Bisdiazonium salts of 4,4'-diamino-3,3'-dialkoxybiphenyls and a process for their preparation

US4987221A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Hasso Hertel
• Klaus Hunger · Kelkheim, DE
• Heinrich Frolich · Niedernhausen, DE

Key dates

• Filing date: Mar 27, 1986
• Grant date: Jan 22, 1991
• Expiry date: Mar 27, 2006

Classification

• Technology area (CPC D): Textiles; Paper
• CPC primary: D06P1/12
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

Bisdiazonium salts of the formula (1) ##STR1## in which R denotes a linear or branched alkyl or alkoxyalkyl radical having 3-5 carbon atoms and X.sup.- represents the radical of a strong acid or of a zinc chloride double salt, and a process for their preparation by diazotizing a 4,4'-diamino-3,3'-dialkoxybiphenyl of the formula (2) ##STR2## in which R has the meaning mentioned, in an aqueous, strong, non-oxidizing inorganic or organic acid at temperatures from about -10.degree. C. to about +40.degree. C. by means of an alkali metal nitrite, and precipitating the resulting bisdiazonium salts by adding an alkali metal chloride, bisulfate, monosulfonate of 1,5-naphthalenedisulfonic acid or tetrafluoroborate or zinc chloride. These salts are useful in dyeing and printing textile fiber materials by the methods of the ice color technique, using suitable coupling components; they are also useful for preparing photographic tracings by the methods of reprography.