Method of preparing 1,6-di(N.sup.3 -cyano-N.sup.1 -guanidino) hexane

US5041655A · kind A · utility

Assignee

• Degussa AG · DE

Inventors

• Klaus Huthmacher · Gelnhausen, DE
• Axel Kleemann · Hanau, DE
• Horst Bethge · Hanau, DE
• Rolf Braun · Offenbach, DE

Key dates

• Filing date: Sep 6, 1988
• Grant date: Aug 20, 1991
• Expiry date: Sep 6, 2008

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C279/28
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

An improved method of preparing 1,6-di(N.sup.3 -cyano-N.sup.1 -guanidino) hexane from alkali dicyanamide and a hexamethylene diammonium salt in alcoholic solution or suspension. The reaction is carried out in the presence of a limited amount of water and of a catalytic amount of a base, preferably a tertiary amine. The pH of the reaction mixture at the start of the reaction is 8 to 10. After the reaction is over, the reaction mixture is compounded with water at a temperature above 80.degree. C. and the coarse product which crystallizes out is separated from the liquid phase. Preferably, sodium dicyanamide and hexamethylene diamine dihydrochloride, preferably formed in situ from aqueous 1,6-diaminohexane and aqueous hydrochloric acid, are reacted at pH 9-9.5 in n-butanol in the presence of 0.1 to 20% by wt. water in relation to the solvent including water. 1,6-di(N.sup.3 -cyano-N.sup.1 -guanidino) hexane is obtained in a high yield (85-86%) and with great purity (95-97%) and with a considerably improved space-time yield.