cas 18584-20-8, HYDROXY-P-TOLYL-ACETIC ACID

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Reductive Coupling of Carbon Dioxide and an Aldehyde Mediated by a Copper(I) Complex toward the Synthesis of α-Hydroxycarboxylic Acids
Copper-mediated reductive coupling between CO2 and an aldehyde to form α-hydroxycarboxylic acid was achieved using silylborane as a reductant. CO2 cleanly inserted into a copper-carbon bond that was formed by the reaction between a silylcopper-NHC complex
Masada, Koichiro,Kusumoto, Shuhei,Nozaki, Kyoko
p. 4922 - 4926
(2020)
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Highly Efficient Deracemization of Racemic 2-Hydroxy Acids in a Three-Enzyme Co-Expression System Using a Novel Ketoacid Reductase
Enantiopure 2-hydroxy acids (2-HAs) are important intermediates for the synthesis of pharmaceuticals and fine chemicals. Deracemization of racemic 2-HAs into the corresponding single enantiomers represents an economical and highly efficient approach for synthesizing chiral 2-HAs in industry. In this work, a novel ketoacid reductase from Leuconostoc lactis (LlKAR) with higher activity and substrate tolerance towards aromatic α-ketoacids was discovered by genome mining, and then its enzymatic properties were characterized. Accordingly, an engineered Escherichia coli (HADH-LlKAR-GDH) co-expressing 2-hydroxyacid dehydrogenase, LlKAR, and glucose dehydrogenase was constructed for efficient deracemization of racemic 2-HAs. Most of the racemic 2-HAs were deracemized to their (R)-isomers at high yields and enantiomeric purity. In the case of racemic 2-chloromandelic acid, as much as 300 mM of substrate was completely transformed into the optically pure (R)-2-chloromandelic acid (> 99% enantiomeric excess) with a high productivity of 83.8 g L?1 day?1 without addition of exogenous cofactor, which make this novel whole-cell biocatalyst more promising and competitive in practical application.
Xue, Ya-Ping,Wang, Chuang,Wang, Di-Chen,Liu, Zhi-Qiang,Zheng, Yu-Guo
p. 1 - 13
(2018/04/26)

The Synthesis of Chiral α-Aryl α-Hydroxy Carboxylic Acids via RuPHOX-Ru Catalyzed Asymmetric Hydrogenation
A ruthenocenyl phosphino-oxazoline-ruthenium complex (RuPHOX?Ru) catalyzed asymmetric hydrogenation of α-aryl keto acids has been successfully developed, affording the corresponding chiral α-aryl α-hydroxy carboxylic acids in high yields and with up to 97% ee. The reaction could be performed on a gram scale with a relatively low catalyst loading (up to 5000 S/C) and the resulting products can be transformed to several chiral building blocks, biologically active compounds and chiral drugs. (Figure presented.).
Guo, Huan,Li, Jing,Liu, Delong,Zhang, Wanbin
p. 3665 - 3673
(2017/09/11)

Chemoenzymatic Preparation of Enantiomerically Enriched (R)-(–)-Mandelic Acid Derivatives: Application in the Synthesis of the Active Agent Pemoline
The enantioselective resolution of several racemic derivatives of mandelic acid methyl ester catalyzed by lipases from Pseudomonas fluorescens (Amano AK) or Burkholderia cepacia (Amano PS-C II and Amano PS-IM) has been achieved. A gram-scale lipase-mediated kinetic resolution approach has been developed that allows the facile synthesis of the corresponding methyl (R)-(–)-mandelates with excellent enantiomeric excesses (up to >99 % ee) and reaction enantioselectivity (E values up to >200). The dopaminergic agent pemoline, used in the treatment of attention-deficit hyperactivity disorder (ADHD) and narcolepsy, was synthesized with 98 % ee in a straightforward route by condensing the prepared methyl (R)-(–)-mandelate with guanidine hydrochloride under basic conditions. The desired (R)-(+)-pemoline in optically pure form (>99 % ee) was obtained after two recrystallizations from ethanol. However, it was confirmed by chiral HPLC that optically active pemoline undergoes racemization in methanol solution.
Potera?a, Marcin,Dranka, Maciej,Borowiecki, Pawe?
p. 2290 - 2304
(2017/05/01)

