- Evaluation of adenine as scaffold for the development of novel P2X3 receptor antagonists
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Ligands that selectively block P2X3 receptors localized on nociceptive sensory fibres may be useful for the treatment of chronic pain conditions including neuropathic pain, migraine, and inflammatory pain. With the aim at exploring the suitability of aden
- Lambertucci, Catia,Sundukova, Mayya,Kachare, Dhuldeo D.,Panmand, Deepak S.,Dal Ben, Diego,Buccioni, Michela,Marucci, Gabriella,Marchenkova, Anna,Thomas, Ajiroghene,Nistri, Andrea,Cristalli, Gloria,Volpini, Rosaria
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supporting information
p. 41 - 50
(2013/10/01)
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- Method for preparing a benzylic-type ether
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The invention concerns a method for preparing a benzylic-type ether from an aromatic compound. The inventive method for preparing a benzylic-type ether from an aromatic compound is characterised in that it consists in: in a first step, acylating an aromatic compound by reacting said aromatic compound with an acylating agent, in the presence of an efficient amount of zeolite or a Friedel-Crafts catalyst leading to a ketonic compound; in a second step, reducing the carbonyl group into carbinol leading to a benzylic alcohol; in a third step, etherifying the hydroxyl group, by reacting the benzylic alcohol with another alcohol, in the presence of an efficient amount of zeolite.
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- Spectral properties and absolute rate constants for β-scission of ring-substituted cumyloxyl radicals. A laser flash photolysis study
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A laser flash photolysis study of the spectral properties and β-scission reactions of a series of ring-substituted cumyloxyl radicals has been carried out. All cumyloxyl radicals display a broad absorption band in the visible region of the spectrum, which decays on the microsecond time scale, leading to a strong increase in absorption in the UV region of the spectrum, which is attributed to the corresponding acetophenone formed after β-scission of the cumyloxyl radicals. The position of the visible absorption band is red-shifted by the presence of electron-donating ring substituents, while a blue-shift is observed in the presence of electron-withdrawing ring substituents, suggesting that + R ring substituents promote charge separation in the excited cumyloxyl radical through stabilization of the partial positive charge on the aromatic ring of an incipient radical zwitterion. Along this line, an excellent Hammett-type correlation between the experimentally measured energies at the visible absorption maxima of the cumyloxyl radicals and σ+ substituent constants is obtained. A red-shift is also observed on going from MeCN to MeCN/H2O for all cumyloxyl radicals, pointing toward a specific effect of water. The ring substitution does not influence to a significant extent the rate constants for β-scission of the cumyloxyl radicals, which varies between 7.1 × 105 and 1.1 × 106 s-1, a result that suggests that cumyloxyl radical β-scission is not governed by the stability of the resulting acetophenone. Finally, κβ increases on going from MeCN to the more polar MeCN/H2O 1:1 for all cumyloxyl radicals, an observation that reflects the increased stabilization of the transition state for β-scission through increased solvation of the incipient acetophenone product.
- Baciocchi, Enrico,Bietti, Massimo,Salamone, Michela,Steenken, Steen
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p. 2266 - 2270
(2007/10/03)
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- Structural effects on the OH--promoted fragmentation of methoxy-substituted 1-arylalkanol radical cations in aqueous solution: The role of oxygen acidity
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A kinetic and product study of the OH--induced decay in H2O of the radical cations generated from some di- and tri-methoxy-substituted 1-arylalkanols (ArCH(OH)R·+) and 2- and 3-(3,4-dimethoxyphenyl) alkanols has been carried out by using pulse- and γ-radiolysis techniques. In the 1-arylalkanol system, the radical cation 3,4-(MeO)2C6H3CH2OH ·+ decay at a rate more than two orders of magnitude higher than that of its methyl ether; this indicates the key role of the side-chain OH group in the decay process (oxygen acidity). However, quite a large deuterium kinetic isotope effect (3.7) is present for this radical cation compared with its α-dideuterated counterpart. A mechanism is suggested in which a fast OH deprotonation leads to a radical zwitterion which then undergoes a rate-determining 1,2-H shift, coupled to a side-chain-to-ring intramolecular electron transfer (ET) step. This concept also attributes an important role to the energy barrier for this ET, which should depend on the stability of the positive charge in the ring and, hence, on the number and position of methoxy groups. On a similar experimental basis, the same mechanism is suggested for 2,5-(MeO)2C6H3CH2OH ·+ as for 3,4-(MeO)2C6H3CH2OH ·+, in which some contribution from direct C-H deprotonation (carbon acidity) is possible. In fact, the latter process dominates the decay of the trimethoxylated system 2,4,5-(MeO)3C6H2CH2OH ·+, which, accordingly, reacts with OH- at the same rate as that of its methyl ether. Thus, a shift from oxygen to carbon acidity is observed as the positive charge is increasingly stabilized in the ring; this is attributed to a corresponding increase in the energy barrier for the intramolecular ET. When R = tBu, the OH--promoted decay of the radical cation ArCH(OH)R·+ leads to products of C-C bond cleavage. With both Ar = 3,4- and 2,5-dimethoxyphenyl the reactivity is three orders of magnitude higher than that of the corresponding cumyl alcohol radical cations; this suggests a mechanism in which a key role is played by the oxygen acidity as well as by the strength of the scissile C-C bond: a radical zwitterion is formed which undergoes a rate-determining C-C bond cleavage, coupled with the intramolecular ET. Finally, oxygen acidity also determines the reactivity of the radical cations of 2-(3,4-dimethoxyphenyl)ethanol and 3-(3,4-dimethoxyphenyl)propanol. In the former the decay involves C-C bond cleavage, in the latter it leads to 3-(3,4-dimethoxyphenyl) propanal. In both cases no products of C-H deprotonation were observed. Possible mechanisms, again involving the initial formation of a radical zwitterion, are discussed.
