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 ).