Silica sulfuric acid as a highly efficient catalyst for the synthesis of diarylacetic acids
ABSTRACT: An efficient heterogeneous method for the synthesis of diarylacetic acids was developed utilizing silica sulfuric acid as a catalyst. The reaction is highly efficient with a small amount of catalyst for the combination of a variety of electron-n
Moore, Desiree L.,Denton, Allison E.,Kohinke, Rose M.,Craig, Brandon R.,Brenzovich, William E.
supporting information
p. 604 - 612
(2016/07/06)

Asymmetric hydrogenation reaction of alpha-ketoacids compound
The invention relates to the technical field of organic chemistry, especially to an asymmetric hydrogenation reaction of an alpha-ketoacids compound. The asymmetric hydrogenation reaction comprises a scheme shown in the description. In the scheme, R1 is phenyl, substituted phenyl, naphthyl, substituted naphthyl, C1-C6 alkyl, or aralkyl; a substituent group is C1-C6 alkyl, C1-C6 alkoxy, or halogen; and the number of the substituent group is 1-3. In the scheme, M is a chiral spiro-pyridylamino phosphine ligand iridium complex having a structure shown in the description. In the structure, R is hydrogen, 3-methyl, 4-tBu, or 6-methyl.
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Paragraph 0031; 0032; 0033; 0037

(2016/10/10)

Solid phase behavior in the chiral systems of various 2-hydroxy-2-phenylacetic acid (mandelic acid) derivatives
The solid phase behavior of a series of monosubstituted F-, Cl-, Br-, I-, and CH3- and two 2,4-halogen-disubstituted 2-hydroxy-2-phenylacetic acid (mandelic acid) derivatives was investigated. The study includes detailed information about melting temperature, melting enthalpy, X-ray diffraction data, as well as selected binary phase diagrams of the respective chiral systems. Aside from the known metastable conglomerate 2-chloromandelic acid, evidence for two more metastable conglomerates was found.
Von Langermann, Jan,Temmel, Erik,Seidel-Morgenstern, Andreas,Lorenz, Heike
p. 721 - 728
(2015/03/30)

Carboxylation with CO2 via brook rearrangement: Preparation of α-hydroxy acid derivatives
In the presence of CsF, a wide range of α-substituted α-siloxy silanes were carboxylated under a CO2 atmosphere (1 atm) via Brook rearrangement. A variety of α-substituents including aryl, alkenyl, and alkyl groups were tolerated to afford α-hydroxy acids in moderate-to-high yields. One-pot synthesis from aldehydes using PhMe2SiLi and CO 2 was also possible, providing α-hydroxy acids without the isolation of an α-hydroxy silane.
Mita, Tsuyoshi,Higuchi, Yuki,Sato, Yoshihiro
p. 14 - 17
(2014/01/23)

Kinetic resolution of mandelate esters via stereoselective acylation catalyzed by lipase PS-30
By using lipase PS-30 as catalyst, the kinetic resolution of a series of racemic mandelate esters has been achieved via stereoselective acylation. The value of kinetic enantiomeric ratio (E) reached up to 197.5. Substituent effect is briefly discussed.
Chen, Peiran,Yang, Wenhong
p. 2290 - 2294
(2014/04/17)

Relationships between the racemic structures of substituted mandelic acids containing 8- and 10-membered hydrogen bonded dimer rings
The structures of 27 monosubstituted mandelic acids, including several of their polymorphs, plus unsubstituted mandelic acid itself (two polymorphs) are investigated for structural similarity. The results, presented pictorially as a structural relationship plot, show that rather more structures are built up from the carboxyl-chain hydroxyl hydrogen bonded dimer than from the conventional carboxylic acid dimer. The results show how all the structures are related and, based on the two types of dimer, the degree of similarity that they possess. Some structures with Z′ > 1 contain both sorts of dimers and there are many examples of isostructural sets within the structures so far determined. We also present an example where analysing similarity in related families of structures highlights a structure that should be present and which has indeed then proceeded to be synthesised and determined.
Coles,Ellis,Leung,Sarson,Threlfall,Tizzard
p. 10816 - 10823
(2015/02/19)

