Symmetrical derivatives of 1,4-distyrylbenzene belong to di~pers e optical brightening agents applied especially to polyester fibers. In addition the compounds of this type are used as potentiators in sensibilizatioll of photographic emulsions. No method of preparation of unsymmetrical derivatives of distyrylbenzene has been found yet, The symmetrical derivatives of 1,4-distyrylbenzene are prepared by reaction of benzyl- triphenylp"hosphonium halogenides or dialkyl ...