- Synthesis of N-carbobenzoxy-N,N-acetals
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A series of N-carbobenzoxy-N,N-acetals have been synthesized by the reaction of aromatic aldehydes or certain aliphatic aldehydes with benzyl carbamate and morpholine. The N,N-acetals can be converted into N-carbobenzoxy-N,S-acetals with benzyl thiol.
- Ding,Silverman
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Read Online
- Indium(III)-Catalyzed Synthesis of Primary Carbamates and N-Substituted Ureas
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An indium triflate-catalyzed synthesis of primary carbamates from alcohols and urea as an ecofriendly carbonyl source has been developed. Various linear, branched, and cyclic alcohols were converted into the corresponding carbamates in good to excellent yields. This method also provided access to N-substituted ureas by carbamoylation of amines. All the products were obtained by simple filtration or crystallization, without the need for chromatographic purification. Mechanistic investigations suggest that the carbamoylation reaction proceeds through activation of urea by O-coordination with indium, followed by nucleophilic attack by the alcohol or amine on the carbonyl center of urea. The inexpensive and easily available starting materials and catalyst, the short reaction times, and the ease of product isolation highlight the inherent practicality of the developed method.
- Jain, Isha,Malik, Payal
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supporting information
p. 93 - 97
(2021/11/26)
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- A PROCESS FOR THE PREPARATION OF UPADACITINIB AND ITS INTERMEDIATES
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The present invention provides novel intermediates of formula IV and formula VI, which are key intermediates in the process of Upadacitinib.
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Page/Page column 5; 6
(2021/09/11)
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- Preparation method of carbamate
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The invention belongs to the technical field of synthesis of amino and carboxyl compounds connected to the same carbon frame through urea alcoholysis, and particularly relates to a preparation methodof carbamate. The preparation method of the carbamate comprises the following steps of: sequentially introducing urea, alcohol and a catalyst into a reactor, sealing, and reacting at 90-120 DEG C for8-12 hours to obtain the carbamate, wherein the catalyst includes an alumina supported metal oxide. By adopting the method for preparation of the carbamate, the side reaction of urea decomposition canbe effectively avoided, impurities such as carbamate are not detected, and the yield of the carbamate is high.
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Paragraph 0055; 0059-0061
(2020/09/23)
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- Triazinetriamine-derived porous organic polymer-supported copper nanoparticles (Cu-NPs@TzTa-POP): an efficient catalyst for the synthesis of: N -methylated products via CO2fixation and primary carbamates from alcohols and urea
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In recent times, carbon dioxide fixation has received much attention for its potential application as an abundant C1 source and a range of important fine chemicals can be manufactured via this fixation. Here, a copper nanoparticle-decorated porous organic polymer-based (Cu-NPs@TzTa-POP) material was prepared by a simple in situ process. The catalyst was characterized by various techniques such as UV-vis spectra, FTIR spectra, HR-TEM, PXRD, N2 adsorption-desorption, TG-DTA, XPS, and AAS analysis. The synthesized heterogeneous catalyst showed excellent activity in an atmospheric carbon dioxide fixation reaction to produce N-methylated products from aromatic/heterocyclic amines in the presence of polymethyl-hydrosiloxane (PMHS) as the reducing agent at 80 °C within 12 h of the reaction. Through this catalytic N-methylation reaction, we obtained 98% yield of the product with turnover frequency ranging from 18 to 42 h-1. The catalyst is also very stable for the formation of primary carbamates from alcohols using the eco-friendly carbonylating agent, urea. Diverse alcohols (such as benzylic alcohols, phenols, heterocyclic alcohols, as well as aliphatic alcohols) showed much acceptance to this catalytic reaction and produced moderate to excellent yields of the respective carbamate products under ambient reaction conditions. Moreover, Cu-NPs@TzTa-POP is effortlessly recyclable and reusable without the extensive loss of active copper metal centres for many catalytic rounds (up to six catalytic rounds were examined).
- Haque, Najirul,Biswas, Surajit,Basu, Priyanka,Haque Biswas, Imdadul,Khatun, Resmin,Khan, Aslam,Islam, Sk Manirul
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supporting information
p. 15446 - 15458
(2020/10/22)
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- An efficient one-pot synthesis of industrially valuable primary organic carbamates and: N -substituted ureas by a reusable Merrifield anchored iron(ii)-anthra catalyst [FeII(Anthra-Merf)] using urea as a sustainable carbonylation source
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An efficient synthesis of primary carbamates and N-substituted ureas is explored with a newly developed heterogeneous polymer supported iron catalyst in the presence of a sustainable carbonylation source. The Merrifield anchored iron(ii)-anthra catalyst [FeII(Anthra-Merf)] was synthesized by functionalization of Merrifield polymer followed by grafting of iron metal. The catalyst [FeII(Anthra-Merf)] was characterized by several techniques, like SEM, EDAX, TGA, PXRD, XPS, FTIR, CHN, AAS and UV-Vis analysis. The designed polymer embedded [FeII(Anthra-Merf)] complex is a remarkably successful catalyst for the synthesis of primary organic carbamates and N-substituted ureas by using safe carbonylation agent urea with different derivatives of alcohols and amines, respectively. The reported catalyst is a potential candidate towards contributing a satisfactory yield of isolated products under suitable reaction conditions. The catalyst is recyclable and almost non-leaching in nature after six runs with an insignificant drop in catalytic activity. Thus we found an economical and viable catalyst [FeII(Anthra-Merf)] for primary carbamates and N-substituted urea synthesis under moderate reaction conditions.
