Silica gel-assisted preparation of 2,4,7-trihalobenzo[b]thiophenes and 4,7-dihalobenzo[b]thiophenes

Shinichi Mikami, Hiroki Tanaka, Hiroki Kishi, Shuhei Yoshida, Kozo Toyota

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

All 6 isomers of (bromo)(chloro)(iodo)benzo[b]thiophenes containing three different halogen atoms at the 2-, 4- and 7-positions were synthesized from the corresponding 2-(1-adamantylsulfanyl)-1,4-dihalo-3-(haloethynyl)benzene derivatives, through treatment with silica gel under thermal conditions. In contrast to our previous method using gold chloride catalyst, migration of adamantyl group did not occur in this method using silica gel. Moreover, by using this method, we synthesized 6 types of 4,7-dihalobenzo[b]thiophenes in 4 steps from 2-fluoro-3,6-dihalo-benzaldehydes in moderate to excellent overall yields, 42–82%.

Original languageEnglish
Pages (from-to)768-770
Number of pages3
JournalPhosphorus, Sulfur and Silicon and the Related Elements
Volume194
Issue number7
DOIs
Publication statusPublished - 2019 Jul 3

Keywords

  • Multihalo-benzo[b]thiophene
  • facile cyclization
  • fused thiophene
  • heterocycle
  • quasi T-shape molecular scaffold

ASJC Scopus subject areas

  • Biochemistry
  • Organic Chemistry
  • Inorganic Chemistry

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