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Synthesis of substituted benzo[ b ]thiophenes by acid‐catalyzed cyclization of thiophenylacetals and ketones
Author(s) -
Pié Patrick A.,
Marnett Lawrence J.
Publication year - 1988
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570250445
Subject(s) - chemistry , chlorobenzene , catalysis , medicinal chemistry , organic chemistry , nitro , alkyl
Benzo[ b ]thiophenes substituted at the 3 position with methyl or carboxymethyl and at the 5 position with methyl, methoxy, chloro, bromo and nitro were prepared by cyclization of thiophenyl‐acetals and ketones using a suspension of polyphosphoric acid in refluxing chlorobenzene. The overall efficiency of this method is superior to literature procedures because of the lower temperature and the limited amount of PPA used.