- Basu, Priyanka,Dey, Tusar Kanto,Ghosh, Aniruddha,Biswas, Surajit,Khan, Aslam,Islam, Sk. Manirul
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p. 2630 - 2643
(2020/02/20)
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- Discovery of a dual tubulin polymerization and cell division cycle 20 homologue inhibitor via structural modification on apcin
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Apcin is one of the few compounds that have been previously reported as a Cdc20 specific inhibitor, although Cdc20 is a very promising drug target. We reported here the design, synthesis, and biological evaluations of 2,2,2-trichloro-1-aryl carbamate derivatives as Cdc20 inhibitors. Among these derivatives, compound 9f was much more efficient than the positive compound apcin in inhibiting cancer cell growth, but it had approximately the same binding affinity with apcin in SPR assays. It is possible that another mechanism of action might exist. Further evidence demonstrated that compound 9f also inhibited tubulin polymerization, disorganized the microtubule network, and blocked the cell cycle at the M phase with changes in the expression of cyclins. Thus, it induced apoptosis through the activation of caspase-3 and PARP. In addition, compound 9f inhibited cell migration and invasion in a concentration-dependent manner. These results provide guidance for developing the current series as potential new anticancer therapeutics.
- Huang, Pan,Le, Xiangyang,Huang, Fei,Yang, Jie,Yang, Haofeng,Ma, Junlong,Hu, Gaoyun,Li, Qianbin,Chen, Zhuo
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p. 4685 - 4700
(2020/06/08)
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- An Fe3O4@SiO2/Schiff base/Cu(ii) complex as an efficient recyclable magnetic nanocatalyst for selective mono: N-arylation of primary O-alkyl thiocarbamates and primary O-alkyl carbamates with aryl halides and arylboronic acids
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An efficient, convenient and novel method for the selective mono N-arylation of primary O-alkyl thiocarbamates and primary O-alkyl carbamates with aryl halides and arylboronic acids in the presence of a recyclable magnetic Cu(ii) nanocatalyst is described. A variety of mono N-arylated O-alkyl thiocarbamates and O-alkyl carbamates were prepared in good to excellent yields with a broad range of aryl coupling partners. The magnetic nanocatalyst can be easily recovered with an external magnetic field and reused at least five times without noticeable leaching or loss of its catalytic activity. This cost-effective and eco-friendly methodology has some other advantages, such as easy preparation of the catalyst, simple workup procedure, and easy purification, which makes this protocol interesting for the users in various fields of pharmacology and biotechnology systems.
- Sardarian, Ali Reza,Dindarloo Inaloo, Iman,Zangiabadi, Milad
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p. 8557 - 8565
(2019/06/14)
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- Superparamagnetic Fe3O4 Nanoparticles in a Deep Eutectic Solvent: An Efficient and Recyclable Catalytic System for the Synthesis of Primary Carbamates and Monosubstituted Ureas
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Superparamagnetic Fe3O4 nanoparticles were used to synthesize various primary carbamates as well as monosubstituted and N,N-disubstituted ureas. This efficient phosgene-free process used urea as an eco-friendly carbonyl source in the presence of a biocompatible deep eutectic solvent (DES) to provide an inexpensive and attractive route that afforded the products in moderate to excellent yields. The employed DES serves both a catalytic role and as the green reaction medium. The magnetic nanocatalyst and DES can been reused several times without a significant loss of activity.
- Inaloo, Iman Dindarloo,Majnooni, Sahar,Esmaeilpour, Mohsen
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p. 3481 - 3488
(2018/07/29)
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- SnCl2-catalyzed synthesis of carbamates from renewable origin alcohols
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Effects of structure and reactivity of renewable origin alcohols in the conversion and selectivity of the SnCl2-catalyzed reactions in the presence and absence of urea were assessed. Convenient simple and suitable method for the synthesis of carbamates from renewable origin alcohols and urea in one-step are provided. We have assessed the activity of SnCl2 catalyst, a commercially affordable Lewis acid, in reactions of urea alcoholysis with different natural origin alcohols (geranyl, neryl, bornyl, cinnamyl, α-terpinyl and benzyl alcohols), aiming to synthesize carbamates, which are biologically active compounds, building blocks in organic synthesis and raw material to synthesize polyurethanes. The low cost of urea, the water tolerant catalyst and phosgene free reaction are positive aspects of this carbamates synthesis process. The different reaction pathways were assessed. A mechanism was proposed based on FT-IR experiments and experimental data.