A chemoselective oxidation of monosubstituted ethylene glycol: Facile synthesis of optically active α-hydroxy acids
A mild and efficient method for the synthesis of optically active α-hydroxy acids through chemoselective oxidation of monosubstituted ethylene glycols using the TEMPO-NaOCl reagent system is described. It is evident from our studies that the solvent, pH and reaction temperature are very crucial for the success of this oxidation. The versatility of this method has been demonstrated with a variety of aliphatic, aromatic and carbohydrate substrates bearing various functional groups. the Partner Organisations 2014.
Chinthapally, Kiran,Baskaran, Sundarababu
supporting information
p. 4305 - 4309
(2014/06/23)

Direct asymmetric hydrogenation of α-keto acids by using the highly efficient chiral spiro iridium catalysts
A new efficient and highly enantioselective direct asymmetric hydrogenation of α-keto acids employing the Ir/SpiroPAP catalyst under mild reaction conditions has been developed. This method might be feasible for the preparation of a series of chiral α-hydroxy acids on a large scale.
Yan, Pu-Cha,Xie, Jian-Hua,Zhang, Xiang-Dong,Chen, Kang,Li, Yuan-Qiang,Zhou, Qi-Lin,Che, Da-Qing
p. 15987 - 15990
(2015/02/19)

One-pot, single-step deracemization of 2-hydroxyacids by tandem biocatalytic oxidation and reduction
A facile and efficient one-pot, single-step method for deracemizing a broad range of 2-hydroxyacids to (R)-2-hydroxyacids was established by combination of resting cells of an (S)-hydroxyacid dehydrogenase-producing microorganism and an (R)-ketoacid reductase-producing microorganism.
Xue, Ya-Ping,Zheng, Yu-Guo,Zhang, Ya-Qin,Sun, Jing-Lei,Liu, Zhi-Qiang,Shen, Yin-Chu
supporting information
p. 10706 - 10708
(2013/11/06)

The preparation of various new heterocyclic compounds via cyclization of substituted derivatives of phenacyl esters of hydrazonoacetic acid
A procedure for the preparation of derivatives of phenacyl hydrazonopropanoates and their application in the synthesis of various heterocycles has been developed. Not only is the preparation of indole derivatives described, but also a new method for the preparation of previously unknown pyridazine derivatives.
Melnicky, Radek,Grepl, Martin,Lycka, Antonin,Bertolasi, Valerio,Kvapil, Lubomir,Dvorakova, Barbora,Hradil, Pavel
p. 2447 - 2457
(2013/09/23)

Amberlyst A-26: An efficient and reusable heterogeneous catalyst for a one-pot oxidation-Cannizarro reaction
Amberlyst A-26 catalyses the efficient synthesis of α-hydroxy- arylacetic acids from aryl methyl ketones in the presence of SeO2. After simple separation, the catalyst does not lose its activity and can be reused without significant loss in activity for at least four cycles.
Shen, Ming-Gui,Shang, Shi-Bin,Song, Zhan-Qian,Wang, Dan,Rao, Xiao-Ping,Gao, Hong,Liu, He
p. 51 - 52
(2013/03/29)

Robust enzymatic resolution of 3-fluoromandelic acid with lipase PS supported on celite
The resolution of different mandelic acids using the lipase PS Amano SD enzyme is described. By supporting the lyophilized enzyme over Celite, both the activity and the stability of lipase PS in organic media were significantly improved, enabling the robust resolution scale-up of 3-fluoromandelic acid. The methodology was extended to produce a range of optically pure (R)-mandelic acids, avoiding tedious extractions or chromatography.
Mendiola, Javier,Garcia-Cerrada, Susana,De Frutos, Oscar,De La Puente, Maria Luz
experimental part
p. 1312 - 1316
(2012/10/18)

A rapid and green approach to chiral α-hydroxy esters: asymmetric transfer hydrogenation (ATH) of α-keto esters in water by use of surfactants
A series of α-hydroxy esters were rapidly prepared (1.5 h) from α-keto esters via asymmetric transfer hydrogenation (ATH) in water by the use of surfactants for the first time. This green method, catalyzed by a water-soluble and recyclable Ru(II) complex, gave moderate to high enantioselectivities (up to 99.7% ee) with DTAB as an additive and HCOONa as the hydrogen source.
Yin, Lu,Jia, Xian,Li, Xingshu,Chan, Albert S.C.
experimental part
p. 2033 - 2037
(2010/01/16)

Hydrogen-bonding sheets in crystals for chirality recognition: synthesis and application of (2S,3S)-2,3-dihydroxy- and (2S,3S)-2,3-dibenzyloxy-1,4-bis(hydroxyamino)butanes
Two enantiopure bis(hydroxyamino) compounds were successfully prepared from dialkyl tartrate by a chiral-pool method and applied as basic resolving agents in the enantioseparation of 2-arylpropanoic acids and arylglycolic acids. (2S,3S)-2,3-Dihydroxy-1,4-bis(hydroxyamino)butane (2S,3S)-1a could moderately recognize the chirality of the 2-arylpropanoic acids, while (2S,3S)-2,3-dibenzyloxy-1,4-bis(hydroxyamino)butane (2S,3S)-1b could not due to the low crystallinity of both the corresponding diastereomeric salts. On the other hand, (2S,3S)-1b showed a similar chirality-recognition ability for the arylglycolic acids. The ability of (2S,3S)-1b was different from those generally observed for widely used primary amine-type resolving agents with regard to the relationship between the resolution efficiency and the similarity in the relative molecular length of a resolving agent and a target racemate. The X-ray crystallographic analyses of the less-soluble diastereomeric salts revealed that in the salts (2S,3S)-1a formed a supramolecular sheet, of which the distance was variable to make the resultant dissymmetric space fit to the shape of the target acids, and that (2S,3S)-1b was constructed from a robust supramolecular sheet, consisting of hydrogen-bonding 21 columns, with the participation of the hydroxy group of the arylglycolic acids. These X-ray crystallographic analyses also suggested that for the formation of a supramolecular sheet, the coexistence of two hydroxyamino groups is essential.
Kobayashi, Yuka,Kokubo, Yasushi,Aisaka, Takamitsu,Saigo, Kazuhiko
scheme or table
p. 2536 - 2541
(2009/04/11)

Ytterbium triflate-promoted tandem one-pot oxidation-cannizzaro reaction of aryl methyl ketones
(Chemical Equation Presented) Ytterbium triflate was shown to be an effective catalyst in promoting the synthesis of either isopropyl esters or free α-hydroxy-arylacetic acids from substituted aromatic glyoxals and aryl methyl ketones, respectively. The reaction to provide acids starting from differently substituted ketones was carried out by an environmentally friendly method using an aqueous medium as a solvent and giving the adducts in 78-99% yield without any further purification after the usual workup.
Curini, Massimo,Epifano, Francesco,Genovese, Salvatore,Marcotullio, M. Carla,Rosati, Ornelio
p. 1331 - 1333
(2007/10/03)

Polymorphs of bicifadine hydrochloride
A new polymorphic crystalline form of bicifadine hydrochloride, designated form B, which is more thermodynamically stable than the previously known polymorphic form of bicifadine hydrochloride, designated as form A, methods for preparing said crystalline
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(2008/06/13)

Lipase-catalyzed enantioselective transesterification toward esters of 2-bromo-tolylacetic acids
Lipases from Candida antarctica, Pseudomonas cepacia and Rhizomucor miehei were tested in the resolution of seven racemic substrates belonging to the (RS)-2-bromo tolyl acetate ester category, but differing either in the position of the methyl substituent on the acyl part of the aromatic ring, or in the structure of the alkyl group. Lipase-catalyzed kinetic resolution via transesterification reaction between the ester and octanol in octane revealed that, of the three enzymes tested, P. cepacia lipase is the most efficient for resolution of the various racemates, with R-enantiopreference. In addition, the position of the methyl substituent was found to play a key role in governing the enantioselectivity of the reaction. Using P. cepacia lipase and 2-bromo-m/p-tolyl- or 2-bromophenylacetic acid esters E-values of 6.
Guieysse, David,Salagnad, Christophe,Monsan, Pierre,Remaud-Simeon, Magali
p. 317 - 323
(2007/10/03)

