Angular polycyclic thiophenes containing two thiophene rings. I

Abstract We describe the synthesis of thieno[2,3‐c]dibenzothiophene (6), thieno[3,2‐c]dibenzothiophene (10), thieno‐[3,2‐a]dibenzothiophene (14), thieno[2,3‐a]dibenzothiophene (16), benzo[1,2‐b:4,3‐b]bisbenzo[b]thiophene (18), benzo[1,2‐‐6:3,4‐b]bisbenzo[b]thiophene (20), benzo[2,1‐‐6:3,4‐b]bisbenzo[b]thiophene (22), benzo[1,2‐b:3,4‐g]bisbenzo[b]thiophene (27), benzo[1,2‐b:4,3‐e]bisbenzo[b]thiophene (29), benzo[2,1‐‐6:3,4‐g]bisbenzo[b]thiophene (36), benzo[2,1‐‐6:4,3‐e]bisbenzo[b]thiophene (38), benzo[1,2‐‐6:4,3‐g]bisbenzo[b]thiophene (41), benzo[1,2‐b:4,5‐g]bisbenzo[b]thiophene (42), benzo[1,2‐b:3,4‐e]bisbenzo[b]thiophene (44) and benzo‐[1,2‐b:5,4‐e]bisbenzo[b]thiophene (45).