- da Silva, Márcio José,Chaves, Diego Morais
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p. 1169 - 1180
(2019/01/28)
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- Selective Synthesis of Secondary Arylcarbamates via Efficient and Cost Effective Copper-Catalyzed Mono Arylation of Primary Carbamates with Aryl Halides and Arylboronic Acids
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Abstract: An efficient, selective and cost-effective procedure has been developed for mono N-arylation of primary alkyl and benzyl carbamates with aryl iodides and bromides by incorporating CuI as an inexpensive and commercially available catalyst. Despite previous reports on C–N coupling reactions, this process does not need expensive ligands and takes advantage of readily available and inexpensive ethylenediamine (EDA) as the ligand. Reaction times were relatively short and related N-arylated carbamates were obtained in excellent yields. Interestingly, replacing CuI with Cu(OAc)2 allowed us to use arylboronic acids as coupling partner for this reaction. All products are well characterized by 1H- and 13C-NMR, MS, melting point, IR and CHNS techniques.
- Sardarian, Ali Reza,DindarlooInaloo, Iman,Zangiabadi, Milad
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p. 642 - 652
(2018/01/11)
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- Design and Synthesis of Iminosydnones for Fast Click and Release Reactions with Cycloalkynes
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Emerging applications in the field of chemical biology are currently limited by the lack of bioorthogonal reactions allowing both removal and linkage of chemical entities on complex biomolecules. We recently discovered a novel reaction between iminosydnones and strained alkynes leading to two products resulting from ligation and fragmentation of iminosydnones under physiological conditions. We now report the synthesis of a panel of substituted iminosydnones and the structure reactivity relationship between these compounds and strained alkyne partners. This study identified the most relevant substituents, which allow to increase the rate of the transformation and to develop a bifunctional cleavable linker with improved kinetics.
- Riomet, Margaux,Decuypere, Elodie,Porte, Karine,Bernard, Sabrina,Plougastel, Lucie,Kolodych, Sergii,Audisio, Davide,Taran, Frédéric
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supporting information
p. 8535 - 8541
(2018/05/30)
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- Iron-catalyzed reaction of urea with alcohols and amines: A safe alternative for the synthesis of primary carbamates
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A general study of the iron-catalyzed reaction of urea with nucleophiles is here presented. The carbamoylation of alcohols allows for the synthesis of N-unsubstituted (primary) carbamates, including present drugs (Felbamate and Meprobamat, without the necessity to apply phosgene and related derivatives. Using amines as nucleophiles gave rise to the respective mono-and disubstituted ureas via selective transamidation reaction. These atom-economical transformations provide a direct and selective access to valuable compounds from cheap and readily available urea using a simple Lewis-acidic iron(Icatalyst.
- Pe?a-López, Miguel,Neumann, Helfried,Beller, Matthias
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p. 2233 - 2238
(2017/07/25)
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- Fe3O4@SiO2/Schiff base/Pd complex as an efficient heterogeneous and recyclable nanocatalyst for chemoselective: N -arylation of O -alkyl primary carbamates
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An efficient, heterogeneous and cost effective method has been developed using an Fe3O4@SiO2/Schiff base/Pd complex as a magnetic and easily recyclable nanocatalyst for rapid and effective N-arylation of carbamates in good to excellent yield. The catalyst can be easily recovered and reused over six runs without significant decrease in the activity. Further highlights of this protocol are operational simplicity, versatility and relatively short reaction times.
- Sardarian,Zangiabadi,Inaloo, I. Dindarloo
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p. 92057 - 92064
(2016/10/11)
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- A synthetic approach to N -aryl carbamates via copper-catalyzed Chan-Lam coupling at room temperature
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A mild and efficient synthesis of N-arylcarbamates was achieved by reacting azidoformates with boronic acids in the presence of 10 mol % of copper chloride catalyst. The reaction proceeds readily in an open flask at room temperature without additional base, ligand, or additive. Rapid access to urea analogues via a two-step one-pot procedure is enabled by reacting N-arylcarbamates with aluminum-amine complexes. In addition, among several boronic acid derivatives prepared, dimethylphenyl boronate was found to react rapidly in its reaction with benzyl azidoformate, invoking in situ generation of this species in the catalytic cycle.
