- Conversion of Aliphatic Amides into Amines with benzene. Scope of the Reaction
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The reagent benzene, PIFA, brings about the facile oxidative rearrangement of aliphatic amides to amines in mildly acidic (pH 1-3) mixed aqueous-organic solvents.Aromatic amines are further oxidized by the reagent and therefore cannot be prepared by this method.The rearrangement, which is in effect an "Hofmann rearrangement", occurs with complete retention of configuration in the migrating group, and the rate of the reaction follows approximately the migratory aptitudes of the migrating groups determined for other similar reactions.Isocyanates are intermediates in the rearrangement but are rapidly hydrolyzed to the product amines under the mildly acidic conditions.The acidic conditions protect the product amines from reacting with the isocyanate intermediates and forming ureas.The reaction is accelerated by addition of pyridine to a pH of approximately 3.The scope of the reaction is discussed.
- Loudon, G. Marc,Radhakrishna, A. S.,Almond, Merrick R.,Blodgett, James K.,Boutin, Raymond H.
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- Direct Preparation of Amides from Amine Hydrochloride Salts and Orthoesters: A Synthetic and Mechanistic Perspective
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The conversion of a wide range of primary and secondary aliphatic and a few arylamine hydrochloride salts to their corresponding acetamides with trimethyl orthoacetate is described. Mechanistic studies using NMR and gas chromatography-mass spectrometry techniques indicate these reactions proceed via an O-methylimidate intermediate that undergoes in situ demethylation by chloride, affording the corresponding acetamides. Synthetically, this reaction represents a practical, high-yielding protocol with a simple workup for the rapid conversion of amine hydrochloride salts to acetamides.
- Di Grandi, Martin J.,Bennett, Caitlin,Cagino, Kristen,Muccini, Arnold,Suraci, Corey,Saba, Shahrokh
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- Hydrazine-mediated reduction of nitro and azide functionalities catalyzed by highly active and reusable magnetic iron oxide nanocrystals
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Iron oxide (Fe3O4) nanocrystals generated in situ from an inexpensive and readily available iron source catalyze the reduction of nitroarenes to anilines with unparalleled efficiency. The procedure is chemoselective, avoids the use of precious metals, and can be applied under mild reflux conditions (65 or 80 C) or using sealed vessel microwave heating in an elevated temperature regime (150 C). Utilizing microwave conditions, a variety of functionalized anilines have been prepared in nearly quantitative yields within 2-8 min at 150 C, in a procedure also successfully applied to the reduction of aliphatic nitro compounds and azides. The iron oxide nanoparticles are generated in a colloidal form, resulting in homogeneous solutions suitable for continuous flow processing. Selected examples of anilines of industrial importance have been prepared in a continuous regime using this protocol.
- Cantillo, David,Moghaddam, Mojtaba Mirhosseini,Kappe, C. Oliver
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- Preventing thermolysis: Precursor design for volatile copper compounds
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A copper(i) iminopyrrolidinate was synthesized and evaluated by thermal gravimetric analysis (TGA), solution based 1H NMR studies and surface chemistry to determine its thermal stability and decomposition mechanism. Copper(i) tert-butyl-imino-2
- Coyle, Jason P.,Kurek, Agnieszka,Pallister, Peter J.,Sirianni, Eric R.,Yap, Glenn P. A.,Barry, Sean T.
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- Cyclic (Alkyl)(amino)carbene Ligand-Promoted Nitro Deoxygenative Hydroboration with Chromium Catalysis: Scope, Mechanism, and Applications
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Transition metal catalysis that utilizes N-heterocyclic carbenes as noninnocent ligands in promoting transformations has not been well studied. We report here a cyclic (alkyl)(amino)carbene (CAAC) ligand-promoted nitro deoxygenative hydroboration with cost-effective chromium catalysis. Using 1 mol % of CAAC-Cr precatalyst, the addition of HBpin to nitro scaffolds leads to deoxygenation, allowing for the retention of various reducible functionalities and the compatibility of sensitive groups toward hydroboration, thereby providing a mild, chemoselective, and facile strategy to form anilines, as well as heteroaryl and aliphatic amine derivatives, with broad scope and particularly high turnover numbers (up to 1.8 × 106). Mechanistic studies, based on theoretical calculations, indicate that the CAAC ligand plays an important role in promoting polarity reversal of hydride of HBpin; it serves as an H-shuttle to facilitate deoxygenative hydroboration. The preparation of several commercially available pharmaceuticals by means of this strategy highlights its potential application in medicinal chemistry.
- Zhao, Lixing,Hu, Chenyang,Cong, Xuefeng,Deng, Gongda,Liu, Liu Leo,Luo, Meiming,Zeng, Xiaoming
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supporting information
p. 1618 - 1629
(2021/01/25)
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- Green method for catalyzing reduction reaction of aliphatic nitro derivative
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The invention relates to a green method for catalyzing reduction reaction of aliphatic nitro derivatives. According to the method, non-transition metal compounds, namely triethyl boron and potassium tert-butoxide, are used as a catalytic system for the first time, an aliphatic nitro derivative and pinacolborane which is low in price and easy to obtain are catalyzed to be subjected to a reduction reaction under mild conditions, and an aliphatic amine hydrochloride product is synthesized after acidification with a hydrochloric acid aqueous solution. Compared with a traditional method, the method generally has the advantages that the catalyst is cheap and easy to obtain, operation is convenient, and reaction is safe. The selective reduction reaction of the aliphatic nitro derivative catalyzed by the non-transition metal catalyst and pinacol borane is realized for the first time, and the aliphatic amine hydrochloride product is synthesized through acidification treatment of the hydrochloric acid aqueous solution, so that a practical new reaction strategy is provided for laboratory preparation or industrial production.
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Paragraph 0005-0006; 0037-0040
(2021/07/31)
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- A catalytic version of hypervalent aryl-λ3-iodane-induced Hofmann rearrangement of primary carboxamides: Iodobenzene as an organocatalyst and m-chloroperbenzoic acid as a terminal oxidant
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The first catalytic version of hypervalent aryl-λ3- iodane-induced Hofmann rearrangement of primary carboxamides, which probably involves in situ generation of a tetracoordinated bis(aqua)(hydroxy)phenyl- λ3-iodane complex as an active oxidant from a catalytic amount of iodobenzene by the reaction with m-chloroperbenzoic acid in the presence of HBF4 in dichloromethane-water under mild conditions, was developed.
- Miyamoto, Kazunori,Sakai, Yuuta,Goda, Shunsuke,Ochiai, Masahito
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supporting information; experimental part
p. 982 - 984
(2012/02/04)
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- General multicomponent strategy for the synthesis of 2-Amino-l,4- diazaheterocycles: Scope, limitations, and utility
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Multicomponent reactions of primary 1,2- and 1,3-diamines with carbonyl compounds and isocyanides resulting in the formation of diverse 2-amino-l,4-diazaheterocycles are described. Lewis acids (LAs) promote the reactions effectively, and chlorotrimethylsi
- Kysil, Volodymyr,Khvat, Alexander,Tsirulnikov, Sergey,Tkachenko, Sergey,Williams, Caroline,Churakova, Marina,Ivachtchenko, Alexandre
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experimental part
p. 1525 - 1543
(2010/06/16)
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- Synthesis of indolylindolines mediated by t-BuNH2
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An improved synthesis of N1-carbomethoxylated indolylindolines 2 from 5-substituted indoles 1, by replacing the previously employed strong acids or toxic metals with t-BuNH2/MeOCOCl in CH2Cl2/H2O, is described.
- Suarez-Castillo, Oscar R.,Melendez-Rodriguez, Myriam,Morales-Garcia, Ana L.,Cano-Escudero, Indira C.,Contreras-Martinez, Yaneth M.A.,Morales-Rios, Martha S.,Joseph-Nathan, Pedro
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experimental part
p. 1463 - 1476
(2009/12/24)
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- Process for the production and purification of bis(tertiary-butylamino)silane
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A process for synthesizing an aminosilane compound such as bis(tertiarybutylamino)silane is provided. In one aspect of the present invention, there is provided a process for making bis(tertiarybutylamino)silane comprising reacting a stoichiometric excess
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- Synthesis, spectral characterization and crystal structures of organophosphonic diamides: Pyramidal nitrogen centers and hydrogen bonding in [PhP(O)(NHtBu)2], [PhP(O)(NHDipp)2] (Dipp = 2,6-iPr2C6H3) and [tBuP(O)(NHiPr)2]
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Organophosphonic diamides of general formula [R1P(O)(NHR2)2] (1-8; R1 = Ph, Cy or tBu and R2 = Cy, iPr, tBu or Dipp) have been prepared by the addition of P,P′-dichloro(alkyl/aryl)phosphine oxide, R1P(O)Cl2, to a solution of primary amine in toluene. The synthesis of PhP(O)(NHtBu)2 (1) in high yield was achieved by slow oxidation of PhP(NHtBu)2 in air over several days. All new compounds have been characterized by elemental analysis and by IR, EI mass and NMR (1H and 31P) spectroscopy. The molecular structures of [PhP(O)(NHtBu)2] (1), [PhPO(NHDipp)2] (2) and [tBuP(O)(NHiPr)2] (7) have been determined by single crystal X-ray diffraction studies. The amido nitrogen atoms in 1, 2 and 7 show considerable deviation from the expected trigonal-planar geometry. The observed dihedral angles and the orientation of the nitrogen lone pair (l.p.) in these compounds point to the role of l.p.(N) → σ*(P-X) type negative hyperconjugative interactions in P-N multiple bonding. Compounds 1 and 7 form interesting polymeric structures in the solid state with the aid of N-H...O=P hydrogen bonding interactions while the presence of the very bulky Dipp substituent on nitrogen in 2 prevents the participation of the N-H protons in hydrogen bonding with phosphoryl oxygen atoms.
- Murugavel, Ramaswamy,Pothiraja, Ramasamy
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p. 968 - 974
(2007/10/03)
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- Intramolecular nucleophilic catalysis and the exceptional reactivity of N-benzyloxycarbonyl α-aminophosphonochloridates
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The intramolecular nucleophilic catalysis and the exceptional reactivity of N-benzyloxycarbonyl α-aminophosphonochloridates were discussed. It was found that N-benzyloxycarbonyl derivatives of α-aminophosphonochloridates were highly reactive because of in
- Cullis, Paul M.,Harger, Martin J.P.
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p. 1538 - 1543
(2007/10/03)
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- Radical cations of trialkylamines: ESR spectra and structures
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Novel syntheses of cyclopropyldiisopropylamine (15), di-tert- butylcyclopropylamine (16), dicyclopropylisopropylamine (17), and tricyclopropylamine (18) are described. Hyperfine data were determined by ESR spectroscopy for the radical cations of these trialkylamines, as well as for those of ethyldiisopropylamine (10), diisopropyl-n-propylamine (11), dicyclohexylethylamine (12), diisopropyl-3-pentylamine (14), and 1- azabicyclo[3.3.3]undecane (manxine; 27). The radical cation of triisopropylamine (13) was reexamined under conditions of improved spectral resolution. Coupling constants of the 14N nucleus and the β-protons in the radical cations of 18 trialkylamines provide reliable information about the geometries of these species, which are confirmed by theoretical calculations. With the exception of a few oligocyclic amines, for which flattening is impaired by the rigid molecular framework, all of the radical cations should be planar. Correlation between the observed coupling constants of the β- protons and the calculated 2 θ> values of the dihedral angle θ, defining the conformation of the alkyl substituent or the azacycloalkane, is verified. Upon oxidation, striking changes occur for those amines that have cyclopropyl substituents, because of the tendency of these groups to assume a perpendicular conformation in the neutral amines and a bisected orientation in the corresponding radical cations.
