- Green Regio- and Enantioselective Aminolysis Catalyzed by Graphite and Graphene Oxide under Solvent-Free Conditions
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The ring-opening reactions of epoxides with amines were efficiently and regioselectively catalyzed by high-surface-area graphite and graphene oxide under metal-free and solvent-free conditions. For epoxides without aryl groups, catalytic activity was observed only for graphene oxide, and hence, the activity must have been due to its acidic groups. For styrene oxide, instead, graphite and graphene oxide exhibited rather similar catalytic activities, and hence, the activity was mainly due to activation of the electrophilic epoxide by π-stacking interactions with the graphitic π system. The described aminolysis procedure is green and cheap because the catalyst can be recovered and recycled without loss of efficiency. Moreover, these heterogeneous catalysts exert high stereoselective control in the presence of nonracemic epoxides and provide chiral β-amino alcohols with enantiomeric excess values up to 99 %.
- Acocella, Maria Rosaria,D'Urso, Luciana,Maggio, Mario,Guerra, Gaetano
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p. 1915 - 1920
(2016/07/06)
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- Development of an optimized process for the preparation of 1-benzylazetidin-3-ol: An industrially important intermediate for substituted azetidine
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A thoroughly optimized and robust process for the synthesis of 1-benzylazetidin-3-ol has been emphasized. 1-Benzylazetidin-3-ol has been utilized as a starting material in the commercial synthesis of azetidin-3-ol hydrochloride. Synthesis of azetidin-3-ol hydrochloride involves the usage of very low cost and commercially available starting material (benzylamine) and with reduced formation of di(3-chloro-2-hydroxypropyl) benzylamine significantly resulting in an economical process that allows the effective production of 1-benzyl azetidin-3-ol as well as azetidin-3-ol hydrochloride.
- Krishna Reddy,Udaykiran,Chintamani,Mahesh Reddy,Kameswararao, Ch.,Madhusudhan
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experimental part
p. 462 - 466
(2012/01/17)
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- Highly regioselective and efficient synthesis of aminoepoxides by ring closure of aminohalohydrins mediated by KF-Celite
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The regioselective synthesis of several aminoepoxides has been achieved without observing any trace of azetidinols, which are usually reported as the exclusive reaction products when aminohalohydrins are treated with bases. The use of the mild supported base KF-Celite in refluxing acetonitrile is crucial for modulating the excellent regioselectivity observed. Georg Thieme Verlag Stuttgart . New York.
- Pace, Vittorio,Hoyos, Pilar,Sinisterra, José Vicente,Alcántara, Andrés R.,Holzer, Wolfgang
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supporting information; experimental part
p. 1831 - 1834
(2011/09/16)
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- Seebach's conjunctive reagent enables double cyclizations
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(Figure presented) When ketones flanked on both sides by nucleophilic atoms react with Seebach's nitropropenyl pivaloate reagent, direct couplings take place to give two new ring systems and three bonds. Cis-ring fusions are observed in unions leading to 5,5-, 5,6-, and 6,6-bicycles. Densely functionalized and rigid frameworks may be rapidly formed by the chemistry described herein.
- Chandler, Brent D.,Roland, Jason T.,Li, Yukai,Sorensen, Erik J.
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supporting information; experimental part
p. 2746 - 2749
(2010/09/04)
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- DMAP-catalyzed synthesis of 2-oxazolidinones from corresponding halohydrins using KOCN/DMF
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We report facile and simple synthesis of a variety of 2-oxazolidinones from the corresponding halohydrins by reaction with KOCN in DMF catalyzed by DMAP. DMAP and temperature play key roles in enriching the yield of 2-oxazolidinones. A few examples in this Letter are applicable to pharmaceutically important processes.
- Chinnam Naidu,Ravi Babu,Gangaiah,Mukkanti,Madhusudhan
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experimental part
p. 1226 - 1229
(2010/04/23)
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- Catalyst-free process for the synthesis of 5-aryl-2-oxazolidinones via cycloaddition reaction of aziridines and carbon dioxide
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A simple approach for facile synthesis of 5-aryl-2-oxazolidinones in excellent regioselectivity from aziridines under compressed CO2 conditions was developed in the absence of any catalyst and organic solvent. The reaction outcome was found to be tuned by subtly adjusting CO2 pressure. The adduct formed in situ of aziridine and CO2 is assumed to act as a catalyst in this reaction, which was also studied by means of in situ FT-IR technique.
- Dou, Xiao-Yong,He, Liang-Nian,Yang, Zhen-Zhen,Wang, Jing-Lun
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supporting information; experimental part
p. 2159 - 2163
(2010/10/21)
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- ACID ADDITION SALTS OF SYNTHETIC INTERMEDIATES FOR CARBAPENEM ANTIBIOTICS AND PROCESSES FOR PREPARING THE SAME
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The present invention provides a process for preparing an acid addition salt of a synthetic intermediate for carbapenem antibiotics and a novel acid addition salt of a synthetic intermediate for carbapenem antibiotics obtained from the process. The present invention also provides a process for preparing a carbapenem antibiotic using the acid addition salt. According to the process of the present invention, an acid addition salt of a synthetic intermediate for carbapenem antibiotics can be prepared in a high yield and high purity, without conducting column chromatography. Thus, the process of the present invention can be applied to mass production with an industrial scale. Furthermore, since the acid addition salts have solid forms, they are easy to handle and keep in a manufacturing site.
