- Preparation methods of aprepitant impurity
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The invention discloses preparation methods of an aprepitant impurity, which comprise isomer impurity synthesis method of six aprepitant key intermediates (2R, 3S)-2-[(1R)-1-[3, 5-bis (trifluoromethyl)-phenyl] ethoxy]-3-(4-fluorophenyl) morpholine, respectively, synthesis of four diastereomer impurities, synthesis of one enantiomer impurity and synthesis of one by-product impurity. The methods have the beneficial effects that the five synthesis methods are simple and feasible, the raw materials are easy to obtain, the conditions are mild, the cost is low, the production is facilitated, and meanwhile, the isomer impurities of the synthesized aprepitant key intermediate provide a new intermediate raw material for the preparation of aprepitant.
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Paragraph 0105-0106
(2020/07/13)
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- IrIII-Catalyzed direct syntheses of amides and esters using nitriles as acid equivalents: A photochemical pathway
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An unprecedented IrIII[df(CF3)ppy]2(dtbbpy)PF6-catalyzed simple photochemical process for direct addition of amines and alcohols to the relatively less reactive nitrile triple bond is described herein. Various amides and esters are synthesized as the reaction products, with nitriles being the acid equivalents. A mini-library of different types of amides and esters is made using this mild and efficient process, which uses only 1 mol% of photocatalyst under visible light irradiation (λ = 445 nm). The reaction strategy is also efficient for gram-scale synthesis.
- Talukdar, Ranadeep
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supporting information
p. 5303 - 5308
(2020/04/17)
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- A study on reactions of an alkynylsilane with oxone-KX (X = Cl, Br, I) and its one-pot transformation into an amide/ester
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Oxyhalogenation reactions of a variety of alkynylsilanes were studied using oxone as mild oxidant and KCl, KBr, and KI as halogen sources. In this study, reaction of an alkynylsilane with oxone-KX (X = Cl or Br) produced trichloromethyl/tribromomethyl ketones inhigh yields. Under similar conditions, however, reactions of alkynylsilanes with oxone-KI were found to give exclusively 1,2,2-triiodovinyl derivatives in high yields. In this study, new methods were deveoped for effcient one-pot tranformation of alkynylsilanes into amides and esters by reaction with amines and alcohols respectively via trihalomethyl ketone.
- Sriramoju, Vinodkumar,Jillella, Raveendra,Kurva, Srinivas,Madabhushi, Sridhar
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p. 560 - 562
(2017/03/30)
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- Synthesis and antibacterial activity of 3-benzylamide derivatives as FtsZ inhibitors
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The emergence and spread of multidrug-resistant strains of the human pathological bacteria are generating a threat to public health worldwide. In the current study, a series of PC190723 derivatives was synthesized and investigated for their antimicrobial activity. The compounds exhibited good activity against several Gram-positive bacteria as determined by comparison of diameters of the zone of inhibition of test compounds and standard antibiotics. Compound 9 with a fluorine substitution on the phenyl ring showed the best antibacterial activity in the series against M. smegmatis with the zone ratio of 0.62, and against S. aureus with the zone ratio of 0.44. The results from this study indicate that based on the unique 3-methoxybenzamide pharmacophore, compound 9 may represent a promising lead candidate against Gram-positive bacteria that are worthy of further investigation
- Hu, Zhongping,Zhang, Shasha,Zhou, Weicheng,Ma, Xiang,Xiang, Guangya
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supporting information
p. 1854 - 1858
(2017/04/04)
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- Copper-catalyzed Csp3-O cross-coupling of unactivated alkyl halides with organic peroxides
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An efficient Cu-catalyzed Csp3-O coupling of peroxides with haloalkanes is described. High yields of products were achieved under mild conditions. Significantly, in addition to primary alkyl halides, secondary alkyl halogenated hydrocarbons could also be applied to this system. The new reaction system could tolerate a wide range of organic peroxides.
- Chen, Huan-Huan,Wang, Guang-Zu,Han, Jin,Xu, Meng-Yu,Zhao, Yong-Qiang,Xu, Hua-Jian
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p. 212 - 217
(2014/01/06)
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- Cu-catalyzed esterification reaction via aerobic oxygenation and C-C bond cleavage: An approach to α-ketoesters
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The Cu-catalyzed novel aerobic oxidative esterification reaction of 1,3-diones for the synthesis of α-ketoesters has been developed. This method combines C-C σ-bond cleavage, dioxygen activation and oxidative C-H bond functionalization, as well as provides a practical, neutral, and mild synthetic approach to α-ketoesters which are important units in many biologically active compounds and useful precursors in a variety of functional group transformations. A plausible radical process is proposed on the basis of mechanistic studies.
- Zhang, Chun,Feng, Peng,Jiao, Ning
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supporting information
p. 15257 - 15262
(2013/11/06)
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- Triphenylphosphine dibromide: a simple one-pot esterification reagent
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We report a one-pot, expedient protocol for the conversion of carboxylic acids to their esters using excess triphenylphosphine dibromide, base, and the alcohol. The reaction gave the esterified product in moderate-to-high yields (30-95%). For chiral acids, the reaction proceeded with little or no racemization. Use of a chiral alcohol in this transformation gave the ester with retention of configuration of the stereogenic center. Information is presented indicating that esterification proceeds through the intermediate generation of an acyloxyalkoxyphosphorane and where steric interactions play an important role in the energetics of the reaction.
