- Mechanosynthesis of N-methyl imines using recyclable imidazole-based acid-scavenger: In situ formed ionic liquid as catalyst and dehydrating agent
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1,1′-(1,4-Butanediyl)bis(imidazole) was prepared by a modified method and its application as an efficient promoter was demonstrated for the mechanosynthesis of N-methyl imines using ball milling as a non-conventional process under solvent-free conditions. In this new protocol design, the bis-imidazole acted as a recyclable acid-scavenging agent. This efficient approach to the N-methyl imines displays a combination of the synthetic virtues of a non-conventional condensation reaction with ecological benefits and convenience of a facile mechanosynthetic process. The current method has advantages such as reduced waste by avoiding solvent, exclusion of hazardous materials during the reaction, elimination of handling an anhydrous gas in an evacuated container or a solution of methylamine in ethanol, good yields for relatively unreactive benzaldehydes containing electron-donating substituents, short reaction times, and metal- and acid-free conditions. Furthermore, the promoter was easily regenerated and reused several times with no significant loss of activity.
- Khaligh, Nader Ghaffari,Ling, Ong Chiu,Mihankhah, Taraneh,Johan, Mohd Rafie,Ching, Juan Joon
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p. 194 - 199
(2018/12/04)
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- Method for synthesizing imine by catalytic oxidation of asymmetric secondary amine in presence of visible light
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The invention belongs to the technical field of chemical engineering and pharmaceutical industry, and particularly relates to a method for synthesizing imine by catalytic oxidation of asymmetric secondary amine in the presence of visible light. With aza-metalloporphyrin containing sulfur as a visible light catalyst, 1,8-diazabicycloundecene-7-alkene as an auxiliary agent, and oxygen as an oxidant,asymmetric secondary amine is subjected to catalytic oxidation under irradiation of visible light of lambda being larger than or equal to 420nm, so as to obtain the oxidation product imine. A new andefficient imine production way is provided.
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Paragraph 0025-0026; 0060-0064
(2018/11/22)
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- A telescopic one-pot synthesis of β-lactam rings using amines as a convenient source of imines
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A facile synthetic approach to substituted β-lactams was designed, using secondary benzylic amines and acid chlorides as starting materials. The reactions proceeded smoothly and all the products were obtained in good yields.
- Rajam?ki, Suvi H. M.,De Luca, Lidia,Capitta, Francesca,Porcheddu, Andrea
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p. 38553 - 38557
(2016/06/01)
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- Synthesis and biological evaluation of urea derivatives as highly potent and selective rho kinase inhibitors
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RhoA and its downstream effector ROCK mediate stress fiber formation and cell contraction through their effects on the phosphorylation of myosin light chain (MLC). Inhibition of the RhoA/ROCK pathway has proven to be a promising strategy for several indications such as cardiovascular disease, glaucoma, and inflammatory disease. In 2010, our group reported urea-based ROCK inhibitors as potential antiglaucoma agents. These compounds showed potent IC50 values in enzymatic and cell-based assays and significant intraocular pressure (IOP)-lowering effects in rats (~7 mmHg).(22) To develop more advanced ROCK inhibitors targeting various potential applications (such as myocardial infarction, erectile dysfunction, multiple sclerosis, etc.) in addition to glaucoma, a thorough SAR for this urea-based scaffold was studied. The detailed optimization process, counter-screening, and in vitro and in vivo DMPK studies are discussed. Potent and selective ROCK inhibitors with various in vivo pharmacokinetic properties were discovered.
- Yin, Yan,Lin, Li,Ruiz, Claudia,Khan, Susan,Cameron, Michael D.,Grant, Wayne,Pocas, Jennifer,Eid, Nibal,Park, Hajeung,Schr?ter, Thomas,Lograsso, Philip V.,Feng, Yangbo
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supporting information
p. 3568 - 3581
(2013/06/27)
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- Simple and efficient one-pot solvent-free synthesis of N-methyl imines of aromatic aldehydes
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A one-pot solvent-free synthesis of N-methyl imines in good to excellent yields was performed by grinding together aromatic aldehydes and methylamine hydrochloride in the presence of a base. The best yields were achieved when an excess of methylamine hydrochloride and inexpensive sodium hydrogen carbonate was used (usually in a molar ratio ArCHO/CH3NH2· HCl/NaHCO3 = 1:5:5), allowing the reaction to proceed for 1 h (in the case of aromatic aldehydes containing electron-withdrawing substituents) or overnight (in the case of electron-rich aldehydes). After a simple work-up (extraction with diethyl ether) the obtained products were mostly pure enough for spectral characterization. In this way, 31 N-methyl imines were prepared, among which eight were synthesized for the first time. Their structures were elucidated by spectral means (1H- and 13C-NMR, IR, MS) whenever it was possible. In the case of salicylaldehyde and 4-chlorobenzaldehyde, the synthesis of the corresponding imines was also conducted on a gram-scale with a 72% and 84% isolated yield, respectively. The present approach not only provides good to high yields, but also eliminates the disadvantages of the traditional synthesis of N-methyl imines, such as the use of hazardous solvents and more or less expensive catalysts and the necessity of work/handling with an anhydrous gas in pressurized containers.
- Radulovi?, Niko S.,Miltojevi?, Ana B.,Vuki?evi?, Rastko D.
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p. 257 - 270
(2013/05/09)
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- 4-Phenyl tetrahydroisoquinolines as dual norepinephrine and dopamine reuptake inhibitors
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Novel 4-phenyl tetrahydroisoquinolines that inhibit both dopamine and norepinephrine transporters were designed and prepared. In this Letter, we describe the synthesis, in vitro activity and associated structure-activity relationships of this series. We also report the ex vivo NET occupancy of a representative compound, 41.
- Pechulis, Anthony D.,Beck, James P.,Curry, Matt A.,Wolf, Mark A.,Harms, Arthur E.,Xi, Ning,Opalka, Chet,Sweet, Mark P.,Yang, Zhicai,Vellekoop, A. Samuel,Klos, Andrew M.,Crocker, Peter J.,Hassler, Carla,Laws, Mia,Kitchen, Douglas B.,Smith, Mark A.,Olson, Richard E.,Liu, Shuang,Molino, Bruce F.
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p. 7219 - 7222
(2013/01/15)
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- Highly enantioselective synthesis of tetrahydroquinolines via cobalt(II)-catalyzed tandem 1,5-hydride transfer/cyclization
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A chiral catalyst prepared from N,N′-dioxide and Co(BF 4)2·6H2O was applied in the asymmetric hydride transfer initiated cyclization reaction, giving optically active tetrahydroquinolines in good yields with high enantioselectivities under mild reaction conditions. Meanwhile, in light of the absolute configuration of the product, a possible working model was proposed to explain the origin of the activation and asymmetric induction.
- Cao, Weidi,Liu, Xiaohua,Wang, Wentao,Lin, Lili,Feng, Xiaoming
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supporting information; scheme or table
p. 600 - 603
(2011/04/15)
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- Efficient synthesis of new 4-arylideneimidazolin-5-ones related to the GFP chromophore by 2+3 cyclocondensation of arylideneimines with imidate ylides
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A 2+3 condensation of a wide assortment of Schiff bases, prepared from aromatic aldehydes and primary amines, with methyl (1-ethoxyethylideneamino) acetate allows convenient access to an extensive family of substituted 4-arylideneimidazolin-5-one analogues of the green fluorescent protein (GFP) chromophore. Georg Thieme Verlag Stuttgart · New York.
- Baldridge, Anthony,Kowalik, Janusz,Tolbert, Laren M.
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scheme or table
p. 2424 - 2436
(2010/09/06)
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- Gamma-lactams-A novel scaffold for highly potent and selective α7 nicotinic acetylcholine receptor agonists
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A novel class of α7 nicotinic acetylcholine receptor (nAChR) agonists has been discovered through high-throughput screening. The cis γ-lactam scaffold has been optimized to reveal highly potent and selective α7 nAChR agonists with in vitro activity and selectivity and with good brain penetration in mice.
- Enz, Albert,Feuerbach, Dominik,Frederiksen, Mathias U.,Gentsch, Conrad,Hurth, Konstanze,Mueller, Werner,Nozulak, Joachim,Roy, Bernard L.
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scheme or table
p. 1287 - 1291
(2009/10/02)
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- A novel construction of 2-benzazepine scaffold based on TiCl 4-mediated tandem Mannich reaction - Aromatic electrophilic substitution
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A novel construction of 2-benzazepine derivatives based on TiCl 4-mediated tandem Mannich reaction of electron-rich benzyl iminium ions with alkenyl ethers and Friedel - Crafts-type alkylation is described. The protocol is amenable to provide the tricyclic furo[3,2-d][2]benzazepine and pyrano[3,2-d][2]benzazepine derivatives, respectively, with 2,3-dihydrofuran or 3,4-dihydro-2H-pyran as the substrates.
- Li, Liangxi,Li, Zhiming,Wang, Quanrui
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experimental part
p. 2754 - 2761
(2010/04/02)
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- Cholinesterase inhibitors: SAR and enzyme inhibitory activity of 3-[ω-(benzylmethylamino)alkoxy]xanthen-9-ones
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In this work, we further investigated a previously introduced class of cholinesterase inhibitors. The removal of the carbamic function from the lead compound xanthostigmine led to a reversible cholinesterase inhibitors 3. Some new 3-[ω-(benzylmethylamino)alkoxy]xanthen-9-one analogs were designed, synthesized, and evaluated for their inhibitory activity against both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). The length of the alkoxy chain of compound 3 was increased and different substituents were introduced. From the IC50 values, it clearly appears that the carbamic residue is crucial to obtain highly potent AChE inhibitors. On the other hand, peculiarity of these compounds is the high selectivity toward BuChE with respect to AChE, being compound 12 the most selective one (6000-fold). The development of selective BuChE inhibitors may be of great interest to clarify the physiological role of this enzyme and to provide novel therapeutics for various diseases.
- Piazzi, Lorna,Belluti, Federica,Bisi, Alessandra,Gobbi, Silvia,Rizzo, Stefano,Bartolini, Manuela,Andrisano, Vincenza,Recanatini, Maurizio,Rampa, Angela
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p. 575 - 585
(2008/03/12)
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- ACTIVATING ACTION OF THE IMMONIUM GROUP IN THE SUBSTITUTION OF ALKOXYL AND HALOGEN ATOMS BY THE ALKYLAMINO GROUP IN THE BENZENE RING
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The substitution of the alkoxy group in o-, p-, and m-alkoxybenzylidenedimethylimmonium iodides by the action of aliphatic amines was investigated.Only p-alkoxy derivatives enter into the reaction forming, after hydrolysis, p-alkyl- and p-dialkylaminobenzaldehydes.Substitution can also be realized in p-alkoxybenzaldehydes and Schiff bases in the presence of the amine hydrochloride.Similarly, the halogen atom in p-halogenobenzaldehydes is substituted by the aliphatic amine residue.Quantum-mechanical calculations of the energy of anionic localization and charge at the attacked carbon atom o f the benzene ring are consistent with the experimantal data.
- Yudin, L. G.,Blokhin, A. V.,Bundel', Yu. G.,Simkin, B. Ya.,Terenin, V. I.
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p. 2064 - 2068
(2007/10/02)
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