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

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.

Dependencies are inferred from the claim text.