonesulfonate resulting from reaction between naphthoquinone and a bisulfite salt to over 9.8pH with ammonia or aqueous ammonia.