4-Bromobenzo[b]thiophene

The traditional synthesis method is to take 2-bromo-6-fluorobenzaldehyde as a raw material, cyclize the raw material with mercaptoacetic acid in a DMF solvent to obtain 4-chlorobenzo [b] thiophene-2-carboxylic acid, and then decarboxylate the product at a high temperature in a quinoline/copper powder system to obtain the 4-chlorobenzo [b] thiophene. 

4-Bromobenzo[b]thiophene is an important intermediate in the drug ipiprazole for the treatment of schizophrenia.

[1] Patent: US2017/158680, 2017, A1. Location in patent: Paragraph 0361; 0368; 0369
[2] Tetrahedron Letters, 2004, vol. 45, # 52, p. 9645 - 9647
[3] Organic Process Research and Development, 2012, vol. 16, # 8, p. 1449 - 1454
[4] Patent: WO2007/92751, 2007, A2. Location in patent: Page/Page column 20-21
[5] Patent: EP1724277, 2006, A1. Location in patent: Page/Page column 28-29