- De Meijere, Armin,Chaplinski, Vladimir,Gerson, Fabian,Merstetter, Pascal,Haselbach, Edwin
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p. 6951 - 6959
(2007/10/03)
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- Reactions of the Boron Hydrides B3H7 and B5H9 with the Unsaturated Boron-Nitrogen Compounds NBtBu2 and NB2tBu3
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THF*B3H7 reacts with RBNR (1, R = tBu) to yield the μ-amino-diborane (6) B2H4R(NHR) (5), which crystallizes in the triclinic space group P1.The reaction of B3H7 with the azadiboriridine NB2tBu3 (2, R = tBu) leads to the known NB2R3*BH3 (4) and the novel (NB2R3)2B2H4 (6).Product 6 is considered to represent a diaza-arachno-octaborane derivative.The iminoborane 1 reacts with B5H9 in the presence of lutidine (L) to give the ionic product (7); our earlier report on the formation of the aza-arachno-heptaborate has to be revised.The products from the reaction of B5H9 with NB2R3 are 4 and 6. - Key Words: Iminoboranes / Azadiboriridines / Diaza-arachno-octaborane / arachno-Nonaborate(1-)
- Kuepper, Stefan,Paetzold, Peter,Boese, Roland
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p. 1787 - 1790
(2007/10/02)
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- Substituted-amine compound and a process for the preparation thereof
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The compound (-)-N-t-butyl-4,4-diphenyl-2-cyclopentenylamine, or its hydrochloride salt has anticholinergic activity, and thus has a variety of pharmaceutical utilities.
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- Reactions of a sulfido-bridged dinuclear molybdenum complex with nitriles and isonitriles under hydrogen: Facile C≡N bond cleavage
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The dinuclear complex [(CpMo)2(S2CH2)(μ-S)(μ-SH)] +X- (X = SO3CF3, BF4; Cp = C5H5; 1(X)) reacted with nitriles RCN under 1-2 atm of H2 at 25-50°C to form the new cationic complex [CpMo(S2CH2)(S2CR)MoCp]+ and ammonia. The reaction has been characterized for HCN as well as for a series of alkyl- and aryl-substituted nitriles. Complex 1 reacted with isonitriles (RNC) and hydrogen under similar conditions to form the cationic complex [CpMo(S2CH2)(S2CH)MoCp]+ and the primary amine RNH2. The reactions were inhibited by excess acid. In order to probe the mechanisms of these reactions, the interactions of nitriles and isonitriles with 1 in the absence and presence of a protic acid and in the absence and presence of hydrogen have been studied. In the absence of hydrogen, 1 reacted with isonitriles to form [(CpMo)2(S2CH2)(S2CNH(R))] + (2), but no reaction of 1 with nitriles was detected spectroscopically. Under similar conditions in the presence of excess protic acid, 1 reacted with n-butyl isocyanide to form [(CpMo)2(S2CH2)(μ-S)(μ-SCH=NHBu)] 2+ (4) and with acetonitrile to form [(CpMo)2(S2CH2)(μ-S)(μ-SC(CH 3)=NH2)]2+ (5). These S-H insertion products were identified by spectroscopic methods. The reaction of 4 and 5 with hydrogen appeared to involve carbon-sulfur bond hydrogenolysis; e.g., in the reaction of 5 with H2, ethylammonium ion was identified as a product. The C-N bond cleavage reactions are proposed to involve the deprotonated forms of the insertion products 4 and 5, [(CpMo)2(S2CH2)(μ-S)(μ-SCH=NBu)] + and [(CpMo)2(S2CH2)(μ-S)(μ-SC(CH 3)=NH)]+. The former complex was tentatively identified by NMR spectroscopy. Reactions of these derivatives with hydrogen are proposed to lead to intramolecular S-H insertion products [(CpMo)2(S2CH2)(S2CH(NH 2Bu))]+ (6) and [(CpMo)2(S2CH2)(S2C(CH 3)NH3)]+ (7). A precedent for this type of reaction has been characterized in a related molybdenum system. Complexes 6 and 7 are expected to eliminate BuNH2 and NH3, respectively, to form the final molybdenum products. The possible relevance of these reactions to the reductions of nitriles and isonitriles effected by the nitrogenase enzymes is discussed.
