New methods for the synthesis of 4H‐dithieno[3,2‐b:2′,3′‐d]pyrrole

Various alternative methods for the synthesis of 4H‐dithieno[3,2‐b:2′,3′‐d]pyrrole (DTP) starting from commercially available bromothiophene precursors are presented. Crucial steps involve the Cadogan reaction, Ullmann‐type C─N couplings, or Buchwald‐Hartwig–type aminations to build up the central pyrrole ring of DTP, respectively. The use of ammonia surrogates afforded the fused target heteroacene in overall yields of 33% to 63%, and the corresponding methods are applicable on large scale.