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Page/Page column 8
(2010/12/26)
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- ACID ADDITION SALTS OF SYNTHETIC INTERMEDIATES FOR CARBAPENEM ANTIBIOTICS AND PROCESSES FOR PREPARING THE SAME
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The present invention provides a process for preparing an acid addition salt of a synthetic intermediate for carbapenem antibiotics and a novel acid addition salt of a synthetic intermediate for carbapenem antibiotics obtained from the process. The present invention also provides a process for preparing a carbapenem antibiotic using the acid addition salt. According to the process of the present invention, an acid addition salt of a synthetic intermediate for carbapenem antibiotics can be prepared in a high yield and high purity, without conducting column chromatography. Thus, the process of the present invention can be applied to mass production with an industrial scale. Furthermore, since the acid addition salts have solid forms, they are easy to handle and keep in a manufacturing site.
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Page/Page column 19
(2009/04/25)
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- A practical and facile synthesis of azetidine derivatives for oral carbapenem, L-084
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An orally active carbapenem L-084, which exhibits high bioavailability in humans, has a 1-(1,3-thiazolin-2-yl)azetidin-3-ylthio moiety at the C-2 position of the 1β-methylcarbapenem skeleton. We established a practical and cost-effective synthesis of 3-mercapto-1-(1,3-thiazolin-2-yl)azetidine (1) for further scale-up production of L-084. This synthesis method entails an industry-oriented reaction of azetidine ring-closure to yield N-benzyl-3-hydroxyazetidine (16), which is eventually converted to 1 via key intermediates, Bunte salts 19 and 20.
- Isoda, Takeshi,Yamamura, Itsuki,Tamai, Satoshi,Kumagai, Toshio,Nagao, Yoshimitsu
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p. 1408 - 1411
(2007/10/03)
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- 2-ARYLMETHYLAZETIDINE CARBAPENEM DERIVATIVES AND PREPARATION THEREOF
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A 2-arylmethylazetidine carbapenem derivative of formula ( I ) or a pharmaceutically acceptable salt thereof exhibits a wide spectrum of antibacterial activities against Gram-positive and Gram-negative bacteria and excellent antibacterial activities against resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) and quinolone-resistant strains (QRS).
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Page/Page column 9
(2008/06/13)
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- New Synthesis of Propargylic Amines from 2-(Bromomethyl)aziridines. Intermediacy of 3-Bromoazetidinium Salts
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A new, efficient, and straightforward synthesis provides propargylamines in high overall yields (64-77%) by transformation of 1-(arylmethyl)-2-(bromomethyl)aziridines into N,N-di(arylmethyl)N-(2-propynyl)amines via N-(2,3-dibromopropyl)amines and N-(2-bromo-2-propenyl)amines. The conversion of N-(2,3-dibromopropyl)amines into N-(2-bromo-2-propenyl)amines is based on a novel analogue of the Hofmann elimination. A Yamaguchi-Hirao alkylation, a Sonogashira coupling, or a hydroarylation reaction further functionalized these propargylamines toward potentially interesting compounds for medicinal and agrochemical use.
- D'Hooghe, Matthias,Van Brabandt, Willem,De Kimpe, Norbert
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p. 2703 - 2710
(2007/10/03)
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- Calcium trifluoromethanesulfonate-catalysed aminolysis of epoxides
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Aminolysis of epoxides catalysed by calcium trifluoromethanesulfonate under mild reaction conditions is described. The novel method is very efficient in the synthesis of wide variety of β-amino alcohols with high regio- and stereoselectivity.
- Cepanec, Ivica,Litvi?, Mladen,Mikulda?, Hrvoje,Bartolin?i?, Anamarija,Vinkovi?, Vladimir
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p. 2435 - 2439
(2007/10/03)
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- Novel diphenylalkyl piperazine derivatives with high affinities for the dopamine transporter
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The novel diphenyl piperazine derivatives containing the phenyl substituted aminopropanol moiety, including 1-[4,4-bis(4-fluorophenyl)butyl]-4-[2-hydroxy-3-(phenylamino)propyl]piperazine 1, which were modified at the connective between the diphenyl and piperazine moieties, have been found to be potent dopamine uptake inhibitors. To study the further structure-activity relationship (SAR) of these compounds, a new series was synthesized, with modifications at the 2-hydroxy-3-phenylaminopropyl moiety of 1. The series was evaluated for dopamine transporter (DAT) binding affinity with [3H]GBR12935 in rat striatal membranes. Most of the compounds showed moderate to high DAT binding affinities and some were approximately equivalent in activity to compound 1 or GBR12909 as a dopamine uptake inhibitor, with IC50 values of nanomolar range. The SAR suggested that on exhibiting a potent interaction with the DAT, there is probably a steric limitation around the benzene ring of the phenylamino moiety of 1, allowing only small-sized substituents with the exception of basic moieties at the 4-position. In addition, the SAR at the 3-amino-2-propanol moiety of 1 suggested that either the nitrogen atom with an electron donating substituent or the unsubstituted nitrogen atom and also the hydroxy group are desirable for elicitation of a potent DAT binding affinity.
