Synthesis of sulfur isosteres of cholanthrene was written by Faller, Pierre. And the article was included in Comptes Rendus des Seances de l’Academie des Sciences, Serie C: Sciences Chimiques in 1966.Reference of 5118-13-8 This article mentions the following:
The synthesis of I and II is described. 4-Bromobenzo[b]thiophene (III), b20 144° [1,1-dioxo derivative m. 147° (EtOH)], was prepared from ο-BrC6H4CHO via the following intermediates: 5-(ο-bromobenzylidene)rhodanine, m. 189° (EtOH); ο-BrC6H4CH:C(SH)CO2H, m. 147°; [ο-BrC6H4CH:C(CO2H)S]2, m. 207° (EtOH); and 4-bromobenzo[b]-2-thienoic acid, m. 272° (EtOH). The Grignard reagent from I condensed with 4-cyanoindan and hydrolyzed gave IV, m. 88-9° (petroleum ether) [2,4-dinitrophenylhydrazone m. 234-5° (EtOH)], which subjected at 400-20° during 5-10 min. to an Elbs cyclodehydration under N yielded 10% II, m. 187-8° (EtOH-C6H6). 7-Br isomer of III yielded similarly V, m. 86.5° (petroleum ether) [2,4-dinitrophenylhydrazone m. 257° (EtOH-C6H6)], which was converted to 40% I, m. 172-3° (EtOH-C6H6); 2,4,7-trinitrofluorenone adduct m. 266° (absolute EtOH); picric acid adduct m. 149-50° (absolute EtOH); maleic anhydride adduct m. 251-2° (C6H6-petroleum ether). In the experiment, the researchers used many compounds, for example, 4-Bromobenzo[b]thiophene (cas: 5118-13-8Reference of 5118-13-8).
4-Bromobenzo[b]thiophene (cas: 5118-13-8) belongs to benzothiophene derivatives. Benzothiophene is relatively a stable molecule. The core structure is a part of various pharmaceutical substances and natural products. The different substitution patterns in these heterocycles offer new opportunities for drug discovery and other applications in materials science.Reference of 5118-13-8
Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem