- From Oxadiazole to Triazole Analogues: Optimization toward a Dual Orexin Receptor Antagonist with Improved in vivo Efficacy in Dogs
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The orexin system is responsible for regulating the sleep-wake cycle. Suvorexant, a dual orexin receptor antagonist (DORA) is approved by the FDA for the treatment of insomnia disorders. Herein, we report the optimization efforts toward a DORA, where our starting point was (5-methoxy-4-methyl-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-[5-(2-trifluoromethoxy-phenyl)-[1,2,4]oxadiazol-3-yl]-pyrrolidin-1-yl}methanone (6), a compound which emerged from our in-house research program. Compound 6 was shown to be a potent, brain-penetrating DORA with in vivo efficacy similar to suvorexant in rats. However, shortcomings from low metabolic stability, high plasma protein binding (PPB), low brain free fraction (fu brain), and low aqueous solubility, were identified and hence, compound 6 was not an ideal candidate for further development. Our optimization efforts addressing the above-mentioned shortcomings resulted in the identification of (4-chloro-2-[1,2,3]triazol-2-yl-phenyl)-{(S)-2-methyl-2-[5-(2-trifluoromethoxy-phenyl)-4H-[1,2,4]triazol-3-yl]-pyrrolidin-1-yl}l-methanone (42), a DORA with improved in vivo efficacy compared to 6.
- Bolli, Martin H.,Boss, Christoph,Brotschi, Christine,Gatfield, John,Heidmann, Bibia,Jenck, Francois,Roch, Catherine,Sifferlen, Thierry,Treiber, Alexander,Williams, Jodi T.
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supporting information
(2020/01/25)
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- IrIII-Catalyzed Selective ortho-Monoiodination of Benzoic Acids with Unbiased C?H Bonds
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An iridium-catalyzed selective ortho-monoiodination of benzoic acids with two equivalent C?H bonds is presented. A wide range of electron-rich and electron-poor substrates undergo the reaction under mild conditions, with >20:1 mono/di selectivity. Importantly, the C?H iodination occurs selectively ortho to the carboxylic acid moiety in substrates bearing competing coordinating directing groups. The reaction is performed at room temperature and no inert atmosphere or exclusion of moisture is required. Mechanistic investigations revealed a substrate-dependent reversible C?H activation/protodemetalation step, a substrate-dependent turnover-limiting step, and the crucial role of the AgI additive in the deactivation of the iodination product towards further reaction.
- Weis, Erik,Johansson, Magnus J.,Martín-Matute, Belén
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supporting information
p. 10185 - 10190
(2020/07/31)
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- Oxadiazole Derivatives as Dual Orexin Receptor Antagonists: Synthesis, Structure–Activity Relationships, and Sleep-Promoting Properties in Rats
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The orexin system plays an important role in the regulation of wakefulness. Suvorexant, a dual orexin receptor antagonist (DORA) is approved for the treatment of primary insomnia. Herein, we outline our optimization efforts toward a novel DORA. We started our investigation with rac-[3-(5-chloro-benzooxazol-2-ylamino)piperidin-1-yl]-(5-methyl-2-[1,2,3]triazol-2-ylphenyl)methanone (3), a structural hybrid of suvorexant and a piperidine-containing DORA. During the optimization, we resolved liabilities such as chemical instability, CYP3A4 inhibition, and low brain penetration potential. Furthermore, structural modification of the piperidine scaffold was essential to improve potency at the orexin 2 receptor. This work led to the identification of (5-methoxy-4-methyl-2-[1,2,3]triazol-2-ylphenyl)-{(S)-2-[5-(2-trifluoromethoxyphenyl)-[1,2,4]oxadiazol-3-yl]pyrrolidin-1-yl}methanone (51), a potent, brain-penetrating DORA with in vivo efficacy similar to that of suvorexant in rats.
- Brotschi, Christine,Roch, Catherine,Gatfield, John,Treiber, Alexander,Williams, Jodi T.,Sifferlen, Thierry,Heidmann, Bibia,Jenck, Francois,Bolli, Martin H.,Boss, Christoph
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supporting information
p. 1257 - 1270
(2019/06/17)
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- Palladium-Catalyzed β-C?H Arylation of Ketones Using Amino Amide as a Transient Directing Group: Applications to Synthesis of Phenanthridinone Alkaloids
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The direct arylation of aromatic and aliphatic ketones was carried out via palladium-catalyzed inert C?H bond functionalization with 2-amino-N-isopropyl-acetamide as a new catalytic transient directing group. The reaction showed excellent functional group compatibility and site selectivity. We demonstrated that α-amino amide forming N,N-bidentate coordination with Pd catalyst is more favorable for the β-arylation of ketones than α-amino acid forming N,O-bidentate coordination with Pd catalyst under relatively mild conditions. This elegant approach provides straightforward access to important structural motifs in organic and medicinal chemistry and is demonstrated here in the efficient synthesis of phenanthridinone alkaloids. (Figure presented.).
