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Convenient and Efficient Synthesis of 11‐Amino‐2,8‐substituted‐2,3,8,9‐tetrahydrobenzo[4,5]thieno[2,3‐ b ]quinolinone Derivatives
Author(s) -
Wang ZhongXia,
Chen LiZhuang,
Li Bei,
Han GuangFan
Publication year - 2015
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.2200
Subject(s) - chemistry , malononitrile , sulfur , hydrochloric acid , catalysis , thiophene , proton nmr , medicinal chemistry , elemental analysis , nmr spectra database , organic chemistry , spectral line , physics , astronomy
The Gewald reactions of 5‐substituted‐1,3‐cyclohexanedione, malononitrile, and powdered sulfur were carried out to give the corresponding products 2‐amino‐5‐substituted‐7‐oxo‐4,5,6,7‐tetrahydrobenzo[ b ]thiophene‐3‐carbonitrile derivatives 1 . The intermediate enamines 2 were prepared by reaction of compounds 1 and 5‐substituted‐1,3‐cyclohexanedione with hydrochloric acid as catalyst. The title compounds 11‐amino‐2,8‐substituted‐2,3,8,9‐tetrahydrobenzo[4,5]thieno[2,3‐ b ]quinolinone 3 were synthesized by cyclization of compounds 2 in the presence of K 2 CO 3 and Cu 2 Cl 2 . The structures of all compounds were characterized by elemental analysis, IR, MS, and 1 H‐NMR spectra.