- Kimura, Makoto,Masuda, Tomoko,Yamada, Koji,Mitani, Masaki,Kubota, Nobuo,Kawakatsu, Nobuyuki,Kishii, Kenichi,Inazu, Masato,Kiuchi, Yuji,Oguchi, Katsuji,Namiki, Takayuki
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p. 3953 - 3963
(2007/10/03)
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- Novel diphenylalkyl piperazine derivatives with dual calcium antagonistic and antioxidative activities
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Two types of novel diphenylalkyl piperazine derivatives containing the thio or aminopropanol moiety substituted by phenyl or benzyl group were synthesized, and evaluated for their calcium antagonistic and antioxidative activities. These compounds showed apparent inhibitions against KCl-induced contractions in isolated rat aorta. Among them, phenylamino compound 9 and benzylamino compound 13 also possessed potent inhibitory activities against auto-oxidative lipid peroxidations in canine brain homogenates. Two representative compounds 3a and 9 were evaluated for their inhibitory activities against KCl-induced contractions in isolated canine arteries (basilar, coronary, mesenteric, and renal). Both compounds showed the most potent inhibitions to basilar artery.
- Kimura, Makoto,Masuda, Tomoko,Yamada, Koji,Kubota, Nobuo,Kawakatsu, Nobuyuki,Mitani, Masaki,Kishii, Kenichi,Inazu, Masato,Namiki, Takayuki
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p. 1947 - 1950
(2007/10/03)
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- Novel Syntheses of 1,3,3-Trinitroazetidine
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Alternative methods for the synthesis of 1,3,3-trinitroazetidine (TNAZ) from epichlorohydrin, and benzhydrylamine have been developed.These approaches employ N-sulfonyl-3-(hydroxyimino)azetidines as penultimate intermediates and represent an improvement over previously published methods which require either diazo containing intermediates or involve low yielding procedures.Parallel methods employing N-benzhydryl- and N-benzyl-3-(hydroxyimino)azetidine were also investigated as alternate routes to TNAZ
- Katritzky, Alan R.,Cundy, Darren J.,Chen, Jie
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p. 271 - 276
(2007/10/02)
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- Preparation of Trimethylsilyl Ethers of 3-Azetidinols . Scope and Limitations
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Preparation of the trimethylsilyl ethers of 1-alkyl-3-azetidinols from-non-hindered primary amines and epichlorhydrin by conversion of the intermediate 1-(alkylamino)-3-chloro-2-propanols to their trimethylsilylethers by either N-(trimethylsilyl)acetamide or by 1-(trimethylsilyl)imidazole followed by ring closure in acetonitrile is described.This sequence of reactions fails for aromatic amines, but appears to be general for all primary aliphatic amines, although the condensation of hindered amines with epichlorhydrin occurs slowly.Several novel azetidinols, in which the N-alkyl substituent insefl contains a second heterocyclic system, are reported.In addition, the pKA's of several m- and p-substituted 1-benzylazetidinols correlates well with the Hammett equation.
- Higgins, Robert H.,Watson, Monique R.,Faircloth, William J.,Eaton, Quentin L.,Jenkins, Harvey
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p. 383 - 387
(2007/10/02)
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- The Effect of the Steric Requirements of Trialkylsilyl Ethers on Ring Closure of 1-(Benzylamino)-3-chloro-2-(trialkylsiloxy)propanes
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The ring closure of 1-(benzylamino)-3-chloro-2-(trialkylsiloxy)propanes to 1-benzyl-3-(trialkylsiloxy)azetidines was investigated.There appears to be little or no advantage in the use of trialkylsilyl substituents larger than trimethylsilyl.
- Higgins, Robert H.
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p. 1489 - 1491
(2007/10/02)
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- Preparation of 3-Azetidinols with Non-Bulky 1-Alkyl Substituents
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Cyclization of either the tetrahydropyranyl or trimethylsilyl ether of 1-(alkylamino)-3-chloro-2-propanols 1 followed by cleavage of the azetidinyl ether provides a general method for the preparation of 1-alkyl-3-azetidinols.Unhindered amines provide a more facile preparation of derivatives of 1, or its ethers, than do hindered amines, while hindered derivatives of 1 undergo more facile ring closure.
- Higgins, Robert H.,Eaton, Quentin L.,Worth, Leroy,Peterson, Myra V.
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p. 255 - 259
(2007/10/02)
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- Preparation of 1-benzylazetidin-3-ol
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1-Benzylazetidin-3-ol, a precursor to 3-carboxyazetidine, is prepared by heating N-benzyl-3-amino-1-chloropropan-2-ol in an aqueous medium, optionally treating the resulting hydrochloride salt with an alkali metal base.
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