GB436805A - Manufacture of naphthylamine derivatives - Google Patents

Abstract

1-Hydroxyalkylamino-5-naphthols and (or) 1 : 5-di(hydroxyalkylamino)naphthalenes are prepared by treating 1 : 5-dihydroxynaphthalene with a primary hydroxyalkyl amine sulphite in an aqueous medium or with a primary hydroxyalkyl amine in the presence of an aqueous solution of a bisulphite. When a 1-hydroxyalkylamino-5-naphthol is the product desired, the corresponding 1 : 5-di(hydroxyalkylamino)naphthalene may be added to the reaction mixture, to restrain its formation in the reaction. The reaction may be effected under reflux or at 110--115 DEG C. under pressure. In the examples, (1) 1 : 5-dihydroxynaphthalene, ethanolamine, and aqueous sodium bisulphite are heated together and the product is diluted, made strongly alkaline, boiled and cooled, whereupon 1 : 5-di(hydroxyethylamino)-naphthalene separates; the filtrate is acidified to precipitate unchanged 1 : 5-dihydroxynaphthalene, and the filtrate from this is made feebly alkaline to precipitate 1-hydroxyethylamino-5-naphthol; ethanolamine sulphite may be used in place of ethanolamine and sodium bisulphite; (2) 1 : 5-dihydroxynaphthalene, ethanolamine, and aqueous sodium bisulphite are heated together with the addition of 1 : 5-di-(hydroxyethylamino)naphthalene, and the product is worked up as in example 1. Specification 410,843 is referred to.