An efficient novel synthesis of β-(azuleno[1,2-b]benzothienyl)- and β-(azuleno[2,1-b]benzothienyl)-α,β-unsaturated ketones by the tropylium ion-mediated intramolecular furan ring-opening reaction and X-ray investigation of methyl ketone derivative was written by Yamamura, Kimiaki;Houda, Yuuko;Hashimoto, Masao;Kimura, Takatomo;Kamezawa, Makoto;Otani, Takehiko. And the article was included in Organic & Biomolecular Chemistry in 2004.Product Details of 6287-82-7 This article mentions the following:
Intramol. reaction of 2-tropylio-3-(5-substituted 2-furyl)benzothiophenes, prepared from the corresponding 2-cycloheptatrienyl-3-(5-substituted 2-furyl)benzothiophenes, afforded the β-(azuleno[1,2-b]benzothienyl)-α,β-unsaturated ketones, e.g., I, which are otherwise difficult to obtain, in moderate yields. The reaction involves a ring-opening process of the furan ring by intramol. attack of the tropylium ion onto the 2-position of the furan ring. Similarly, β-(azuleno[2,1-b]benzothienyl)-α,β-unsaturated ketones were obtained from the corresponding 3-tropylio-2-(5-substituted 2-furyl)benzothiophenes albeit in lower yields. The mol. and crystal structures of the Me ketone derivative, 8a, are discussed on the basis of X-ray structure anal. In the experiment, the researchers used many compounds, for example, 2,3-Dibromobenzo[b]thiophene (cas: 6287-82-7Product Details of 6287-82-7).
2,3-Dibromobenzo[b]thiophene (cas: 6287-82-7) belongs to benzothiophene derivatives. Benzothiophene finds use in research as a starting material for the synthesis of larger, usually bioactive structures. The different substitution patterns in these heterocycles offer new opportunities for drug discovery and other applications in materials science.Product Details of 6287-82-7
Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem