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Lee SJ, Morales-Colón MT, Brooks AF, Wright JS, Makaravage KJ, Scott PJH, Sanford MS. S NAr Radiofluorination with In Situ Generated [ 18F]Tetramethylammonium Fluoride. J Org Chem 2021; 86:14121-14130. [PMID: 34505779 DOI: 10.1021/acs.joc.1c01491] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This report describes a method for the nucleophilic radiofluorination of (hetero)aryl chlorides, (hetero)aryl triflates, and nitroarenes using a combination of [18F]KF·K2.2.2 and Me4NHCO3 for the in situ formation of a strongly nucleophilic fluorinating reagent (proposed to be [18F]Me4NF). This method is applied to 24 substrates bearing diverse functional groups, and it generates [18F](hetero)aryl fluoride products in good to excellent radiochemical yields in the presence of ambient air/moisture. The reaction is applied to the preparation of 18F-labeled HQ-415 for potential (pre)clinical use.
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Affiliation(s)
- So Jeong Lee
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States.,Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114,United States
| | - María T Morales-Colón
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Allen F Brooks
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Jay S Wright
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Katarina J Makaravage
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Peter J H Scott
- Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Melanie S Sanford
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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2
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Katoh T. Facile Preparation of 3-Substituted-2,6-difluoropyridines and Application to the Synthesis of 2,3,6-Trisubstituted Pyridines for PKCθ Inhibitors. J SYN ORG CHEM JPN 2020. [DOI: 10.5059/yukigoseikyokaishi.78.121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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3
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Zhao XZ, Smith SJ, Maskell DP, Métifiot M, Pye VE, Fesen K, Marchand C, Pommier Y, Cherepanov P, Hughes SH, Burke TR. Structure-Guided Optimization of HIV Integrase Strand Transfer Inhibitors. J Med Chem 2017; 60:7315-7332. [PMID: 28737946 PMCID: PMC5601359 DOI: 10.1021/acs.jmedchem.7b00596] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Integrase mutations can reduce the effectiveness of the first-generation FDA-approved integrase strand transfer inhibitors (INSTIs), raltegravir (RAL) and elvitegravir (EVG). The second-generation agent, dolutegravir (DTG), has enjoyed considerable clinical success; however, resistance-causing mutations that diminish the efficacy of DTG have appeared. Our current findings support and extend the substrate envelope concept that broadly effective INSTIs can be designed by filling the envelope defined by the DNA substrates. Previously, we explored 1-hydroxy-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamides as an INSTI scaffold, making a limited set of derivatives, and concluded that broadly effective INSTIs can be developed using this scaffold. Herein, we report an extended investigation of 6-substituents as well the first examples of 7-substituted analogues of this scaffold. While 7-substituents are not well-tolerated, we have identified novel substituents at the 6-position that are highly effective, with the best compound (6p) retaining better efficacy against a broad panel of known INSTI resistant mutants than any analogues we have previously described.
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Affiliation(s)
| | | | - Daniel P Maskell
- Chromatin Structure and Mobile DNA, The Francis Crick Institute , London NW1 1AT, United Kingdom
| | - Mathieu Métifiot
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda, Maryland 20892, United States
| | - Valerie E Pye
- Chromatin Structure and Mobile DNA, The Francis Crick Institute , London NW1 1AT, United Kingdom
| | - Katherine Fesen
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda, Maryland 20892, United States
| | - Christophe Marchand
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda, Maryland 20892, United States
| | - Yves Pommier
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda, Maryland 20892, United States
| | - Peter Cherepanov
- Chromatin Structure and Mobile DNA, The Francis Crick Institute , London NW1 1AT, United Kingdom.,Imperial College London , St-Mary's Campus, Norfolk Place, London W2 1PG, United Kingdom
| | - Stephen H Hughes
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda, Maryland 20892, United States
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4
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Katoh T, Tomata Y, Setoh M, Sasaki S, Takai T, Yoshitomi Y, Yukawa T, Nakagawa H, Fukumoto S, Tsukamoto T, Nakada Y. Practical application of 3-substituted-2,6-difluoropyridines in drug discovery: Facile synthesis of novel protein kinase C theta inhibitors. Bioorg Med Chem Lett 2017; 27:2497-2501. [PMID: 28400232 DOI: 10.1016/j.bmcl.2017.03.099] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 03/30/2017] [Accepted: 03/31/2017] [Indexed: 12/11/2022]
Abstract
We previously reported a facile preparation method of 3-substituted-2,6-difluoropyridines, which were easily converted to 2,3,6-trisubstituted pyridines by nucleophilic aromatic substitution with good regioselectivity and yield. In this study, we demonstrate the synthetic utility of 3-substituted-2,6-difluoropyridines in drug discovery via their application in the synthesis of various 2,3,6-trisubstituted pyridines, including macrocyclic derivatives, as novel protein kinase C theta inhibitors in a moderate to good yield. This synthetic approach is useful for the preparation of 2,3,6-trisubstituted pyridines, which are a popular scaffold for drug candidates and biologically attractive compounds.
