- Photo-on-Demand Synthesis of Vilsmeier Reagents with Chloroform and Their Applications to One-Pot Organic Syntheses
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The Vilsmeier reagent (VR), first reported a century ago, is a versatile reagent in a variety of organic reactions. It is used extensively in formylation reactions. However, the synthesis of VR generally requires highly toxic and corrosive reagents such as POCl3, SOCl2, or COCl2. In this study, we found that VR is readily obtained from a CHCl3 solution containing N,N-dimethylformamide or N,N-dimethylacetamide upon photo-irradiation under O2 bubbling. The corresponding Vilsmeier reagents were obtained in high yields with the generation of gaseous HCl and CO2 as byproducts to allow their isolations as crystalline solid products amenable to analysis by X-ray crystallography. With the advantage of using CHCl3, which bifunctionally serves as a reactant and a solvent, this photo-on-demand VR synthesis is available for one-pot syntheses of aldehydes, acid chlorides, formates, ketones, esters, and amides.
- Liang, Fengying,Eda, Kazuo,Okazoe, Takashi,Wada, Akihiro,Mori, Nobuaki,Konishi, Katsuhiko,Tsuda, Akihiko
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p. 6504 - 6517
(2021/05/06)
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- acyl triazole derivative and its manufacturing method
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PROBLEM TO BE SOLVED: To provide a novel acyl triazole derivative that can be synthesized at low cost by a convenient method, has a comparable reactivity to an acid chloride with an amine compound and an alcohol compound, and can be safely handled, and a method of manufacturing the same; the acyl triazole derivative that is useful as a reactant applied to polymerization reaction to be continued; and a monomer comprising the same.SOLUTION: An acyl triazole derivative is shown by formula (1). In the formula, A denotes a substituted arylene group, a 1,3-phenylene group, a bisarylene group, a polycyclic arylene group, an alkylene group or an aralkylene group.
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Paragraph 0053
(2017/04/03)
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- PROCESS FOR PREPARING SOLID (CHLORINE METHYLENE) DIMETHYL AMMONIUM CHLORIDE
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Solid (chloro methylene) dimethyl ammonium chloride of in manufacturing method, said method, and phthalic anhydride raw material is first acyl with Neel thio chloride and method for chlorinating side is performed on the stacking section for stacking o-reel chloride, again chloride reel-o N, reacts with N-dimethylformamide (chloro methylene) dimethyl ammonium chloride and, and phthalic anhydride is obtained, N of increased amount of generated, and phthalic anhydride, dissolving the-dimethylformamide N, solid-liquid through separation of solid (chloro methylene) dimethyl ammonium chloride to obtain. the method number 1-step reaction through the interrupt input is an input from the data input sulfur dioxide, high vacuum under conditions protruded from sulfur dioxide and does not require the removal of, , moderating reaction conditions, to implemented very easily in.
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Paragraph 0021-0023
(2016/12/22)
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- Syntheses of 4-substituted 2-(trichloromethyl)quinazolines under mild conditions by benzyne [4+2] cycloaddition
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An experimentally simple and convenient synthesis of 4-susbstituted 2-(trichloromethyl)quinazolines by cycloaddition of benzyne with 2-(trichloromethyl)-1,3-diazabutadienes was developed. The 2-(trichloromethyl)-1,3-diazabutadienes (R1 = H and Me) were prepared from trichloroacetamidine and the appropriate N,N-dimethylamide dimethyl acetal or from trichloroacetamidine and a Vilsmeier-Haack reagent containing an aryl group.
- Lechuga-Eduardo, Harim,Olivo, Horacio F.,Romero-Ortega, Moises
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p. 5910 - 5913
(2015/03/30)
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- New preparation method for Vilsmeier reagent and related imidoyl chlorides
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An environmentally benign and inexpensive preparation method is described of some imidoyl chlorides, including the Vilsmeier reagent (VR), by using phthaloyl dichloride. Synthetic applications were demonstrated using the isolated VR or VR prepared in situ for the transformation of acids to acid chlorides, alcohols to chlorides, and the formylation of dimethylaminobenzene.
- Kimura, Yoshikazu,Matsuura, Daisuke,Hanawa, Takeshi,Kobayashi, Yukimoto
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experimental part
p. 1116 - 1118
(2012/03/26)
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- Stereoselective control in the Staudinger reactions involving monosubstituted ketenes with electron acceptor substituents: Experimental investigation and theoretical rationalization
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The stereoselectivity of the Staudinger reactions involving monosubstituted ketenes with electron acceptor substituents was investigated experimentally by determination of the product stereochemistry and theoretically via DFT calculations. The results indicate that imines preferentially attack the less sterically hindered exo-side of the ketenes to generate zwitterionic intermediates. Subsequently, for cyclic imines, the intermediates undergo a conrotatory ring closure directly to produce β-lactams, while for linear imines, the imine moiety of the intermediates isomerizes to more stable intermediates, which further undergo a conrotatory ring closure to afford trans-β-lactams. The steric hindrance and the isomerization, rather than the torquoelectronic effect, play crucial roles in controlling the stereoselectivity in the practical Staudinger reactions involving monosubstituted ketenes with electron acceptor substituents, although the unaccessible borylketene with a powerful electron acceptor group controls the stereoselectivity torquoelectronically, in theory.
