TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (Disclosed): The alkali metal salt or bisphenol, and dihalogenated compound substituted by halogen atom and nitrile are reacted, to obtain an aromatic compound (1). Preferred Compound: The aromatic compound is of formula (2) or (3). (formulae not reproduced due to lack of clarity in original patent specification)A,E,f,h,R',X,l,o,q,n and p=same as defined above;D=-direct bonding, -O-, -CO-, -(CH2)h-, or -CR2-;R=aliphatic hydrocarbon or aromatic hydrocarbon group;P'=structure chosen from the formulae (4-1) to (4-3);Q=structure chosen from the formula (5-1) to (5-12);andn=0.3-1.Preferred Unit: The polyarylene copolymer obtained using aromatic compound, contains halogen atom-containing structural unit (1') or halogen atom-containing structural unit of formula (6). (formulae not reproduced due to lack of clarity in original patent specification)A,D,E,B,R1-R28,o,m,q,n and p=same as defined above;Y'=-CO-, -SO2-, -SO-, -CONH-, -COO-, -(CF2)f- and/or -C(CF3)2-;Z=-(CH2)h-, -C(CH3)2-, -O- and/or -S-;Ar=-SO3H, -O(CH2)rSO3H or -O(CF2)rSO3H;R=1-12;j,k=0-10;andl=1-4. SPECIFIC COMPOUNDS - 10 examples of aromatic compound (1) such as 3-(3-t-butyl 5-methyl 4-hydroxy phenyl) propionate, 1,6-hexanedione bis(3-(3,5-di-t-butyl 4-hydroxyl phenyl) propionate), 2,4-bis(n-octyl thio)-6-(4-hydroxy 3,5-di-t-butyl anilinon)-3,5-triazine, pentaerythrityl tetrakis (3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate), and 2,2-thio diethylene bis(3-(3,5-di-t-butyl 4-hydroxy phenyl) propionate), are disclosed.    EXAMPLE - 4,4'-dichloro benzophenone (in g) (60.3), 4,4'-(1,4-phenylene diisopropylidene) bisphenol (69.3) and potassium carbonate (35.9) were mixed, and sulfolane (350 mL) and toluene (190 mL) were added to the mixture. The resultant mixture was heated and refluxed at 150 degrees C under nitrogen atmosphere, and water and toluene was removed. Then, 4,4'-dichloro benzophenone (20.1) was further added to the resultant mixture and stirred for 3 hour, and filtered to remove inorganic substance insoluble in the reaction solution. Subsequently, the filtrate was poured into methanol (2 L), and solidified. The precipitated solidified substance was filtered, washed and vacuum-dried. The dried product was dissolved in tetrahydrofuran (200 mL), filtered and further vacuum dried, and 92% yield of aromatic compound (1) (103) having number average molecular weight of 4500 and weight average molecular weight of 6800 was obtained. A proton conductive film formed using the obtained aromatic compound (1) had excellent membrane resistance, dimensional stability and low methanol permeability.