- Baciocchi, Enrico,Bietti, Massimo,Gerini, Maria Francesca,Manduchi, Laura,Salamone, Michela,Steenken, Steen
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p. 1408 - 1416
(2007/10/03)
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- 2-SACCHARINYLMETHYL PHOSPHATES, PHOSPHONATES AND PHOSPHINATES USEFUL AS PROTEOLYTIC ENZYME INHIBITORS AND COMPOSITIONS AND METHOD OF USE THEREOF
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4-R 1-R 2-R 3-2-Saccharinylmethyl and 4,7-C-4,5, 6,7-tetrahydro-2-saccharinylmethyl phosphates, phosphonates and phosphinates of formulas I and IIA respectively herein, useful in the treatment of degenerative diseases, and compositions containing them, methods for using them to treat degenerative diseases, and processes for their preparation by reaction of the corresponding 2-halomethylsaccharins with a phosphate, phosphonate or phosphinic acid of formula III herein in the presence of an acid-acceptor.
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- 2-SACCHARINYLMETHYL AND 4,5,6,7-TETRAHYDRO-2-SACCHARINYLMETHYL PHOSPHATES, PHOSPHONATES AND PHOSPHINATES USEFUL AS PROTEOLYTIC ENZYME INHIBITORS AND COMPOSITIONS AND METHOD OF USE THEREOF
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4-R 1-R 2-R 3-2-Saccharinylmethyl, 4-R 4-4-R 5-6-R 6-4,5,6,7-tetrahydro-2-saccharinylmethyl and 4,7-C-4,5, 6,7-tetrahydro-2-saccharinylmethyl phosphates, phosphonates and phosphinates of formulas I, II and IIA respectively herein, useful in the treatment of degenerative diseases, and compositions containing them, methods for using them to treat degenerative diseases, and processes for their preparation by reaction of the corresponding 2-halomethylsaccharins with a phosphate, phosphonate or phosphinic acid of formula III herein in the presence of an acid-acceptor.
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- Antiestrogens. Synthesis and Evaluation of Mammary Tumor Inhibiting Activity of 1,1,2,2-Tetraalkyl-1,2-diphenylethanes
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Among the newly synthesized 1,1,2,2-tetraalkyl-1,2-diphenylethanes, 1,1,2,2-tetramethyl-1,2-bis(4'-hydroxyphenyl)ethane (23) and 1,1,2,2-tetramethyl-1,2-bis(3'-hydroxyphenyl)ethane (26) were the most active compounds regarding estradiol receptor affinity, exhibiting Ka values of 0.73*108 and 0.67*108 M-1, respectively.In vivo, 23 and 26 showed only very small uterotrophic activity in the mouse.They strongly inhibited (73percent) the estrone-stimulated mouse uterine growth.Tested on the 9,10-dimethyl-1,2-benzanthracene induced hormone-dependent mammary adenocarcinoma of the Sprague-Dawley rat, compounds 23 and 26 exhibited a dose-dependent inhibition of the tumor growth, having a strong effect at a dose of 20 (mg/kg)/day (compound 23).
- Hartmann, Rolf W.,Kranzfelder, Gerhard,Angerer, Erwin, v.,Schoenenberger, Helmut
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p. 841 - 848
(2007/10/02)
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