- Wang, Junliang,Dong, Cong,Wu, Liangfei,Xu, Mingkai,Lin, Jun,Wei, Kun
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supporting information
p. 3709 - 3715
(2018/09/14)
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- Copper-Catalyzed C(sp3)-S Bond and C(sp2)-S Bond Cross-Coupling of 2-(2-Iodobenzoyl) Substituted or 2-(2-Iodobenzyl) Substituted 1,2,3,4-Tetrahydroisoquinolines with Potassium Sulfide: Synthesis of Isoquinoline-Fused 1,3-Benzothiazine Scaffolds
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The sulfuration reaction of 2-(2-iodobenzoyl) substituted, or 2-(2-iodobenzyl) substituted 1,2,3,4-tetrahydroisoquinolines with potassium sulfide proceeded in the presence of copper catalysts to give tetrahydroisoquinoline-fused 1,3-benzothiazine scaffolds in moderate to appropriate yields. This protocol provided an efficient and simple strategy to construct the corresponding benzothiazine derivatives via formation of C(sp3)-S bond and C(sp2)-S bond, which the C-S bonds formed via different routes in this reaction (traditional cross-coupling reaction via the cleavage of C-I bond and oxidative cross-coupling reaction via C(sp3)-H bond functionalization).
- Dang, Pan,Zheng, Zhilei,Liang, Yun
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p. 2263 - 2268
(2017/02/26)
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- 2-iodoxybenzenesulfonic acid as an extremely active catalyst for the selective oxidation of alcohols to aldehydes, ketones, carboxylic acids, and enones with oxone
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Electron-donating group-substituted 2-iodoxybenzoic acids (IBXs) such as5-Me-IBX (1g), 5-MeO-IBX (1h), and 4,5-Me2-IBX were superior to IBX 1a as catalysts for the oxidation of alcohols with Oxone (a trad emark of DuPont) under nonaqueous conditions, although Oxone was almost insoluble in most organic solvents. The catalytic oxidation proceeded more rapidly and cleanly in nitromethane. Furthermore, 2-iodoxybenzenesulfonic acid (IBS, 6a) was much more active than modified IBXs. Thus, we established a highly efficient and selective method for the oxidation of primary and secondary alcohols to carbonyl compounds such as aldehydes, carboxylic acids, and ketones with Oxone in nonaqueous nitromethane, acetonitrile, or ethyl acetate in the presence of 0.05-5molpercentof 6a, which was generated in situ from 2-iodobenzenesulfonic acid (7a) or its sodium salt. Cycloalkanones could be further oxidized to α,β- cycloalkenones or lactones by controlling the amounts of Oxone under the same conditions as above. When Oxone was used under nonaqueous conditions, Oxone wastes could be removed by simple filtration. Based on theoretical calculations, we considered that the relatively ionic character of the intramolecular hypervalent iodine-OSO2 bond of IBS might lower the twisting barrier of the alkoxyperiodinane intermediate 16.
- Uyanik, Muhammet,Akakura, Matsujiro,Ishihara, Kazuaki
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supporting information; experimental part
p. 251 - 262
(2009/06/28)
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- Lodination of deactivated aromatic compounds with iodine chloride
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Iodine(I) chloride reacts with deactivated arenes in sulfuric acid to give the corresponding aryl iodides whose yield strongly depends on the concentration of H2SO4. The optimal concentration of the latter was determined for iodination of aromatic carboxylic acids and halobenzenes. 1998 MAHK Hayka/Interperiodica Publishing.
- Chaikovskii,Filimonov,Kulupanova,Chernova
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p. 997 - 999
(2007/10/03)
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- Synthesis of 4-Alkyl-2-iodosobenzoic Acids: Potent Catalysts for the Hydrolysis of Phosphorous Esters
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The syntheses of five new 4-alkyl-2-iodosobenzoic acids (3) are described.The iodine atom was introduced by ortho-directed lithiation of 4-alkylbenzyl alcohols followed by treatment with I2.The catalytic effectiveness of each of the products in the hydrolysis of 4-nitrophenyl diphenyl phosphate in microemulsions was studied.The 4-methyl- and 4-ethyl-substituted products were each found to be significantly better catalysts than the standard nonalkylated 2-iodosobenzoic acid (3, R=H).These results would indicate that microemulsions of these materials may find use in detoxification procedures.
- Panetta, Charles A.,Garlick, Stephanie M.,Durst, H. Dupont,Longo, Frederick R.,Ward, J. Richard
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p. 5202 - 5205
(2007/10/02)
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