- Qi, Hengzhen,Li, Xinyao,Xu, Jiaxi
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supporting information; experimental part
p. 2702 - 2714
(2011/05/19)
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- New Vilsmeier reaction for facile synthesis of 4-phenyl-2,4- dihydrochromeno[4,3-c]pyrazoles with Bis(trichloromethyl) carbonate/DMF
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An efficient method for the synthesis of 4-phenyl-2,4-dihydrochromeno[4,3- c]pyrazoles via the cyclisation reaction of the easily available flavanone-4-arylhydrazones with Vilsmeier reagent (Bis(trichloromethyl) carbonate/DMF) has been developed.
- Chen, Zhiwei,Yang, Yanyan,Su, Weike
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experimental part
p. 661 - 664
(2011/03/18)
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- Diastereoselective total synthesis of 8-epigrosheimin
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The first diastereoselective total synthesis of 8-epigrosheimin was accomplished relying entirely on substrate-controlled methods. 8-Epigrosheimin, isolated as an amoebicidal and antibiotic compound from Crepis virens, is a multi-chiral-centered guaianolide with a cis-hydroazulene and a trans-annulated γ-butyrolactone ring. Our approach featured that the γ-butyrolactone unit was formed firstly before the construction of the cycloheptane ring system. The key steps of the synthesis involved (1) a stereoselective Mukaiyama aldol addition; (2) an oxidative γ-lactonization; and (3) an intramolecular aldehyde-ene cyclization.
- Yang, Haishen,Qiao, Xiaoxiao,Li, Fangyi,Ma, Hui,Xie, Longguan,Xu, Xiaohua
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supporting information; experimental part
p. 1110 - 1112
(2009/05/27)
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- Highly planar amphiphilic porphyrins
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A first synthesis of an asymmetric and amphiphilic β-substituted porphyrin is reported. The porphyrin can be integrated into various types of nanostructures with the amphiphilic characters in hydrophilic solvents. The one-dimensional integration may induc
- Oda, Masafumi,Ishizuka, Tomoya,Arai, Shigeo,Takano, Atsushi,Jiang, Donglin
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supporting information; experimental part
p. 7137 - 7140
(2010/02/27)
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- Generation of Phosphorus Oxychloride as by-Product from Phosphorus Pentachloride and DMF and its Use for Chlorination Reaction by Converting Into Vilsmeier-Haack Reagent
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A process is described wherein after formation of first crop of Vilsmeier-Haack reagent by reacting Phosphorus Pentachloride with N,N-dimethylformamide to form a first crop of Vilsmeier reagent as insoluble crystals, a by-product of this reaction, the Phosphorus Oxy-Chloride, reacts with N,N-dimethylformamide to give a second crop of Vilsmeier reagent. This second crop of Vilsmeier reagent is soluble in DMF. This process makes it possible to double the yield of chlorinated substrate, such as sucrose-6-acetate or sucrose-6-benzoate, from the same quantity of Phosphorus Pentachloride.
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Page/Page column title page; 2-3; Fig.1
(2009/05/28)
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- Simple synthesis of 4-substituted 1(2H)-isoquinolinones via electrophilic trapping of lithiated mono- and dianion precursors
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Synthetic routes have been developed to access 4-substituted 1(2H)-isoquinolinones from readily available precursors. This is achieved via electrophilic trapping of di- and monolithium anions derived from alkyllithium exchange of 4-bromo-1(2H)-isoquinolinones and corresponding 4-bromo-1- methoxyisoquinolines, respectively. Products derived from the latter are then hydrolyzed to the target 4-substituted 1(2H)-isoquinolinones. The methodology has potential application to access 4-substituted 1(2H)-isoquinolinones with additional substituents in either ring. Copyright Taylor & Francis Group, LLC.
- Sercel, Anthony D.,Sanchez, Joseph P.,Showalter, H. D. Hollis
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p. 4199 - 4208
(2008/03/13)
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- Protected aminothiazolylacetic acid derivatives
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Described is a protected aminothiazolylacetic acid derivative represented by the following formula (I): STR1 wherein A represents a nitrogen atom or a methine group, R1 and R2 may be the same or different and individually represent a hydrogen atom, a lower alkyl group or a substituted or unsubstituted aryl group, R3 represents a lower alkoxy group, a halogenated lower alkoxy group, a triphenylmethoxy group, a lower alkyl group or an acyloxy group, and R4 represents a halogen atom, a hydroxy group, a lower alkoxy group or a substituted or unsubstituted amino group; and salts thereof; as well as processes for the preparation thereof. The protected aminothaizolylacetic acid derivative according to the present invention is an useful intermediate for introducing a 2-(2-aminothiazol-4-yl)-2-alkoxyiminoacetyl group or a 2-(2-aminotiazol-4-yl)-2-alkenoyl group into a cephem skeleton.