Simple syntheses of hydroxamic acids and their conversion into α- hydroxy and α-amino acids
The nucleophilic ring opening of gem-dicyanoepoxides by LiBr or Li2NiBr4, in the presence of hydroxylamine derivatives leads to new α-halo hydroxamic acids. These compounds has been used in the synthesis of α- functionalized hydroxamic acids, α-hydroxy and α-amino acids in good yields.
Boukhris, Sa?d,Souizi, Abdelaziz
p. 2559 - 2562
(2007/10/03)

Reaction of carboxylic acids with diethyl phosphorocyanidate; a novel synthesis of homologated α-hydroxycarboxylic acids from carboxylic acids
Carboxylic acids react with 2 equivalents of diethyl phosphorocyanidate in the presence of triethylamine to give dicyanophosphates in good yields; these dicyanophosphates can be hydrolyzed easily to give homologated α- hydroxycarboxylic acids.
Mizuno, Masanori,Shioiri, Takayuki
p. 9209 - 9210
(2007/10/03)

Synthesis of Chiral α-Aryl-α-Hydroxyacetic Acids: Substituent Effects in Pig Liver Acetone Powder (PLAP) Induced Enantioselective Hydrolysis
Pig liver acetone powder (PLAP) catalyzed hydrolysis of alkyl α-acetoxy-α-arylacetates produces alkyl (S)-α-aryl-α-hydroxyacetates in 23-80percent enantiomeric purities.Enantioselectivity is dependent on the ester group of O-acetylmandelates.Substitution on the aromatic ring results in inferior selectivities.Only acetate group is hydrolyzed by PLAP while the ester functionality is found to be completely intact.
Basavaiah, Deevi,Krishna, Peddinti Rama
p. 2403 - 2416
(2007/10/02)

β-Cyclodextrin-teba: A new catalyst system for selective synthesis of α-hydroxyacids
The presence of β-cyclodextrin (β-CD) and triethylbenzyl ammonium chloride (TEBA) favors the one-pot reaction of aromatic aldehydes, chloroform and sodium hydroxide to give α- hydroxyarylacetic acids in 81% ~ 89% yields.
Zhou,Yuan,Xie
p. 43 - 46
(2007/10/02)

Reduction of manganate(VI) by mandelic acid and its significance to development of a general mechanism for oxidation of organic compounds by high-valent transition metal oxides
Results obtained from a study of the oxidation of mandelic acid and cyclobutanol by manganate(VI) indicate that reaction mechanisms traditionally applied to oxidations of this type (i.e., hydrogen atom or hydride ion transfers) may not be correct. Instead it appears that the reaction may be initiated by a 2 + 2 addition of the α-C-H bond to a manganese oxo double bond. This interpretation may be useful in the development of a general mechanism for the oxidation of organic compounds by high-valent transition metal oxides including more common oxidants such as permanganate, ruthenium tetroxide, and chromic acid.
Lee, Donald G.,Chen, Tao
p. 11231 - 11236
(2007/10/02)

Optically Active α-Acetoxycarboxylic Acids and α-Hydroxycarboxylic Acids by Enzyme-Aided Syntheses
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Jeromin, Guenter E.,Albertz, Michael
p. 526 - 528
(2007/10/02)

Optically Active Amines. 36. Application of the Benzene Chirality Rule to Ring-Substituted Mandelic Acids
The positive sign of the 1Lb Cotton effects (CEs) from about 250 to 270 nm in the circular dichroism (CD) spectrum of (R)-mandelic acid and its sodium salt is determined by vibronic borrowing from allowed transitions at shorter wavelength.On ring substitution, transition moments are induced in the benzene ring bonds adjacent to the attachment bond of the chiral group, resulting in enhanced coupling of the 1Lb transition with the chiral group.The sign of the 1Lb CEs for a ring-substituted (R)-mandelic acid may be the same or opposite to that of (R)-mandelic acid, but the sign of its 1Lb CEs can often be correlated wit h its absolute configuration provided the ring position of the substituent and its spectroscopic moment is taken into account.
Colon, Diana F.,Pickard, Simeon T.,Smith, Howard E.
p. 2322 - 2326
(2007/10/02)

