Abstract: This invention relates to compounds which are valuable as a fluorescent brightener and a novel process for producing the same.The present invention is based on the following discoveries made by the inventors:In the presence of a palladium catalyst and a base at an elevated temperature, 1 mole of a compound of the formula,X--A--X (1)is reacted with 2 moles, in total, of one or two kinds of compounds selected from the group consisting of a styrene derivative having the formula, ##SPC1##And, thereby a compound of the formula, ##SPC2##Is obtained at a high yield, wherein, in the formula (1), X represents iodine or bromine, and A represents a bivalent radical selected from the group consisting of compounds of the formula, ##SPC3##And wherein, in the formula (2), R.sub.1 represents a substituent selected from the group consisting of hydrogen, chlorine, lower alkyl, methoxy, ethoxy, sulfonic acid radical or the salts thereof, sulfonamide radical, and lower-alkyl-substituted sulfonamide radical, and R.sub.