- Direct Carboxylation of Electron-Rich Heteroarenes Promoted by LiO-tBu with CsF and [18]Crown-6
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We herein demonstrate that the combination of LiO-tBu, CsF, and [18]crown-6 efficiently promotes the direct C?H carboxylation of electron-rich heteroarenes (benzothiophene, thiophene, benzofuran, and furan derivatives). A variety of functional groups, including methyl, methoxy, halo, cyano, amide, and keto moieties, are compatible with this system. The reaction proceeds via the formation of a tert-butyl carbonate species.
- Shigeno, Masanori,Hanasaka, Kazuya,Sasaki, Keita,Nozawa-Kumada, Kanako,Kondo, Yoshinori
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supporting information
p. 3235 - 3239
(2019/02/13)
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- Synthesis and structure-activity relationships of 5-phenylthiophenecarboxylic acid derivatives as antirheumatic agents
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5-(Phenylthiophene)-3-carboxylic acid (2a), a metabolite of esonarimod (1), which was developed as a new antirheumatic drug, was considered as a lead compound for new antirheumatic drugs. A new series of 2a derivatives were synthesized and their characteristic pharmacological effects, that is their antagonistic effect toward interleukin (IL)-1 in mice and the suppressive effect against adjuvant-induced arthritis (AIA) in rats, were evaluated and compared with those of 1. The structure-activity relationships indicated that [5-(4-bromophenyl)-thiophen-3-yl]acetic acid (5d), methyl [5-(4-chlorophenyl)-thiophen-3-yl]acetate (5h), and methyl [5-(4-bromophenyl)-thiophen-3-yl]acetate (5i) suppressed AIA more potently than 1 and all of the other synthesized compounds.
- Noguchi, Toshiya,Hasegawa, Masahiro,Tomisawa, Kazuyuki,Mitsukuchi, Morihiro
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p. 4729 - 4742
(2007/10/03)
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