The Oxidation of Alcohols by Permanganate. A Comparison with Other High-Valent Transition-Metal Oxidants
The results obtained from a study of the oxidation of mandelic acid and cyclobutanol by permanganate in 1.0 M KOH are best accomodated by a mechanism in which the initial reaction is the addition of a manganese-oxo bond to the α-C-H bond of the alcohol, followed by homolytic cleavage of the resulting Mn-C bond to give free-radical intermediates.A comparison with other high-valent transition-metal oxidants suggests that it is possible to systematically classify the way in which these reagents react with alcohols on the basis of the initial reaction (C-H or O-H addition) and the cleavage mode of the metal-oxygen or metal-carbon bond (homolytic or heterolytic).The approach provides a framework for understanding these reactions that is less chaotic than the current situation where distinctive mechanisms have been proposed for each individual oxidant.
Lee, Donald G.,Chen, Tao
p. 5341 - 5345
(2007/10/02)

A facile one-pot synthesis of α-hydroxy acids and their derivatives
2-Substituted oxirane-1,1-dicarbonitriles react with water, alcohols or phenol to give 2-substituted 2-hydroxyacetic acids, alkyl-2-alkoxyacetates and phenyl 2-phenoxyacetates, respectively. Reaction of 2-substituted oxirane-1,1-dicarbonitrile with thiophenol and a nucleophile, typically water ethanol or urea, gave 2-(phenylthio)acetic acids, ethyl 2-(phenylthio)acetates and N-aminocarbonyl-2-(phenylthio)acetamides.
Florac,Le Grel,Baudy-Floc'h,Robert
p. 741 - 743
(2007/10/02)

A Convenient Route to (R)-α-Hydroxy Carboxylic Acids and (2R)-1-Amino-2-alkanols from (R)-Cyanohydrins
(R)-Cyanohydrins, prepared in good to excellent yields with high optical purity by enzyme-catalyzed addition of hydrogen cyanide to aldehydes in organic solvents, are hydrolyzed with concentrated hydrochloric acid at ambient temperature, usually in very high yield, without any trace of racemization to give (R)-α-hydroxy carboxylic acids.Likewise, no racemization is observed by direct reduction of the (R)-cyanohydrins with lithium aluminium hydride to give (2R)-1-amino-2-alkanols.
Ziegler, Thomas,Hoersch, Brigitte,Effenberger, Franz
p. 575 - 578
(2007/10/02)

ENZYME-CATALYZED SYNTHESIS OF (S)-CYANOHYDRINS AND SUBSEQUENT HYDROLYSIS TO (S)-α-HYDROXY-CARBOXYLIC ACIDS
(S)-Cyanohydrins 2 are obtained with high enantioselectivity from aromatic aldehydes and HCN in the presence of (S)-oxynitrilase (E.C.4.1.2.11).Acid-catalyzed hydrolysis of the cyanohydrins 2 affords the corresponding (S)-α-hydroxy carboxylic acids 3 without racemization.
Effenberger, Franz,Hoersch, Brigitte,Foerster, Siegfried,Ziegler, Thomas
p. 1249 - 1252
(2007/10/02)

Tris(benzotriazol-1-yl)methane: A -CO2H Synthon for the Preparation of Carboxylic Acids
Lithiation of tris(benzotriazol-1-yl)methane 16 gives the tris(benzotriazolyl)methyl carbanion 17 which affords substitution products 18 with many electrophiles.Acidic hydrolysis of 18 affords the corresponding carboxylic acids 19 in good yield.The syntheses of several α-functionalized carboxylic acids are described.
Katritzky, Alan R.,Yang, Zhijun,Lam, Jamshed N.
p. 666 - 669
(2007/10/02)

N-(1-ARYL-2,2,2-TRIHALOGENOETHYL)CARBOXAMIDES
The readily obtained products from the condensation of trihalogenoacetaldehydes with carboxamides react with benzene and its homologs in the presence of concentrated sulfuric acid with the formation of N-(1-aryl-2,2,2-trihalogenoethyl)carboxamides.The latter were used for the production of 1-aryl-2,2,2-trihalogenoethylamines and 1-acylimino-1-aryl-2,2,2-trihalogenoethanes.
Bal'on, Ya. G.,Smirnov, V. A.
p. 2051 - 2054
(2007/10/02)

