- Cyclization of 2-(3-halopropyloxy)phenoxide ions in functionalized surfactants
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Observed rate constants (k(obs)) of cyclization of 2-(3-halopropyloxy)phenoxide (halo = bromo, iodo; PhBr7 and PhI7, respectively) in aqueous micelles of N-hexadecyl-N-(2-hydroxyethyl)-N,N-dimethylammonium bromide (1) depend on [1] and [NaOH]. The rate profiles go through a maximum and, at high [1], the catalytic effect is modest. By contrast, k(obs) in aqueous micelles of N-hexadecyl-N-(2-hydroxyethyl)-N,N-dimethylammonium sulfate (2) increases monotonically with increasing surfactant concentration and becomes constant at high [2]. 1H, 13C, and 14N NMR spectra of 1 and 2 show that micelles of 1 and 2 do not differ in dimension and shape and that the average conformations of 1 and 2 are similar.
- Cerichelli, Giorgio,Luchetti, Luciana,Mancini, Giovanna,Savelli, Gianfranco
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Read Online
- Quinoxaline compound, preparation method and application of quinoxaline compound in medicine
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The invention provides a quinoxaline compound, a preparation method and application of the quinoxaline compound in medicine, and particularly relates to a quinoxaline compound with PAR4 antagonistic activity, a preparation method of the quinoxaline compound, a pharmaceutical composition containing the quinoxaline compound and application of the quinoxaline compound. Specifically, the invention provides a compound shown as a general formula I and/or II or a tautomer or pharmaceutically acceptable salt thereof, a preparation method of the compound, and application of the compound or the tautomer or the pharmaceutically acceptable salt in medicines for preventing and/or treating thromboembolic diseases.
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Paragraph 0310-0313
(2021/07/24)
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- AN IMPROVED METHOD FOR THE PREPARATION OF ALKYLENEDIOXYBENZENE COMPOUNDS
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This invention relates to an improved method for preparing alkylenedioxybenzene compounds of Formula I, from the corresponding ortho-dihydroxy aromatic compound of Formula II wherein n is 0, 1, 2 or 3; and R1 and R2 independently represent H, linear or branched C1 – C10 alkyl or alkenyl group, cycloalkyl group, halogen selected from C1, Br, I, nitro (-NO2), alkoxy (-OR) or SR thioether (-SR), wherein R is linear or branched alkyl group comprising C1-C6 carbon atoms.
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Page/Page column 14; 15
(2017/10/13)
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- An efficient strategy for protecting dihydroxyl groups of catechols
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A novel strategy for protecting dihydroxyl groups of catechols has been developed. Base-mediated cyclizations of catechols with 1,3-dibromopropane provided the corresponding benzo[b]1,4-dioxepans, and herefrom the protecting group was easily cleaved by aluminum chloride. The preparation of the antibacterial and antifungal agent 4-(2-aminothiazol-4-yl)benzene-1,2-diol from catechol reliably verified its availability amenable to various harsh reaction conditions. Georg Thieme Verlag Stuttgart - New York.
- Huang, Wei-Bin,Guo, Ying,Jiang, Jian-An,Pan, Xian-Dao,Liao, Dao-Hua,Ji, Ya-Fei
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supporting information
p. 741 - 746
(2013/05/09)
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- Multicyclic sulfonamide compounds as inhibitors of histone deacetylase for the treatment of disease
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Disclosed herein are sulfonamide compounds of Formula VII as described herein. Methods and compositions are disclosed for treating disease states including, but not limited to cancers, autoimmune diseases, tissue damage, central nervous system disorders, neurodegenerative disorders, fibrosis, bone disorders, polyglutamine-repeat disorders, anemias, thalassemias, inflammatory conditions, cardiovascular conditions, and disorders in which angiogenesis play a role in pathogenesis, using the compounds of the invention. In addition, methods of modulating the activity of histone deacetylase (HDAC) are also disclosed.
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Page/Page column 17; 24
(2010/11/25)
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- Quaternary ammonium salt-assisted organic reactions in water: Alkylation of phenols
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A series of quaternary ammonium salts has been tested as phase transfer agents to promote reactions between phenols and alkyl halides in an aqueous solution of sodium hydroxide in the absence of organic solvent. Methyltrioctylammonium chloride emerges as the most effective catalyst.
- Eynde,Mailleux
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- Cyclisation and decarboxylation in zwitterionic micelles: effects of head group structure
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The spontaneous decrboxylation of 6-nitrobenzisoxazole-3-carboxylate ion is strongly catalysed by micelles of zwitterionic surfactants, viz., sulfobetaines +R2(CH2)3SO3-, R = Me, Pr and C16H33N+Me2(CH2)3SO3-> and amine oxides (C14H29N+R2O-, R =Me,Pr), with rates enhanced by factors of up to 1800.These micelles and those of the corresponding carboxybetaines are more effective catalysts than those of the corresponding cationic surfactants.In all cases a change from Me to Pr at the head group speeds reaction by factors of ca. 5-8 for the sulfobetaines and amine oxides and ca. 14 for the cationic surfactants.Cyclizations of the o-3-halopropyloxyphenoxide ions (halogen = Br,I), which are intramolecular SN2 reactions, are modestly micellar catalysed, but structural effects on the micellar catalysis by cationic and betaine surfactants are in the same sequence, as for decarboxylation.
- Profio, Pietro Di,Germani, Raimondo,Savelli, Gianfranco,Cerichelli, Giorgio,Spreti, Nicoletta,Bunton, Clifford A.
