- Novel solid-phase preparation of 2,6,9-trisubstituted purines for combinatorial library generation
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A novel procedure for the preparation of 2,6,9-trisubstituted purine libraries has been developed.
- Dorff, Peter H.,Garigipati, Ravi S.
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- Utility of 4,6-dichloro-2-(methylthio)-5-nitropyrimidine. An efficient solid-phase synthesis of olomoucine
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4,6-Dichloro-2-(methylthio)-5-nitropyrimidine has been utilized as a building block for an efficient nine-step synthesis of olomoucine. The methodology reported herein is applicable to the regiocontrolled solution and solid-phase synthesis of libraries of highly substituted purines, as well as other related scaffolds.
- Hammarstr?m, Lars G.J,Smith, David B,Talamás, Francisco X,Labadie, Sharada S,Krauss, Nancy E
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- An efficient direct amination of cyclic amides and cyclic ureas
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An efficient one-step amination of cyclic amides and ureas has been developed. Treatment of cyclic amides and cyclic ureas with BOP in the presence of DBU in various solvents led to the formation of cyclic amidines and cyclic guanidines in good to excellent yields. Concise syntheses of biologically intriguing kinetin and potent kinase inhibitor olomoucin were thus achieved in just one and two steps, respectively.
- Wan, Zhao-Kui,Wacharasindhu, Sumrit,Binnun, Eva,Mansour, Tarek
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- The scope and mechanism of phosphonium-mediated SNAr reactions in heterocyclic amides and ureas
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(Chemical Equation Presented) An efficient "one-step" synthesis of cyclic amidines and guanidines has been developed. Treatment of cyclic amides and ureas with benzotriazol-l-yloxytris(dimethylamino)phosphonium hexafluorophosphate (BOP), base, and nitrogen nucleophiles leads to the formation of the corresponding cyclic amidines and guanidines, typically in good to excellent yields. This method has also been used to prepare heteroaryl ethers and thioethers using phenol and thiophenol nucleophiles. Time course NMR and HPLC-MS studies have facilitated explicit characterization of the proposed intermediates (the phosphonium salt and HOBt adduct); the data reveal a stepwise reaction pathway.
- Wan, Zhao-Kui,Wacharasindhu, Sumrit,Levins, Christopher G.,Lin, Melissa,Tabei, Keiko,Mansour, Tarek S.
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p. 10194 - 10210
(2008/04/12)
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- Synthesis and activity of 2,6,9-trisubstituted purines
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The preparation of a series of 2,6,9-trisubstituted purines and the structure-activity data for the inhibition of cyclin dependent kinase, CDK2 are presented.
- Schow, Steven R.,Mackman, Richard L.,Blum, Cheri L.,Brooks, Eric,Horsma, Amy G.,Joly, Alison,Kerwar, Suresh S.,Lee, Gavin,Shiffman, Dov,Nelson, Marek G.,Wang, Xingbo,Wick, Michael M.,Zhang, Xiaoming,Lum, Robert T.
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p. 2697 - 2702
(2007/10/03)
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- SUBSTITUTED XANTHINES AND CYTOKININ ANALOGUES AS INHIBITORS OF CYTOKININ N-GLUCOSYLATION
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A series of 3-substituted xanthines, 2-(2-hydroxy-2-methylpropylamino)-9-methyl-6-benzylaminopurine and 7-benzylaminooxazolopyrimidine were synthesized as potential inhibitors of cytokinin N-glucosylation.In maize leaf segments the latter compound
- Hocart, Charles H.,Letham, David S.,Parker, Charles W.
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p. 2477 - 2486
(2007/10/02)
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- INHIBITORS OF TWO ENZYMES WHICH METABOLIZE CYTOKININS
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Compounds which inhibit the natural metabolic inactivation of cytokinins are cosiderable physiological significance.In this study, inhibitors have been found for two enzymes which form glucose and alanine conjugates of cytokinin bases, namely, cytokinin 7-glucosyltransferase and β-(9-cytokinin)alanine synthase.The most effective inhibitors found for the former enzyme were the cytokinin analogues 3-methyl-7-n-pentylaminopyrazolopyrimidine, which acted competitively (Ki 22 μM), and the diaminopurine, 6-benzylamino-2-(2-hydroxyethylamino)-9-methylpurine (Ki 3.3 μM).However these compounds were ineffective as inhibitors of the cytokinin-alanine sythase which was inhibited competitively by IAA (Ki 70 μM) and related compounds, especially 5,7-dichloro-IAA (Ki 0.4 μM).Certain urea derivatives were moderately effective inhibitors of the enzymes (Ki ca 100 μM). Key Word Index - Cytokinins; metabolism; cytokinin 7-glucosyltransferase; β-(9-cytokinin)alanine synthase; N6-substituted adenines; auxins; indoleacetic acid.
- Parker, Charles W.,Entsch, Barrie,Letham, David S.
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p. 303 - 310
(2007/10/02)
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