SYNTHESIS AND SOME PROPERTIES OF 1,1-DI(ALKOXYCARBONYLAMINO)-2,2-DIHALOGENO- AND 1,1-DI(ALKOXYCARBONYLAMINO)-2,2,2-TRIHALOGENOETHANES
1,1-Di(alkoxycarbonylamino)-2,2,2-trihalogenoethanes were obtained by heating trihalogenoacetaldehydes or their hydrates with urethanes in a ratio of 1:2 in the presence of catalytic amounts of concentrated sulfuric acid.The products were reduced selectively with aluminum amalgam in 90percent alcohol to 1,1-di(alkoxycarbonylamino)-2,2-dihalogenoethanes.Compounds of both types react smoothly with benzene and its homologs in the presence of concentrated sulfuric acid and give 1-alkoxycarbonylamino-1-aryl-2,2-dihalogeno- and 1-alkoxycarbonylamino-1-aryl-2,2,2-trihalogenoethanes respectively.In an alkaline medium the latter are cleaved to aryloxyacetic acid, and with phosphorus pentachloride they form 1-aryl-2,2-dihalogeno- and 1-aryl-2,2,2-trihalogenoethyl isocyanates.
Bal'on, Ya. G.,Smirnov, V. A.
p. 2249 - 2254
(2007/10/02)

SYNTHESE EN UNE ETAPE D'α-ALCOXYHYDRAZIDES, DE DERIVES D'α-AMINOACIDES ET D'α-HYDROXYACIDES A PARTIR DES α-HALOGENOHYDRAZIDES. ETUDE DU MECANISME DE LA REACTION.
α-Halohydrazides react with nucleophiles under basic conditions to give α-functionalized hydrazides.We have shown that this reaction is not a direct nucleophilic substitution of the halogen but more likely proceeds through the formation of an aziridinone
Legrel, P.,Baudy-Floc'h, M.,Robert, A.
p. 4805 - 4814
(2007/10/02)

Cobalt-Catalyzed Normal Pressure Carbonylation of Aryl Halides. Notable Solvent Effects on the Ratio of Mono- to Double-Carbonylation
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Miura, Masahiro,Akase, Fumiaki,Nomura, Masakatsu
p. 2623 - 2625
(2007/10/02)

ONE-STEP SYNTHESIS OF α-HYDROXY ACIDS VIA REDUCTIVE DOUBLE CARBONYLATION OF ORGANIC HALIDES
Palladium-catalyzed carbonylation of organic halides with water in the presence of calcium hydroxide or lithium hydroxide in primary or secondary alcoholic solvents afforded α-hydroxy acids.
Kobayashi, Toshi-aki,Sakakura, Toshiyasu,Tanaka, Masato
p. 2721 - 2722
(2007/10/02)

SYNTHETIC METHODS BASED ON HALOGENOMAGNESIUM ALCOHOLATES. X. REACTIONS OF LITHIUM AND HALOGENOMAGNESIUM ALCOHOLATES WITH CHLORINATED ETHERS
The reaction of α-chlorinated ethers with lithium and halogenomagnesium alcoholates were investigated.Depending on the character of the radicals contained in the alcoholates, either alkoxymethyl derivatives of the enolic form of α-keto esters or the same derivatives of α-hydroxy esters are formed.
Kashinskii, V. N.,Demanov, V. A.,Lapkin, I.I.
p. 72 - 75
(2007/10/02)

Mechanism of Hydrolysis of Hydroxy Thiolesters in the Presence of Boric Acid
The catalytic effect of boric acid on the hydrolysis of S-butyl 2-hydroxy-2-phenylthioacetate (thiomandelate, 1) and 3-hydroxy-3-phenylthiopropionate (2) has been investigated in aqueous solution.The catalytic constants increased sigmoidally with increasing pH, the pKa of the curve being 9.2 for both 1 and 2.Approximate Hammett ρ values were 1.2 and 0.6 for the alkaline and borate-catalyzed hydrolyses of ring-substituted derivatives of 1, respectively.Boric acid did not show any specific influence on the hydrazinolysis of 1.Thise results lead to the conclusion that the borate catalysis occurs through an intramolecular transfer of the boron-coordinated hydroxide ion to the carbonyl carbon within a borate-substrate complex.
Okuyama, Tadashi,Nagamatsu, Hiroaki,Fueno, Takayuki
p. 1336 - 1342
(2007/10/02)

