Abstract: A process for the preparation of sulphonated distyryl-biphenyl compounds of formula: ##STR1## in which R.sub.1 represents hydrogen, C.sub.1 -C.sub.5 alkyl, C.sub.1 -C.sub.5 alkoxy or halogen, R.sub.1A represents hydrogen, C.sub.1 -C.sub.5 alkyl, C.sub.1 -C.sub.5 alkoxy or halogen and M represents hydrogen, an alkaline- or alkaline earth-metal, or ammonium, characterised by reacting a compound of formula: ##STR2## in which R.sub.2 represents C.sub.1 -C.sub.5 alkyl, with a compound of formula: ##STR3## whereby R.sub.3 represents phenyl, optionally substituted by C.sub.1 -C.sub.4 alkoxy, halogen or SO.sub.3 M, or C.sub.1 -C.sub.12 alkyl, R.sub.4 represents C.sub.2 -C.sub.6 alkylene, and M, R.sub.1 and R.sub.1A are defined as above, in an alcoholic or dipolar aprotic solvent and in the presence of a strong base. Novel compounds of formulae (3) and (4) and a process for their preparation.