- Preparation method of selective estrogen receptor degradation agent and intermediate thereof
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The invention relates to a benzothiophene-based selective estrogen receptor degradation agent (LSZ-102) and a preparation method of an intermediate thereof t. The preparation method of the LSZ-102 comprises the following steps: a, performing substitution
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Paragraph 0141-0144; 0146
(2020/09/20)
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- Competitive behavior of nitrogen based axial ligands in the oxovanadium(IV)-salen catalyzed sulfoxidation of phenylmercaptoacetic acid
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The sulfoxidation of twelve phenylmercaptoacetic acids (PMAA) by H2O2 catalyzed by three oxovanadium(IV)-salen complexes, having varied substituents on PMAA and salen with regard to their position, size and inductive effect, has been performed spectrophotometrically in 100percent acetonitrile medium. Three nitrogen bases (NB), pyridine (Py), imidazole (ImH) and 1-methylimidazole (MeIm), were used as axial ligands. It has been found that the rate of sulfoxidation is not only tuned by the substituents on PMAA and salen, but it is also varied by the addition of nitrogen bases. The observed order of retardation found among the different nitrogen bases is ImH > MeIm > Py. The rate of reaction decreases with the increase in concentration of the NB axial ligands. The strongly binding ImH shows the least reactivity. Hydroperoxovanadium(V)-salen has been proposed as the sole active oxidizing species. A detailed mechanistic study reveals that the low rate constant values in the presence of the nitrogen base is due to the existence of competition of NB with H2O2 and PMAA during the formation of active species and the coordination of PMAA with active species, respectively. Both electron donating and electron withdrawing substituents on PMAA retard the sulfoxidation rate significantly. The Hammett correlation between the rate constants and substituent constants shows a non-linear concave downward curve which is explained by the existence of two different rate determining steps within the same mechanism; coordination of PMAA with the active species for electron withdrawing substituents and transfer of oxygen to PMAA for electron donating substituents. All the experimental observations are explained by proposing a suitable mechanism.
- Kavitha, C.,Subramaniam, P.
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- Inhibition of monoamine oxidase by 8-phenoxymethylcaffeine derivatives
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A recent study has reported that a series of 8-benzyloxycaffeines are potent and reversible inhibitors of both human monoamine oxidase (MAO) isoforms, MAO-A and -B. In an attempt to discover additional caffeine derivatives with potent MAO inhibitory activities, and to contribute to the known structure-activity relationships of MAO inhibition by caffeine derived compounds, the present study investigates the MAO inhibitory potencies of series of 8-phenoxymethylcaffeine and 8-[(phenylsulfanyl)methyl]caffeine derivatives. The results document that the 8-phenoxymethylcaffeine derivatives act as potent reversible inhibitors of MAO-B, with IC50 values ranging from 0.148 to 5.78 μM. In contrast, the 8-[(phenylsulfanyl)methyl]caffeine derivatives were found to be weak inhibitors of MAO-B, with IC50 values ranging from 4.05 to 124 μM. Neither the 8-phenoxymethylcaffeine nor the 8-[(phenylsulfanyl)methyl]caffeine derivatives exhibited high binding affinities for MAO-A. While less potent than the 8-benzyloxycaffeines as MAO-B inhibitors, this study concludes that 8-phenoxymethylcaffeines may act as useful leads for the design of MAO-B selective inhibitors. Such compounds may find application in the therapy of neurodegenerative disorders such as Parkinson's disease. Using molecular docking experiments, this study also proposes possible binding orientations of selected caffeine derivatives in the active sites of MAO-A and -B.
- Okaecwe, Thokozile,Swanepoel, Abraham J.,Petzer, Anél,Bergh, Jacobus J.,Petzer, Jacobus P.
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experimental part
p. 4336 - 4347
(2012/08/28)
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- Benzothieno[3,2-b]indole derivatives as potent selective estrogen receptor modulators
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A series of estrogen receptor ligands based on benzothieno[3,2-b]indole were synthesized and their binding affinity for estrogen receptor subtypes (ERα and ERβ) and effects on mouse uterus and bone were evaluated. Some of these compounds showed strong bin
- Ji, Qinggang,Gao, Jie,Wang, Junbo,Yang, Chunhao,Hui, Xin,Yan, Xueming,Wu, Xihan,Xie, Yuyuan,Wang, Ming-Wei
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p. 2891 - 2893
(2007/10/03)
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- KINETICS AND MECHANISM OF OXIDATION OF (ARYLTHIO)ACETIC ACIDS BY PYRIDINIUM HYDROBROMIDE PERBROMIDE
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Oxidation of several monosubstituted (phenylthio)acetic acids (PTAA) by pyridinium hydrobromide perbromide (PHPB) was studied in aqueous acetic acid.The reaction is first order with respect to PHPB.Michaelis-Menten type kinetics are observed with respect to (arylthio)acetic acid.The effect of solvent composition indicates that the transition state is more polar than the reactants.The formation constants of the intermediate substrate-PHPB complexes and the rates of their decomposition were determined at different temperatures.The rates of oxidation of para and meta-substituted (phenylthio)acetic acids were correlated with Hammett's substituent constants.The ρ value is -1.60 at 35 deg c.The rates of oxidation of ortho substituted compounds are correlated with Charton's triparametric equation.A mechanism involving the decomposition of the intermediate complex in the slow rate-determining step affording a sulphonium ion which hydrolyses in a subsequent fast step to the sulphoxide is proposed.
- Karunakaran, K.,Elango, K. P.
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p. 429 - 434
(2007/10/02)
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- Photoredox reactions of polypyridyl chromium (III) complexes with arylthioacetic acids in acetonitrile and aqueous media
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The reductive quenching reactions of ,Cr(NN)33+ (NN = 2,2'-bipyridyl, 4,4'-dimethyl-2,2'-bipyridyl and 1,10-phenanthroline) with arylthioacetic acids in acetonitrile and arylthioacetate ions in aqueous media have been studied. The substantial difference in k(q) values between the acetonitrile and aqueous media is traced to the difference in the origin of electron for the reduction of Cr(III) complexes i.e., sulphur in acetonitrile and carboxylate ion in aqueous medium.
- Gnanaraj,Rajagopal,Srinivasan
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p. 9447 - 9456
(2007/10/02)
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- METALATION REACTIONS. VI. STERIC LIMITS IN THE PREPARATION OF 1,2,3-TRI-SUBSTITUTED BENZENE DERIVATIVES
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Metalation of 1,3-dialkoxy-, 1-alkoxy-3-(alkylthio)- and 1,3-bis-(alkylthio)-benzenes with n-butyllithium has been examined to verify the possibility of preparing 1,2,3-tri-substituted benzene derivatives.The reaction is affected by steric hindrance.The yields of the metalation in the position ortho to both the substituents decrease as steric requirement increases becoming zero when the bulk of both the alkyl substituent and the hetero-atom is increased.It has been shown that synthesis of 1,2,3-tri-substituted derivatives by this route is feasible only with small substituents.
- Cabiddu, Salvatore,Maccioni, Antonio,Piras, Pier Paolo,Plumitallo, Antonio
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p. 123 - 128
(2007/10/02)
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