- Moon, Soo-Yeon,Kim, U. Bin,Sung, Dan-Bi,Kim, Won-Suk
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p. 1856 - 1865
(2015/02/19)
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- Selective access to e - And Z -ΔIle-containing peptides via a stereospecific E2 dehydration and an O → N acyl transfer
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A concise synthesis of peptides that contain E- or Z-dehydroisoleucine (ΔIle) residues is reported. The key reaction is an unusual anti dehydration of β-tert-hydroxy amino acid derivatives that is mediated by the Martin sulfurane. A subsequent tandem Staudinger reduction-O → N acyl transfer process forges an amide bond to the ΔIle residue with minimal E/Z alkene isomerization. Density functional calculations attribute the stereospecific dehydration to a highly asynchronous E2 anti process.
- Ma, Zhiwei,Jiang, Jintao,Luo, Shi,Cai, Yu,Cardon, Joseph M.,Kay, Benjamin M.,Ess, Daniel H.,Castle, Steven L.
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supporting information
p. 4044 - 4047
(2014/08/18)
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- Serine-selective aerobic cleavage of peptides and a protein using a water-soluble copper-organoradical conjugate
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The site-specific cleavage of peptide bonds is an important chemical modification of biologically relevant macromolecules. The reaction is not only used for routine structural determination of peptides, but is also a potential artificial modulator of protein function. Realizing the substrate scope beyond the conventional chemical or enzymatic cleavage of peptide bonds is, however, a formidable challenge. Here we report a serine-selective peptide-cleavage protocol that proceeds at room temperature and near neutral pH value, through mild aerobic oxidation promoted by a water-soluble copper-organoradical conjugate. The method is applicable to the site-selective cleavage of polypeptides that possess various functional groups. Peptides comprising D-amino acids or sensitive disulfide pairs are competent substrates. The system is extendable to the site-selective cleavage of a native protein, ubiquitin, which comprises more than 70 amino acid residues.
- Seki, Yohei,Tanabe, Kana,Sasaki, Daisuke,Sohma, Youhei,Oisaki, Kounosuke,Kanai, Motomu
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p. 6501 - 6505
(2014/06/24)
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- Ammonolysis of anilides promoted by ethylene glycol and phosphoric acid
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Ethylene glycol (EG) and phosphoric acid have been found to promote the ammonolysis of a variety of diverse anilides as well as N-aryl carbamate, phthalimide, and urea substrates in the absence of transition metals or other Lewis acid promoters.
- Stephenson, Nickeisha A.,Gellman, Samuel H.,Stahl, Shannon S.
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p. 46840 - 46843
(2014/12/10)
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- Reduction of hydrazines to amines with low-valent titanium reagent
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The N,N bond cleavage in hydrazines to amines via low-valent titanium reagent prepared in situ by treatment of TiCl4 with Mg powder in THF or CH2Cl2-Et2O is described. The reaction proceeds smoothly under mild conditions to afford amines in good to excellent yields with diverse functional group tolerance such as chloride, methoxyl, benzyloxyl, ester, acyl, as well as C,C double bonds and benzyl-nitrogen bonds. ARKAT-USA, Inc.
- Ren, Fang,Zhang, Yan,Hu, Lan,Luo, Meiming
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p. 165 - 173
(2013/06/27)
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- Bromenium-catalysed tandem ring opening/cyclisation of vinylcyclopropanes and vinylcyclobutanes: A metal-free [3+2+1]/[4+2+1] cascade for the synthesis of chiral amidines and computational investigation
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We present a detailed study of a [3+2+1] cascade cyclisation of vinylcyclopropanes (VCP) catalysed by a bromenium species (Br δ+-Xδ-) generated in situ, which results in the synthesis of chiral bicyclic amidines in a tandem one-pot operation. The formation of amidines involves the ring-opening of VCPs with Br-X, followed by a Ritter-type reaction with chloramine-T and a tandem cyclisation. The reaction has been further extended to vinylcyclobutane systems and involves a [4+2+1] cascade cyclisation with the same reagents. The versatility of the methodology has been demonstrated by careful choice of VCPs and VCBs to yield bicyclo[4.3.0]-, -[4.3.1]- and -[4.4.0]amidines in enantiomerically pure form. On the basis of the experimental observations and DFT calculations, a reasonable mechanism has been put forth to account for the formation of the products and the observed stereoselectivity. We propose the existence of a π-stabilised homoallylic carbocation at the cyclopropane carbon as the reason for high stereoselectivity. DFT studies at B3LYP/6-311+G** and M06-2X/6-31+G* levels of theory in gas-phase calculations suggest the ring-opening of VCP is initiated at the π-complex stage (between the double bond and Br-X). This can be clearly perceived from the solution-phase (acetonitrile) calculations using the polarisable continuum model (PCM) solvation model, from which the extent of the ring opening of VCP was found to be noticeably high. Studies also show that the formation of zero-bridge bicyclic amidines is favoured over other bridged bicyclic amidines. The energetics of competing reaction pathways is compared to explain the product selectivity. Copyright
- Ganesh, Venkataraman,Sureshkumar, Devarajulu,Chanda, Debasree,Chandrasekaran, Srinivasan
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supporting information
p. 12498 - 12511,14
(2020/08/24)
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- Osmium-catalyzed vicinal oxyamination of alkenes by N-(4- toluenesulfonyloxy)carbamates
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N-(4-Toluenesulfonyloxy)carbamates based on a range of common amine protecting groups serve as preformed nitrogen sources in the intermolecular osmium-catalyzed oxyamination reaction of a variety of mono-, di-, and trisubstituted alkenes. The reactions occur with low catalyst loadings and good yields and afford high regioselectivity for unsymmetrically substituted alkenes.