HYPERVALENT IODINE IN ORGANIC SYNTHESIS. A NEW ROUTE TO α-FUNCTIONALIZED CARBOXYLATE ESTERS.
Aryl and alkylcarboxylate esters are converted into the corresponding α-hydroxy acids or α-alkoxyesters upon treatment with C6H5I(OAc)2 and base in the appropriate solvent.
Moriarty, Robert M.,Hu, Henry
p. 2747 - 2750
(2007/10/02)

7-α-Amino-substituted acylamino-3-(1-carboxymethyltetrazol-5-ylthiomethyl)-3-cephem-4-carboxylic acids
Certain 7-acylamido-3-(1-carboxy-loweralkyl-tetrazol-5-ylthiomethyl)-3-cephem-4-carboxylic acids and their salts and easily hydrolyzed esters of the 4-carboxyl group were synthesized and found to be potent antibacterial agents which exhibited good aqueous solubility. In a preferred embodiment the 7-substituent was 2'-aminomethylphenylacetamido.
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(2008/06/13)

Studies on the rearrangement of (trichloromethyl)carbinols to α-chloroacetic acids
Phenyl(trichloromethyl)carbinol undergoes an unimolecular, predominantly intramolecular conversion into potassium α-chlorophenylacetate on stirring with 10percent aqueous potassium hydroxide at 0 deg C for several days.Besides providing an interesting example of a 1-2 chlorine shift, the reaction is of potential importance for the synthesis of α-chloro acids.The study of a variety of (trichloromethyl)carbinols shows the reaction is general for secondary (trichloromethyl)carbinols as well as trichloroethanol.The mechanism of the reaction involves the preliminary formation of an epoxide.Several mechanisms are considered for the conversion of the epoxide to the α-chloroacetate anion, but none accounts for all of the experimental facts.Tertiary carbinols break down at the epoxide stage into a ketone and carbon monoxide.
Reeve, Wilkins,McKee, James R.,Brown, Robert,Lakshmanan, Sitarama,McKee, Gertrude A.
p. 485 - 493
(2007/10/02)

7-(D-α-Hydroxy-2-arylacetamido)-3-(2-carboxyalkyl-2,3-dihydro-s-triazolo-[4,3-b]pyridazin-3-on-6-ylthiomethyl)-3-cephem-4-carboxylic acids and derivatives
7-(D-α-Hydroxy-2-arylacetamido)-3-(2-carboxyalkyl-2,3-dihydro-s-triazolo[4,3-b]pyridazin-3-on-6-ylthiomethyl)-3-cephem-4-carboxylic acids and derivatives containing blocking groups on the α-hydroxy group and their nontoxic, pharmaceutically acceptable salts are valuable as antibacterial agents and are particularly valuable as therapeutic agents in poultry and in animals, including man, in the treatment of infectious diseases caused by many Gram-positive and Gram-negative bacteria. A preferred compound is 7-(D-mandelamido)-3-(2-carboxyalkyl-2,3-dihydro-s-triazolo[4,3-b]pyridazin-3-on-6-ylthiomethyl)-3-cephem-4-carboxylic acid.
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(2008/06/13)

7-(D-α-Hydroxy-2-arylacetamido)-3-(tetrazolo-[4,5-b]pyridazin-6-ylthiomethyl)-3-cephem-4-carboxylic acids
7-(D-α-Hydroxy-2-arylacetamido)-3-(tetrazolo-[4,5-b]pyridazin-6-ylthiomethyl)-3-cephem-4-carboxylic acids and their nontoxic, pharmaceutically acceptable salts are valuable as antibacterial agents and are particularly valuable as therapeutic agents in poultry and animals, including man, in the treatment of infectious diseases caused by many Gram-positive and Gram-negative bacteria.
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(2008/06/13)

Semisynthetic cephalosporins. Synthesis and structure activity relationships of 7 mandelamido 3 cephem 4 carboxylic acids
The synthesis, microbiological profile, and in vivo effectiveness in laboratory animals of a broad spectrum cephalosporin, 7(R) mandelamidocephalosporanic acid (1), are described. A number of derivatives and analogs of 1 were prepared and their structure activity relationships are discussed.
Hoover,Dunn,Jakas,Lam,Taggart,Guarini,Phillips
p. 34 - 41
(2007/10/06)