Reference

Oxazine dyes for leather

Oxazine dyes for leather. Jauer, Ernst Adolf; Thurm, Hans; Scheffler, Heinz; Keil, Alfred; Oschatz, Siegfried (VEB Chemiekombinat Bitterfeld, Ger. Dem. Rep.). Ger. (East) DD 203065 A1 12 Oct 1983, 7 pp. (German). (German Democratic Republic). CODEN: GEXXA8. CLASS: IC: C09B019-00. APPLICATION: DD 81-232415 6 Aug 1981. DOCUMENT TYPE: Patent CA Section: 41 (Dyes, Organic Pigments, Fluorescent Brighteners, and Photographic Sensitizers) Section cross-reference(s): 45 Water-sol., yellowish brown leather dyes (I; R = NO2, Cl, CO2H) are prepd. by condensing 5,4,3-R(HO)(H2N)C6H2SO3H (R as previously defined) with 2,3,5-R2R3(O2N)C6H2SO3H (R2 = halogen; R3 = halogen, NO2) in aq. 96-93-5 and 89477-76-9 are cas registry numbers of chemicals which are used as reagents here. soln. at 350° and pH >4. Thus, 2,3,5-Cl(O2N)2C6H2SO3H [4515-26-8] was slowly added to a stirred aq. soln. of 3,4,5-H2N(HO)(HO2C)C6H2SO3H [6201-86-1] and Na2CO3 at 95-100° while maintaining pH 8 by addn. of Na2CO3. Further heating followed by salting pptd. the Na salt [89477-76-9] of I (R = CO2H). The dye showed good penetration when applied to leather. .