- Masruri,Willis, Anthony C.,McLeod, Malcolm D.
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p. 8480 - 8491
(2012/11/13)
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- Reduction of hydrazines to amines with aqueous solution of titanium(iii) trichloride
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N-N bond cleavage in hydrazines is widely used in the preparation of amines and thus occupies a significant place in organic synthesis. In this paper, we report a new method for the reductive cleavage of N-N bonds in hydrazines by commercially available and cheap aqueous titanium(iii) trichloride. The reaction proceeds smoothly under a broad pH range from acidic to neutral and basic conditions to afford amines in good yields. This method is compatible with substrates containing functionalities such as C-C double bonds, benzyl-nitrogen bonds, benzyloxy and acyl groups. The Royal Society of Chemistry 2011.
- Zhang, Yan,Tang, Qiang,Luo, Meiming
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p. 4977 - 4982
(2011/08/05)
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- Calcium-catalyzed direct amination of π-activated alcohols
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A calcium-catalyzed direct amination of π-activated alcohols with different nitrogen nucleophiles under very mild reaction conditions is presented. The high reactivity of the calcium catalyst allows for an efficient conversion of secondary and tertiary benzylic and allylic as well as tertiary propargylic alcohols. Nitrogen nucleophiles such as carbamates, tosylamides and anilines are readily alkylated at room temperature.
- Haubenreisser, Stefan,Niggemann, Meike
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supporting information; scheme or table
p. 469 - 474
(2011/04/16)
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- A facile synthesis of imino-protected cyclic guanidine derivatives from diamines
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A convenient one-step synthesis of five-membered or six-membered imino-protected cyclic guanidine via an intramolecular ring-closure reaction of alkyl diamine (2a-2g) with 1, 3-diamino-protected methylisothiourea (1a and 1b) was established and investigated. Amino guanidine such as 3-(2-aminoethyl)-1, 2-dibenzyloxycarbonylguanidine (4a) has been proved to be the intermediate of the reaction via utilizing mono-protected diamine as starting material. The intramolecular ring closure of 4a results in 2- benzyloxycarbonyliminoimidazolidine (3a). This new one-step synthesis has advantages of simple condition, easy workup procedure and reasonable yield.
- Yuan, Jian Hai,Yang, Xiao Xiao,Lin, Hao,Wang, De Xin
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p. 1399 - 1402
(2012/06/18)
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- The "borrowing hydrogen strategy" by supported ruthenium hydroxide catalysts: Synthetic scope of symmetrically and unsymmetrically substituted amines
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The N-alkylation of ammonia (or its surrogates, such as urea, NH 4HCO3, and (NH4)2CO3) and amines with alcohols, including primary and secondary alcohols, was efficiently promoted under anaerobic conditions by the easily prepared and inexpensive supported ruthenium hydroxide catalyst Ru(OH)x/TiO2. Various types of symmetrically and unsymmetrically substituted "tertiary" amines could be synthesized by the N-alkylation of ammonia (or its surrogates) and amines with "primary" alcohols. On the other hand, the N-alkylation of ammonia surrogates (i.e., urea and NH 2HCO3) with "secondary" alcohols selectively produced the corresponding symmetrically substituted "secondary" amines, even in the presence of excess amounts of alcohols, which is likely due to the steric hindrance of the secondary alcohols and/or secondary amines produced. Under aerobic conditions, nitriles could be synthesized directly from alcohols and ammonia surrogates . The observed catalysis for the present N-alkylation recations was intrinsically heterogeneous, and the retrieved catalyst could be reused without any significant loss of catalytic performance. The present catalytic transformation would proceed through consecutive N-alkylation reactions, in which alcohols act as alkylating reagents. On the basis of deuterium-labeling experiments, the formation of the ruthenium dihydride species is suggested during the N-alkylation reactions.
