Synthesis and evaluation of a series of symmetrical hot brand bis azo reactive dyes using 4,4́-methylene-bismetanilic acid on various fibre

4,4́-methylene-bis-metanilic acid (a) was synthesized by the reaction between metanilic acid and formaldehyde. the compound (a) was used as a bifunctional middle component in the preparation of several symmetrical hot brand bis azo reactive dyes. the compound (a) was tetrazotized and coupled with various m-nitro anilino cyanurated coupling component to give various hot brand bis azo reactive dyes. the entired compounds have been identified by ir, 1h nmr spectra and elemental analysis. the dyes were applied on silk, wool and cotton fabrics and their fastness properties were evaluated. all the dyes give good fastness properties. the percentage dye bath exhaustion was also been studied.