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p. 1505 - 1510
(2007/10/03)
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- Solvent and micellar effects upon the cyclisation of o-3-halopropyloxyphenoxyde
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Rates of intramolecular cyclisations of o-(3-halopropyloxy)phenoxide ion increase with decreasing solvent polarity in the order H2O iOH I/kBr indicate the relative importance of these interactions.Micelles of CTAX increase the rates by factors of ca. 2 for (1a) and by 4 for (1b), with little effect by the counter-ion.Rate enhancements and kI/kBr increase sharply in the sequence of surfactant head groups N+Me3 +Et3 +Pr3 +Bu3.Increasing the size of the n-alkyl group apparently decreases hydration of the aryloxide without destabilising the transition state.These micellar medium effects can be related to medium effects in intermolecular reactions in micelles.
- Cerichelli, Giorgio,Luchetti, Luciana,Mancini, Giovanna,Muzzioli, Maria Novella,Germani, Raimondo,et al.
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p. 1081 - 1086
(2007/10/02)
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- Structure and Reactivity of Lithium and Sodium Aryloxides in Dimethylformamide. Ions, Ion Pairs, and Ion Triplets
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Reactivity and u.v. spectra of aryloxide ions in dimethylformamide are affected by the addition of either Li(1+) and Na(1+) ions in a way that suggests the occurrence of ion triplets M(1+)A(1-)M(1+) in addition to free ions and ion pairs.
- Crescenzi, Manuela,Galli, Carlo,Mandolini, Luigi
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p. 551 - 553
(2007/10/02)
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- Imidazole derivatives
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Tricyclic imidazole derivatives of the formula STR1 wherein R1 is 2-pyridyl optionally substituted by lower alkyl or lower alkoxy, n is the integer 0 or 1, R2 is hydrogen or lower alkyl, R3 and R4, independently, are hydrogen or lower alkyl, A is a group of the formula STR2 m is the integer 2 or 3, R5, R6, R7 and R8, independently, are hydrogen or lower alkyl, and R9 is hydrogen and R10 is hydrogen or lower alkyl or R9 and R10 taken together are oxo, provided that at least one of R3 and R4 is lower alkyl when A is a group of the formula and their pharmaceutically acceptable acid addition salts. The compounds of formula I inhibit gastric acid secretion and prevent the formation of gastric ulcers.
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- Ring-Closure Reactions. 21. Intramolecular β-Elimination Competing with Ring Formation from o-(ω-Bromoalkoxy)phenoxides over a Wide Range of Ring Sizes
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Unimolecular β-elimination of HBr from the CH2CH2Br end of o--OC6H4O(CH2)n-4Br has been interpreted as an E2-type reaction promoted by the distal phenoxide group acting as a base.Combination of careful product analyses with kinetic data has provided rate constants and effective molarities for intramolecularly assisted elimination reactions occurring through 7-, 8-, 9-, 10-, and 14-membered ring transition states.A comparison is carried out with the competing intramolecular substitution reactions leading to ring formation.Attention is called to the specific entropic and geometrical requirements of intramolecular elimination in which the donor-proton-acceptor arrangement is a part of a cyclic structure.The importance of the present results in the general field of intramolecular acid or base catalysis phenomena is discussed.
- Cort, Antonella Dalla,Mandolini, Luigi,Masci, Bernardo
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p. 3979 - 3982
(2007/10/02)
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- Conformational dynamic investigation of 1,5-benzodiazepin and its dimethyl derivative by 1H and 13C nmr
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The conformational and dynamic properties of 1,5-dioxa-6,7-benzocycloheptene (2; 1,5-benzodiazepin) and its dimethyl derivative (7) have been investigated by dinamic 1H and 13C nmr methods.Analysis of the spectra at low temperatures (below coalescence) indicates that the most stable seven-membered ring conformations detected for solutions in CHF2Cl are a mixture of the chair (C, 80percent) and the twist-boat (TB, 20percent) for 2 and a mixture of TB (64percent) and C (36percent) for 7.Free energy barriers were determined for the chair inversion of 2 (6.5 kcal/mol) and 7 (7.5 kcal/mol) as well as for the twist-boat pseudorotation of 7 (6.8 kcal/mol).The conformational properties of these seven-membered heterocycles are discussed and compared to those known for 2,4-benzodiazepins.
- Menard, D.,St-Jacques, M.
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p. 1160 - 1168
(2007/10/02)
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- Ring-closure Reactions. Part 15. Solvent Effect on Cyclic Aralkyl Ether Formation by Intramolecular Williamson Synthesis
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Product analysis, rate data, and effective molarity (e.m.) values have been obtained for the formation of catechol polymethylene ethers by the intramolecular alkylation of o-ω-bromoalkoxyphenoxides in Me2SO-water (99:1,v/v).Twelve ring sizes were investigated in the range 6-32.Comparison with similar data for the reaction in EtOH-water (75:25,v/v) (except for n 32) showed the e.m. values are largely independent of solvent despite the large solvent effect observed in both the cyclization reaction and the related intermolecular model reaction.Small effects only were observed in the medium ring region.The main possible factors playing a role in solvent effects on intramolecular cyclization have been critically analysed in the light of data.
- Cort, Antonella Dalla,Illuminati, Gabriello,Mandolini, Luigi,Masci, Bernardo
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p. 1774 - 1777
(2007/10/02)
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