- Yamaguchi, Kazuya,He, Jinling,Oishi, Takamichi,Mizuno, Noritaka
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scheme or table
p. 7199 - 7207
(2010/09/05)
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- Carbamate derivatives of felbamate as potential anticonvulsant agents
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Several monocarbamate compounds derived from felbamate were synthesized and 11 target compounds (1, 4, and 6-14) were initially evaluated in mice MES and PTZ models in our laboratory. Carbamate compounds with varying substituents on the oxygen (1-4) gave anticonvulsant activity with a wide range of ED 50 in MES test from 300 mg/kg (4) and compounds with different groups on the nitrogen (5-14) also were quite active in the range of 15 mg/kg (14) to 170.5 mg/kg (6). This suggested that the spatial limitation in the MES model seemed flexible especially on the nitrogen end. All tested compounds showed some activity against mice scPTZ test, but none had the ED50 value 50 mg/kg. Ten selected compounds (1 and 6-14) for subsequent pharmacological evaluation in NIH all gave positive mice MES activity except 8 and 9, which were unexpectedly active in rats after further evaluations. Among the compounds, 1, 8, and 9 advanced to the quantitative study and 1 and 9 provided the highest PI values, 15 and 21, respectively, in the rat oral MES test.
- Kung, Ching-Hsin,Kwon, Chul-Hoon
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body text
p. 498 - 513
(2011/03/19)
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- Photochemistry of 5-allyloxy-tetrazoles: Steady-state and laser flash photolysis study
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The photochemistry of three 5-allyloxy-tetrazoles, in methanol, acetonitrile and cyclohexane was studied by product analysis and laser flash photolysis. The exclusive primary photochemical process identified was molecular nitrogen elimination, with formation of 1,3-oxazines. These compounds were isolated in reasonable yields by column chromatography on silica gel and were fully characterized. DFT(B3LYP)/6-31G(d,p) calculations predict that these 1,3-oxazines can adopt two tautomeric forms (i) with the NH group acting as a bridge connecting the oxazine and phenyl rings and (ii) with the -N bridge and the proton shifted to the oxazine ring. Both tautomeric forms are relevant in the photolysis of oxazines in solution. Secondary reactions were observed, leading to the production of phenyl vinyl-hydrazines, enamines, aniline and phenyl-isocyanate. Transient absorption, detected by laser flash photolysis, is attributed to the formation of triplet 1,3-biradicals generated from the excited 5-allyloxy-tetrazoles. The 1,3-biradicals are converted to 1,6-biradicals by proton transfer, which, after intersystem crossing, decay to generate the products. Solvent effects on the photoproduct distribution and rate of decomposition are negligible.
- Frija,Khmelinskii,Serpa,Reva,Fausto,Cristiano
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scheme or table
p. 1046 - 1055
(2009/02/05)
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- Silica supported perchloric acid (HClO4-SiO2): an efficient reagent for the preparation of primary carbamates under solvent-free conditions
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The synthesis of primary carbamates from structurally diverse compounds containing a hydroxyl group has been performed in high yields and purity, and without any epimerization under solvent-free conditions using HClO4-SiO2 as a mild, convenient, and effective reagent. The procedure is operationally simple, efficient, and environmentally benign.
- Modarresi-Alam, Ali Reza,Khamooshi, Ferydoon,Nasrollahzadeh, Mahmoud,Amirazizi, Homeyra Alsadat
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p. 8723 - 8726
(2008/02/11)
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- Inhibition of p38 kinase using symmetrical and unsymmetrical diphenyl ureas
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This invention relates to the use of a group of aryl ureas in treating cytokine mediated diseases and proteolytic enzyme mediated diseases, and pharmaceutical compositions for use in such therapy.
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- PIPERAZINE AND HOMOPIPERAZINE COMPOUNDS
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Compounds are provided having a piperazine or homopiperazine ring which are useful in the treatment of thrombosis.
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- Efficient carbamate synthesis
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A method of preparing carbamates of the general formula RR′—N—CO2—R″ by reacting an amine with carbon dioxide and an organic electrophile in an anhydrous solvent in the presence of a cesium base, whereby carbamate synthesis is accomplished in good yield at mild temperatures, either in solution or on a solid support, and wherein R, R′, and R″ are hydrogen, alkyl of 1-18 carbon atoms, silyl, phenyl, benzyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, allyl, or heterocycle, which are widely used as industrial products, and as intermediates in organic synthesis.
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- Zwitterionic tachykinin receptor antagonists
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The present invention is directed to certain novel compounds represented by structural formula I: or a pharmaceutically acceptable salt thereof, wherein R3, R5, R6, R7, R8, R11, R12 R13, Q, W, X, Y and Z are defined herein. The invention is also concerned with pharmaceutical formulations comprising these novel compounds as active ingredients and the use of the novel compounds and their formulations in the treatment of certain disorders. The compounds of this invention are tachykinin receptor antagonists and are useful in the treatment of psychiatric disorders including depression and anxiety.
