Aromatic poly(arylene thioether)s were synthesized from N-propyl-S-carbamate-protected aromatic dithiols and aromatic difluorides. The deprotection of the protected dithiols with an organic base such as 1,8-diazabicyclo[5.4.0]-7-undecene at room temperature and subsequent polymerization with the difluoride monomers at 120 degrees C in N-methyl-2-pyrrolidinone produced high molecular weight polymers with intrinsic viscosities as high as 0.45 dL/g. The use of organic bases instead of inorganic bases for the generation of thiophenoxide nucleophile was a convenient way of avoiding metallic impurities in the synthesis of the poly(arylene thioether)s through a nucleophilic aromatic substitution reaction. (c) 2005 Wiley Periodicals, Inc.