- Salomé, Christophe,Kohn, Harold
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supporting information; experimental part
p. 456 - 460
(2009/04/06)
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- RADIOHALOTHYMIDINES AND METHODS OF THEIR SYNTHESIS AND USE IN PET IMAGING OF CANCERS
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We disclose methods of synthesizing radiohalidated organic compounds and their use in positron emission tomography (PET) imaging of cancer cells. We also disclose specific N3 -radiohaloalkyl thymidines and salts thereof.
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Page/Page column 10
(2008/06/13)
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- An alternative oxidising and brominating method converting alcohols to aldehydes and β-bromoethyl esters using ionic liquid [Bmim][Br3]
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[Bmim][Br3] is an oxidising reagent which converts alcohols into aldehydes and ketones in mild conditions and good yields; the use of the ionic liquid (IL) as both an oxidising and a brominating reagent in the one-pot synthesis of β-bromoethyl esters from benzyl alcohols and diols has also been studied.
- Zhang, Yu,Bao, Weiliang
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p. 263 - 266
(2007/10/03)
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- One-pot synthesis of ω-bromoesters from aromatic aldehydes and diols using pyridinium hydrobromide perbromide
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A simple and efficient one-pot procedure has been developed for the synthesis of ω-bromoesters from aromatic aldehydes and diols in the presence of pyridinium hydrobromide perbromide (PHPB) and triethoxymethane in which aldehyde reacts first with diol and the product, cyclic acetal, reacts with PHPB to give the final product, ω-bromoesters.
- Aoyama, Tadashi,Takido, Toshio,Kodomari, Mitsuo
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p. 1989 - 1992
(2007/10/03)
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- LEVODOPA PRODRUGS, AND COMPOSITIONS AND USES THEREOF
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Prodrugs of levodopa, methods of making prodrugs of levodopa, methods of using prodrugs of levodopa, and compositions of prodrugs of levodopa are disclosed. Wherein Q is selected from X-CO-, and -CO-X-; X is selected from-O-, and -NR6-; n is an
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Page/Page column 43
(2008/06/13)
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- Kinetic stabilization of an oligomeric protein by a single ligand binding event
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Protein native state stabilization imposed by small molecule binding is an attractive strategy to prevent the misfolding and misassembly processes associated with amyloid diseases. Transthyretin (TTR) amyloidogenesis requires rate-limiting tetramer dissociation before misassembly of a partially denatured monomer ensues. Selective stabilization of the native TTR tetramer over the dissociative transition state by small molecule binding to both thyroxine binding sites raises the kinetic barrier of tetramer dissociation, preventing amyloidogenesis. Assessing the amyloidogenicity of a TTR tetramer having only one amyloidogenesis inhibitor (I) bound is challenging because the two small molecule binding constants are generally not distinct enough to allow for the exclusive formation of TTR·I in solution to the exclusion of TTR·I2 and unliganded TTR. Herein, we report a method to tether one fibril formation inhibitor to TTR by disulfide bond formation. Occupancy of only one of the two thyroxine binding sites is sufficient to inhibit tetramer dissociation in 6.0 M urea and amyloidogenesis under acidic conditions by imposing kinetic stabilization on the entire tetramer. The sufficiency of single occupancy for stabilizing the native state of TTR provides the incentive to search for compounds displaying striking negative binding cooperativity (e.g., Kd1 in nanomolar range and Kd2 in the micromolar to millimolar range), enabling lower doses of inhibitor to be employed in the clinic, mitigating potential side effects.
- Wiseman, R. Luke,Johnson, Steven M.,Kelker, Matthew S.,Foss, Ted,Wilson, Ian A.,Kelly, Jeffery W.
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p. 5540 - 5551
(2007/10/03)
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- One-pot synthesis of aryl sulfones from alcohols
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A one-pot synthesis of aryl sulfones from primary alcohols is described. Alcohols were treated with N-bromosuccinimide and triphenylphosphine, followed by addition of sodium arenesulfinate with a catalytic amount of tetrabutylammonium iodide to afford the aryl sulfones in good to high yields.
- Murakami, Teiichi,Furusawa, Kiyotaka
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p. 479 - 482
(2007/10/03)
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- A new synthetic method for haloalkyl carboxylic esters from the radical ring cleavage of cyclic acetals with haloform
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A one-pot reaction of cyclic acetals with haloform catalyzed by AIBN(2,2'-azobisisobutyronitrile) provides a novel convenient way to prepare directly haloalkyl carboxylic esters in good yields.
- Hai-Xia, Lin,Liang-Heng, Xu,Nai-Ju, Huang
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p. 303 - 306
(2007/10/03)
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- Ester-containing quaternary ammonium salts as adhesion improving toner charge agents
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Toner particles comprising a polyester binder and a charge control agent are provided wherein such agent is a quaternary ammonium salt having one or more ester-containing moieties. Such an ester-containing salt causes toner particles to display lower fusing temperature, improved paper adhesion indexes, and improved polyester binder compatibility compared to nonesterified salts.
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- Ester-containing quaternary pyridinium salts
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New ester-containing quaternary pyridinium salts are provided having advantageous utility as charge control agents in electrostatographic toners and developers. The salts have the structure: STR1 wherein R 1 is alkyl or aryl, X is --CH 2 -- n, Y is hydrog
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- REACTION DU N-BROMOSUCCINIMIDE SUR LES ARYL-2 DIOXOLANNES-1,3 DEROULEMENT DE LA REACTION
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Reaction of NBS with 1,3-dioxolanes fused to a bicyclo skeleton involves two intermediates, the dioxolanylium ion and the 2-succinimido-1,3-dioxolane.Evidence is presented that the unusual stability of the former ionic species is due to the steric
- Bazbouz, Akram,Christol, Henri,Coste, Jacques,Plenat, Francoise
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p. 1955 - 1960
(2007/10/02)
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