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- Anthranilic acid derivatives as multi drug resistance modulators
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Anthranilic acids of formula (I): wherein each of R to R9is an organic substituent, n is 0 or 1, m is 0 or an integer of 1 to 6, q is 0 or 1, X is a direct bond, O, S, —S—(CH2)por —O—(CHO2)p— wherein p is from 1 to 6 and Ar is an unsaturated carbocyclic or heterocyclic group, and the pharmaceutically acceptable salts thereof, have activity as inhibitors of P-glycoprotein and may thus be used, inter alia, as modulators of multidrug resistance in the treatment of multidrug resistant cancers, for example to potentiate the cytotoxicity of a cancer drug.
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- Oxazolidinone antibacterial agents having a thiocarbonyl functionality
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The present invention provides compounds of Formula 1 or pharmaceutical acceptable salts thereof wherein A, G and R, are as defined in the claims which are antibacterial agents.
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- Convergent process for the preparation of a growth hormone secretagogue
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The present invention is directed to a novel convergent process for the preparation of the compound N-[1(R)-[(1,2-dihydro-1-methanesulfonyl-spiro[3H-indole-3,4'-piperdin]-1'-yl)carbonyl]-2-(phenylmethyl-oxy)ethyl]-2-amino-2-methyl-propanamide, and salts thereof, which has the structure: and which has the ability to stimulate the release of natural or endogenous growth hormone. This compound may be used to treat conditions which require the stimulation of growth hormone production or secretion such as in humans with a deficiency of natural growth hormone or in animals used for food or wool production where the stimulation of growth hormone will result in a larger, more productive animal.
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- Method of using calcilytic compounds
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The present invention features calcilytic compounds. "Calcilytic compounds" refer to compounds able to inhibit calcium receptor activity. Also described are the use of calcilytic compounds to inhibit calcium receptor activity and/or achieve a beneficial effect in a patient; and techniques which can be used to obtain additional calcilytic compounds.
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- SULFONAMIDE INHIBITORS OF ASPARTYL PROTEASE
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This invention provides a novel class of sulfonamide compounds of formula I which are aspartyl protease inhibitors: STR1 This invention also provides pharmaceutical compositions comprising these compounds. The compounds and pharmaceutical compositions of this invention are particularly well suited for inhibiting HIV-1 and HIV-2 protease activity and consequently, may be advantageously used as anti-viral agents against the HIV-1 and HIV-2 viruses. This invention also provides methods for inhibition aspartyl protease activity and methods for treating viral infections using the compounds and compositions of this invention.
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- Comformationally rigid bicyclic and adamantane derivatives useful as alpha 2-adrenergic blocking agents
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A compound of formula I in which: ring A is one of the five alternative multi-cyclic rings as shown wherein a dotted line adjacent to a bond indicates that a single bond or a double bond may be present at that position; X is nitrogen, oxygen or sulfur; R is hydrogen, lower straight or branched chain alkyl of 1 to 6 carbon atoms, or lower straight or branched chain alkenyl of 2 to 6 carbon atoms, a cycloaliphatic ring of 3 to 6 carbon atoms, phenyl optionally mono- or di-substituted with hydroxy, halogen, alkyl of 1 to 3 carbon atoms or alkoxy of 1 to 2 carbon atoms, or methylenedioxyphenyl; or a stereoisomer, or a pharmaceutically acceptable salt thereof. These compounds have alpha 2 receptor blocking activity and hence find use in the treatment or palliation of elevated intraocular pressure, non insulin-dependent diabetes, male impotence and obesity.
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- Oxazolidinone derivatives and pharmaceutical compositions
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A compound of Formula I: STR1 or a pharmaceutically acceptable salt thereof, which is antimicrobial agents, effective against various human and veterinary pathogens, including gram positive aerobic organisms, gram negative organisms, and anaerobic organisms.
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- New facile alkoxycarbonylating agent, alkyl pyrazole-1-carboxylates. The preparation and the utilities
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Alkyl pyrazole-1-carboxylates (2), which were readily prepared from alkyl chloroformate or carbazate in good yields, were provided as the new facile alkoxycarbonylating agents toward the Grignard reagents for the synthesis of one carbon higher carboxylic esters. Also amines were alkoxycarbonylated by 2 to produce the corresponding urethanes even in an aqueous medium. Benzyl 3,5-dimethylpyrazole-1-carboxylate (2d) could be utilized for the Cbz-protection of amino acids and esters in good yield without any racemization.
- Kashima, Choji,Tsuruoka, Shiro,Mizuhara, Saori
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p. 14679 - 14688
(2007/10/03)
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- Investigation of dialkyltin compounds as catalysts for the synthesis of dialkyl carbonates from alkyl carbamates
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New syntheses for dibutyldimethoxytin, dibutyldiisocyanatotin and 1,1,3,3-tetrabutyl-1,3-diisocyanatodistannoxane as well as the novel compounds dibutylisocyanatomethoxytin and 1,1,3,3-tetrabutyl-1-methoxy-3-isocyanatodistannoxane are described. These com
- Suciu, Elena N.,Kuhlmann, Barbara,A. Knudsen, George,Michaelson, Robert C.