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Affiliation(s)
- Taisuke Katoh
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan.
| | - Yoshihide Tomata
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Masaki Setoh
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Satoshi Sasaki
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Takafumi Takai
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Yayoi Yoshitomi
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Tomoya Yukawa
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Hideyuki Nakagawa
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Shoji Fukumoto
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Tetsuya Tsukamoto
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Yoshihisa Nakada
- Pharmaceutical Research Division, Takeda Pharmaceutical Company, Ltd, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
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5
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Facile preparation of 3-substituted-2,6-difluoropyridines: application to the synthesis of 2,3,6-trisubstituted pyridines. Tetrahedron Lett 2015. [DOI: 10.1016/j.tetlet.2015.09.057] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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6
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Just-Baringo X, Albericio F, Álvarez M. From 2,6-Dichloronicotinic Acid to Thiopeptide Cores. European J Org Chem 2013. [DOI: 10.1002/ejoc.201300877] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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7
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Bach P, Marczynke M, Giordanetto F. Effects of the Pyridine 3-Substituent on Regioselectivity in the Nucleophilic Aromatic Substitution Reaction of 3-Substituted 2,6-Dichloropyridines with 1-Methylpiperazine Studied by a Chemical Design Strategy. European J Org Chem 2012. [DOI: 10.1002/ejoc.201200978] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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8
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Scott JS, Bowker SS, Deschoolmeester J, Gerhardt S, Hargreaves D, Kilgour E, Lloyd A, Mayers RM, McCoull W, Newcombe NJ, Ogg D, Packer MJ, Rees A, Revill J, Schofield P, Selmi N, Swales JG, Whittamore PRO. Discovery of a potent, selective, and orally bioavailable acidic 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) inhibitor: discovery of 2-[(3S)-1-[5-(cyclohexylcarbamoyl)-6-propylsulfanylpyridin-2-yl]-3-piperidyl]acetic acid (AZD4017). J Med Chem 2012; 55:5951-64. [PMID: 22691057 DOI: 10.1021/jm300592r] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Inhibition of 11β-HSD1 is an attractive mechanism for the treatment of obesity and other elements of the metabolic syndrome. We report here the discovery of a nicotinic amide derived carboxylic acid class of inhibitors that has good potency, selectivity, and pharmacokinetic characteristics. Compound 11i (AZD4017) is an effective inhibitor of 11β-HSD1 in human adipocytes and exhibits good druglike properties and as a consequence was selected for clinical development.
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Affiliation(s)
- James S Scott
- Cardiovascular and Gastrointestinal Innovative Medicines Unit, AstraZeneca Mereside, Alderley Park, Macclesfield, Cheshire, SK10 4TG, UK.
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9
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Teague SJ. Synthesis of heavily substituted 2-aminopyridines by displacement of a 6-methylsulfinyl group. J Org Chem 2009; 73:9765-6. [PMID: 18855484 DOI: 10.1021/jo801303v] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
2-Aminopyridines, with a variety of polar 6-substituents, were elaborated by displacement of a methylsulfinyl group from the 6-position of the pyridine ring. The requisite 6-thiomethyl pyridines were synthesized by reaction of 2-(1-phenylethylidene)propanedinitriles with dimethyl N-cyanodithioiminocarbonate.
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Affiliation(s)
- Simon J Teague
- Department of Medicinal Chemistry, AstraZeneca R&D Charnwood, Bakewell Road, Loughborough, UK.
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10
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Ando M, Sato N, Nagase T, Nagai K, Ishikawa S, Takahashi H, Ohtake N, Ito J, Hirayama M, Mitobe Y, Iwaasa H, Gomori A, Matsushita H, Tadano K, Fujino N, Tanaka S, Ohe T, Ishihara A, Kanatani A, Fukami T. Discovery of pyridone-containing imidazolines as potent and selective inhibitors of neuropeptide Y Y5 receptor. Bioorg Med Chem 2009; 17:6106-22. [DOI: 10.1016/j.bmc.2009.05.069] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 05/27/2009] [Accepted: 05/28/2009] [Indexed: 11/16/2022]
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11
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Development of practical syntheses of potent non-nucleoside reverse transcriptase inhibitors. Tetrahedron 2009. [DOI: 10.1016/j.tet.2009.03.084] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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12
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Zhong YL, Lindale MG, Yasuda N. An efficient access to 3,6-disubstituted 1H-pyrazolo[3,4-b]pyridines via a one-pot double SNAr reaction and pyrazole formation. Tetrahedron Lett 2009. [DOI: 10.1016/j.tetlet.2009.02.142] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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13
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Hussain I, Yawer MA, Lalk M, Lindequist U, Villinger A, Fischer C, Langer P. Hetero-Diels-Alder reaction of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with arylsulfonylcyanides. Synthesis and antimicrobial activity of 4-hydroxy-2-(arylsulfonyl)pyridines. Bioorg Med Chem 2008; 16:9898-903. [PMID: 18990580 PMCID: PMC7125755 DOI: 10.1016/j.bmc.2008.10.033] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2008] [Revised: 10/10/2008] [Accepted: 10/14/2008] [Indexed: 11/06/2022]
Abstract
Hetero-Diels-Alder reactions of 1,3-bis(silyloxy)-1,3-butadienes with arylsulfonylcyanides afforded a variety of 4-hydroxy-2-(arylsulfonyl)pyridines. Several derivatives show antimicrobial activity against Gram-positive bacteria.