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- Cephalosporin derivatives
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A cephalosporin derivative of the formula I: STR1 in which X is STR2 represents one of C-7 acyl groups known in the cephalosporin art, R3 is hydrogen or methoxy, R4 is hydrogen, optionally substituted alkyl or allyl, and R5 is an aromatic heterocyclic ring system which is linked via carbon, and which contains a quaternized nitrogen atom.
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- Cephalosporin derivatives
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According to the invention there is provided a antibacterial cephalosporin derivative of the formula: STR1 in which X is sulphur, oxygen, methylene or sulphinyl; R3 is hydrogen or methoxy; R1 and R2 are known in the cephalosporin art and R4 is an aminomethyl group in which the amino group carries one of various positively charged nitrogen-containing species set out in the specification and optionally a further substituent selected from hydrogen, lower alkyl, benzyl or heteroarylloweralkyl groups.
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- Reagents and Synthetic Methods. Part 58. Synthesis of β-Lactams from Acetic Acids and Imines promoted by Vilsmeier Type Reagents
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The development of a practical method for the stereospecific preparation of several 3-substituted β-lactams from acetic acids and imines is described.The key step of the method is the activation of the carboxy component by means of Vilsmeier type reagents.The preparation of some N-(2'-hydroxyethyl)-β-lactams and N-(p-dimethyl-t-butylsiloxyphenyl)-β-lactams as intermediates for N-H azetidinones is also reported.For the last compounds the steric bulk of the N-substituent is the key feature for a high cis-β-lactam formation.
- Arrieta, Ana,Lecea, Begona,Palomo, Claudio
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p. 845 - 850
(2007/10/02)
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- 3-substituted-aminomethyl cephalosporin derivatives
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A cephalosporin derivative of the formula I: STR1 in which X is S, O, CH2 or SO, R1 is (optionally-substituted)imidazol-2-yl or one of the C-7 acyl groups known in the cephalosporin art, R2 is hydrogen or methoxy, R3 is carboxy or a biodegradable ester thereof and --R4 is of the formula XII, XIII or XIV: STR2 in which R32-R40 inclusive are as defined in the specification; and the salts thereof. Pharmaceutical compositions, methods of manufacture and intermediates are also described.
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- NEW REACTIONS OF 4,5-DICHLORO-2-DICHLOROMETHYLENE-4-CYCLOPENTENE-1,3-DIONE
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The reaction of 4,5-dichloro-2-dichloromethylene-4-cyclopentene-1,3-dione with DMFA gives a high yield of 2,3-dichloro-5-(dimethyliminiomethyl)-2-cyclopentene-1,4-dione. 2,3-Dichloro-5,5-bismethylthio-2-cyclopentene-1,4-dione was isolated as a result of the analogous reaction with DMSO.A reaction mechanism involving diketocarbene is proposed.
- Gunbin, V. N.,Talzi, V. P.,Gudoshnikov, S. K.,Barysheva, N. A.,Maslennikov, E. I.
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p. 465 - 468
(2007/10/02)
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- Process for the preparation of 4,1',6'-trichloro-4,1',6'-trideoxygalactosucrose
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4,1',6'-trichloro-4,1',6'-trideoxygalactosucrose is prepared by a process including the steps of: (a) isomerizing 2,3,4,3',4'-penta-O-acetyl sucrose to 2,3,6,3',4'-penta-O-acetyl sucrose; (b) chlorinating the isomerized acetate at the 4,1' and 6'-positions; and (c) deacetylating the resulting chlorinated product; the isomerization step (a) being effected by treating a solution of 2,3,4,3',4'-penta-O-acetyl sucrose in an inert solvent with a weak acid at an elevated temperature.
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- Convenient Syntheses of 5-Substituted 2-Hydroxybenzoates and Related Reactions
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The enamine aldehydes RC(=CHNMe2)CHO (R = Et or Ph) were condensed with the bis-enolate CH2=C-(O-)CH=C(O-)OEt to give the title aromatic compounds.Thus these products are available from the acetals R1CH2CH(OR2)2 (R1 = R2 = Et; R1 = Ph, R2 =Me) in two steps.The Vilsmeier formylation of the several derivatives of butanal was examined.
- Barton, Derek H. R.,Dressaire, Gilles,Willis, Brian J.,Barrett, Anthony G.M.,Pfeffer, Marc
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p. 665 - 670
(2007/10/02)
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- Process for the chlorination of α-aminoacids
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A process for the chlorination of the carboxylic group of α-aminoacids is described whereby an aminoacid (e.g. p-hydroxy-phenyl-glycine) is suspended in an anhydrous solvent such as dioxane and treated with a chlorinating agent of the formula: STR1 in the presence of HCl in excess. The preferred chlorinating agent is chloromethylene-dimethylammonium chloride.
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- Pyridyl substituted 7-αesters of 3 heterothio 7-acetamido cephalosporanic acids
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This invention relates to new cephalosporanic acid derivatives and pharmaceutically acceptable salts thereof which possess antibacterial activity, pharmaceutical composition of the same and processes for the preparation thereof.
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