Abstract Condensation of 2-alkynyl-1-chloro-and 1-alkynyl-2-chloroanthraquinones with Na 2 S under mild conditions afforded anthra [1, 2-b] thiophene-6, 11-diones and anthra [2, 1-b] thiophene-6, 11-diones, respectively. A variety of angular anthrathiophenediones was synthesized by this method. The acetylenic precursors were prepared by a modified procedure of the Sonogashira reaction.