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Affiliation(s)
- Ibrar Hussain
- Institut für Chemie, Universität Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
| | - Mirza Arfan Yawer
- Institut für Chemie, Universität Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
| | - Michael Lalk
- Institut für Pharmazie, Ernst-Moritz-Arndt-Universität Greifswald, F.-L.-Jahn-Str. 17, 17487 Greifswald, Germany
| | - Ulrike Lindequist
- Institut für Pharmazie, Ernst-Moritz-Arndt-Universität Greifswald, F.-L.-Jahn-Str. 17, 17487 Greifswald, Germany
| | - Alexander Villinger
- Institut für Chemie, Universität Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
| | - Christine Fischer
- Leibniz-Institut für Katalyse e. V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059 Rostock, Germany
| | - Peter Langer
- Institut für Chemie, Universität Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
- Leibniz-Institut für Katalyse e. V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059 Rostock, Germany
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14
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Ma M, Li C, Li X, Wen K, Liu YA. Efficient synthesis of 6-aryl-2-chloronicotinic acids via pd catalyzed regioselective suzuki coupling of 2,6-dichloronicotinic acid. J Heterocycl Chem 2008. [DOI: 10.1002/jhet.5570450646] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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15
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Shi YJ, Humphrey G, Maligres P, Reamer R, Williams J. Highly Regioselective DABCO-Catalyzed Nucleophilic Aromatic Substitution (SNAr) Reaction of Methyl 2,6-Dichloronicotinate with Phenols. Adv Synth Catal 2006. [DOI: 10.1002/adsc.200505431] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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16
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Yang W, Wang Y, Corte JR. Efficient synthesis of 2-aryl-6-chloronicotinamides via PXPd2-catalyzed regioselective Suzuki coupling. Org Lett 2003; 5:3131-4. [PMID: 12916999 DOI: 10.1021/ol035188g] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text] A short and convergent synthesis of 2-aryl-6-chloronicotinamides via regioselective Suzuki coupling of 2,6-dichloronicotinamide with aryl boronic acids is described. Regioselectivity was achieved by chelation of the palladium(0) species to an ester/amide group. The air-stable palladium catalyst PXPd2, when used in reagent-grade methanol with K(2)CO(3) as the base, afforded the best regioselectivity and shortest reaction times among the catalysts screened.
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Affiliation(s)
- Wu Yang
- Bristol-Myers Squibb Pharmaceutical Research Institute, P.O. Box 5400, Princeton, New Jersey 08543-5400, USA.
