A
reactive dye compound comprising: (a) at least one
chromophore moiety; (b) at least one SO2C2H4 group which is attached to the
chromophore moiety either directly via the sulphur atom of the SO2C2H4 group or a linking group L; characterised in that at least one SO2C2H4 group is substituted on its terminal
carbon atom with at least one Y group wherein Y is -A(CO)R* wherein A is selected from O or S and wherein R' contains at least one terminal nucleophilic group, such as OH, NH2, SH, COOH, N, NHR<1> and NR<1>R<2> wherein R<1> and R<2> may be the same or different and may be selected from C1-C4
alkyl; and salts thereof. Also claimed is a process of manufacture of the compounds herein and products obtainable by the process. The compounds herein have high Exhaustion Values (E), high Fixation Values (F) and high Efficiency Values (T) and show significant improvements in terms of reducing spent dyestuff in
effluent, increasing dye affinity to the substrate, increasing the dye-substrate covalent bonding, increasing the ability to dye substrates at
room temperature, decreasing the amount of dye that is removed during the post
dyeing 'soaping off process' and therefore simplifying the post
dyeing 'soaping off process' traditionally associated with
dyeing cotton with fibre reactive dyes and reduction of
staining of adjacent white fabrics. In addition, the compounds prepared above provide more intense dyeings and require less levels of salt for dyeing cotton substrates.