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- A simple and efficient procedure for the synthesis of optically active 4-methoxy-α-methylphenylethylamine from tyrosine
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Optically active 4-methoxy-α-methylphenylethylamine (1), a useful chiral building block in medicinal chemistry, was synthesized from L- or D- tyrosine by using a simple and efficient procedure via one-pot zinc reduction of the corresponding O-tosylate (4) in the presence of H2O and NaI in pure form.
- Kohno, Harumichi,Iwakuma, Takeo,Yamada, Koichiro
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p. 1935 - 1945
(2007/10/03)
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- Process for producing ecteinascidin compounds
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The present invention is directed to a synthetic process for the formation of ecteinascidin compounds and related structures, such as the saframycins. In one particularly preferred embodiment, the present invention provides a synthetic route for the formation of ecteinascidin 743 (1), STR1 an exceedingly potent and rare marine-derived antitumor agent which is slated for clinical trials. The process of this invention is enantio- and stereocontrolled, convergent and short. Also disclosed are novel process intermediates, useful not only in the total synthesis of ecteinascidin 743, but also other known ecteinascidin compounds, including derivatives and analogs thereof.
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- CONFORMATIONALLY RIGID BICYCLE AND ADAMANTANE DERIVATIVES USEFUL AS ALPHA2-ADRENERGIC BLOCKING AGENTS
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A compound of formula I STR1 in which: ring A is one of the five alternative multi-cyclic rings as shown wherein a dotted line adjacent to a bond indicates that a single bond or a double bond may be present at that position; X is nitrogen, oxygen or sulfur; R is hydrogen, lower straight or branched chain alkyl of 1 to 6 carbon atoms, or lower straight or branched chain alkenyl of 2 to 6 carbon atoms, a cycloaliphatic ring of 3 to 6 carbon atoms, phenyl optionally mono-or di-substituted with hydroxy, halogen, alkyl of 1 to 3 carbon atoms or alkoxy of 1 to 2 carbon atoms, or methylenedioxyphenyl; or a stereoisomer, or a pharmaceutically acceptable salt thereof.These compounds have α 2 receptor blocking activity and hence find use in the treatment or palliation of elevated intraocular pressure, non insulin-dependent diabetes, male impotence and obesity.
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- Polymorphic forms of a growth hormone secretagogue
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This invention is concerned with polymorphic forms of the compound N-?1(R)-?(1,2-dihydro-1-methanesulfonylspiro?3H-indole-3,4'-piperdin!-1'-yl)carbonyl!-2-(phenylmethyloxy)ethyl!-2-amino-2-methylpropanamide methanesulfonate which is a growth hormone secretagogue that is useful in food animals to promote their growth thereby rendering the production of edible meat products more efficient, and in humans, to treat physiological or medical conditions characterized by a deficiency in growth hormone secretion, and to treat medical conditions which are improved by the anabolic effects of growth hormone. The instant polymorphic forms have advantages over the other known forms of N-?1(R)-?(1,2-dihydro-1-methanesulfonylspiro?3H-indole-3,4'-piperdin!-1'-yl)carbonyl!-2-(phenylmethyloxy)-ethyl!-2-amino-2-methylpropanamide methanesulfonate in terms of thermodynamic stability and suitability for inclusion in pharmaceutical formulations. The present invention is also concerned with processes for preparing these polymorphic forms, pharmaceutical formulations comprising these polymorphic forms as active ingredients and the use of the polymorphic form of the compound and their formulations in the treatment of certain disorders.
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- Inhibitors of peptide binding to MHO class II proteins
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Compounds of the formula STR1 are inhibitors of peptide binding to major histocompatibility complex type II proteins and are useful in the treatment and prevention of autoimmune diseases including: rheumatoid arthritis, Type I diabetes, multiple sclerosis, lupus erythematosis, Graves disease and pemphigus. The present invention also provides novel compositions, methods of treatment employing the compounds of the present invention and methods of manufacture of the compounds of structural formula (I).
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- One-pot synthesis of protected homoallyl amines
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An efficient one-pot procedure for the synthesis of protected homoallyl amines from aldehydes or aldehyde acetals, carbamates and allyltrimethylsilane under influence of borontrifluoride etherate was developed. Scope and limitations of the aldehyde and carbamate components are reported.
- Veenstra, Siem J.,Schmid, Priska
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p. 997 - 1000
(2007/10/03)
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- Oxazolidinone derivatives and pharmaceutical compositions containing them
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The present invention provides agents having high antimicrobial activity for preventing and treating infectious diseases. Thus, the present invention provides novel oxazolidinone derivatives represented by chemical formula (I), or pharmaceutically acceptable salts thereof, as well as antimicrobial compositions containing said derivatives or salts thereof as active ingredients. STR1
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