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17
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Hirokawa Y, Fujiwara I, Suzuki K, Harada H, Yoshikawa T, Yoshida N, Kato S. Synthesis and structure-affinity relationships of novel N-(1-ethyl-4-methylhexahydro-1,4-diazepin-6-yl)pyridine-3-carboxamides with potent serotonin 5-HT3 and dopamine D2 receptor antagonistic activity. J Med Chem 2003; 46:702-15. [PMID: 12593651 DOI: 10.1021/jm020270n] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A structurally original series of N-(1-ethyl-4-methylhexahydro-1,4-diazepin-6-yl)pyridine-3-carboxamides derived from the corresponding benzamide 5 were prepared and evaluated for their binding affinity for the dopamine D(2) and serotonin 5-HT(3) receptors using rat striatum and rat cortical membrane, respectively. Many of the synthesized pyridine-3-carboxamides exhibited nanomolar binding affinity for the serotonin 5-HT(3) receptor along with moderate to high binding affinity for the dopamine D(2) receptor. Introduction of the more lipophilic bromine atom and methylamino group at the 5- and 6-positions of the pyridine ring, respectively, enhanced the affinity for the dopamine D(2) receptor while keeping a potent serotonin 5-HT(3) receptor binding affinity. As a result of structure-affinity relationships, the 5-bromo-2-methoxy-6-methylaminopyridine-3-carboxamide 53 was selected as the most promising product showing a high binding affinity for both receptors. Compound 53 affinity for the dopamine D(2) and serotonin 5-HT(3) receptors was much more potent than that of metoclopramide (dopamine D(2) receptor; 23.3 nM vs 444 nM, serotonin 5-HT(3) receptor; 0.97 nM vs 228 nM). Optical resolution of the racemate 53 brought about a dramatic change in the pharmacological profile with (R)-53 exhibiting a strong affinity for both the dopamine D(2) and serotonin 5-HT(3) receptors, while the corresponding (S)-53 had a potent serotonin 5-HT(3) receptor binding affinity and a moderate dopamine D(2) receptor binding affinity. X-ray crystallographic study of (R)-53 revealed the existence of two energically stable conformers just like two mirror images. This may account for (R)-53 high affinity for both the dopamine D(2) and serotonin 5-HT(3) receptors. Pharmacologically, (R)-53 [AS-8112] showed a potent antagonistic activity for both the dopamine D(2) and serotonin 5-HT(3) receptors in vivo tests and dose-dependently inhibited both the incidence and frequency of emetic episodes induced by cisplatin (ferrets) and morphine (dogs) with ID(50) values of 27.1 microg/kg, po and 136 microg/kg, po, respectively. On the basis of this pharmacological profile, (R)-53 is now under further investigation as a potential broad antiemetic agent.
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Affiliation(s)
- Yoshimi Hirokawa
- Medicinal Chemistry Group, Chemistry Research Laboratories, Dainippon Pharmaceutical Co. Ltd., Enoki 33-94, Suita, Osaka 564-0053, Japan.
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18
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Hirokawa Y, Yamazaki H, Kato S. Synthesis of optically active af-(1-Ethyl-3-methylhexahydro-1,3-diazin-5-yl)- and N-(1-Ethyl-5-methyloctahydro-1,5-diazocin-3-yl)pyridine-3-carboxamides. J Heterocycl Chem 2002. [DOI: 10.1002/jhet.5570390417] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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19
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Hirokawa Y, Horikawa T, Noguchi H, Yamamoto K, Kato S. Process Development of the Synthetic Route to (R)-6-Amino-1-ethyl-4-methylhexahydro-1,4-diazepine. Org Process Res Dev 2002. [DOI: 10.1021/op010068e] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yoshimi Hirokawa
- Discovery Research Laboratories, Dainippon Pharmaceutical Co., Ltd., Enoki 33−94, Suita, Osaka 564-0053, Japan
| | - Tamaki Horikawa
- Discovery Research Laboratories, Dainippon Pharmaceutical Co., Ltd., Enoki 33−94, Suita, Osaka 564-0053, Japan
| | - Hideto Noguchi
- Discovery Research Laboratories, Dainippon Pharmaceutical Co., Ltd., Enoki 33−94, Suita, Osaka 564-0053, Japan
| | - Katsuhisa Yamamoto
- Discovery Research Laboratories, Dainippon Pharmaceutical Co., Ltd., Enoki 33−94, Suita, Osaka 564-0053, Japan
| | - Shiro Kato
- Discovery Research Laboratories, Dainippon Pharmaceutical Co., Ltd., Enoki 33−94, Suita, Osaka 564-0053, Japan
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20
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Horikawa T, Hirokawa Y, Kato S. A practical preparation of methyl 2-methoxy-6-methylaminopyridine-3-carboxylate from 2,6-dichloro-3-trifluoromethylpyridine. Chem Pharm Bull (Tokyo) 2001; 49:1621-7. [PMID: 11767084 DOI: 10.1248/cpb.49.1621] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An effective and practical synthetic route to methyl 2-methoxy-6-methylaminopyridine-3-carboxylate (7), the key intermediate of 5-bromo-2-methoxy-6-methylaminopyridine-3-carboxylic acid (1), from 2,6-dichloro-3-trifluoromethylpyridine (12) was undertaken. Process improvements were highlighted by regioselectivity of 12 with a nitrogen nucleophile and conversion of the 3-trifluoromethyl group into the methoxycarbonyl group. The reaction of 12 with N-benzylmethylamine provided the 6-(N-benzyl-N-methyl)aminopyridine 26a and the regioisomer 26b in >98:<2 ratio in a quantitative yield. Treatment of 2-methoxy-6-methylamino-3-trifluoropyridine (14a) with a large excess of sodium methoxide followed by acid hydrolysis gave the pyridine-3-carboxylic ester 7 in an excellent yield. The potential application of this reaction is also described.
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Affiliation(s)
- T Horikawa
- Chemistry Research Laboratories, Dainippon Pharmaceutical Co., Ltd., Suita, Osaka, Japan
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