Naturalised dyes: a simple straightforward synthetic route to a new class of dyes - Glycoazodyes (GADs)

We report a process to naturalise synthetic azodyes through their linkage with lactose, or its monosaccharide components, either galactose or glucose, to enhance their solubility, as many other natural dyes. This modification allows the dyeing process of textile materials to take place in water without the addition of surfactants or other additives. The synthesis of the first generation of glycoazodyes (GADs) is carried out with the use of a diester linker to bond the azodye and the sugar. Preliminary tinctorial tests showed that this first generation of GADs is soluble in water and that these new dyes are multipurpose and are able to dye different fabrics well.