- Bernatis, Paul,Laurie,DuBois, M. Rakowski
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p. 1607 - 1617
(2008/10/08)
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- Aminations with O-Diphenylphosphinylhydroxylamine. A Critical Evaluation
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A critical evaluation is presented of the scope of amination reactions with O-diphenylphosphinylhydroxylamine (ODPH) as compared to those using hydroxylamine-O-sulfonic acid (HOSA).Aminations with ODPH of isopropyl, t-butyl and cyclohexyl carbanions derived from the corresponding Grignard reagents, gave the corresponding amines in 36, 34 and 50 percent yields, respectively.The amination with HOSA of the same carbanions under similar conditions was unsuccessful.The aminative quaternization of the tertiary nitrogen of pyridine and quinoline with ODPH proceeded with comparable yields to those obtained with HOSA.An improved one flask amination with ODPH of indole, skatole and carbazole was achieved in 52 - 62 percent yields.The amination under the same conditions using HOSA gave consistently lower yields.Several other amination reactions which have been reported for HOSA were unsuccessful using ODPH.The conclusion is reached that overall the ODPH reagent is much less versatile than HOSA.Nevertheless, in the aminations of NH groups of heterocyclic compounds ODPH appears to be superior to HOSA and is the reagent of choice, in particular, since the preparation of ODPH is much less harzardous than that of HOSA. - Keywords: Synthesis, O-Diphenylphosphinylhydroxylamine, Hydroxylamine-O-sulfonic Acid, N-Amino Derivatives, N-Amino Heterocyclic Compounds
- Sosnovsky, George,Purgstaller, Klaus
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p. 582 - 586
(2007/10/02)
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- Synthesis and Reactivity of N-Substituted-1-amino-2-(methylsulfonyl)-3-phenyl-2-propenes
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The synthesis of 3-bromo-2-(methylsulfonyl)-1-phenyl-1-propene (1b) is described.Reaction of the allyl bromide 1b with tert-butylamine, diisopropylamine, glycine methyl ester, and piperidine in benzene solution yielded mixtures of direct substitution (SN2) and substitution-rearrangement (SN2') products, 2 and 3, respectively.The SN2:SN2' ratio ranged from 1:4 for reaction of 1b with glycine methyl ester to greater than 20:1 for the reaction with diisopropylamine.Amine hydrochloride promoted amine exchange reactions of N,N-diisopropyl-1-amino-2-(methylsulfonyl)-3-phenyl-2-propene (2a) and the amine exchange and aminotropic rearrangement reactions of the thermodynamically less stable N-tert-butyl-1-amino-2-(methylsulfonyl)-1-phenyl-2-propene (3b) are described.Evidence for acid-catalyzed aminotropic rearrangement and amine exchange reactions (3-->2) is presented.Equilibrium constants for reactions of 2a and of 2b with piperidine hydrochloride in chloroform solution were determined.
- Doomes, Earl,Overton, Belinda M.
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p. 1544 - 1548
(2007/10/02)
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- A Simple, One-Pot Transformation of t-Alkyl Chlorides Into (t-Alkyl)amines
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t-Alkyl chlorides are readily azidated using trimethylsilyl azide in the presence of tin tetrachloride.Tertiary azides can be transformed without isolation into the corresponding (t-alkyl)amine hydrochlorides in a one-pot procedure employing the Staudinger reaction.
- Koziara, Anna,Osowska-Pacewicka, Krystyna,Zawadzki, Stefan,Zwierzak, Andrzej
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p. 487 - 489
(2007/10/02)
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- Nitrogen-containing organosilicon compounds
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A nitrogen-containing organosilicon compound represented by the general formula: wherein R1 stands for a saturated or unsaturated monovalent hydrocarbon group of 1 to 8 carbon atoms, R2 for a saturated or unsaturated monovalent hydrocarbon group of 1 to 6 carbon atoms, Y for STR1 a for an integer of the value of 1 to 3, and b for an integer of the value of 1 to 2.
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- Photo-promoted Oxidation of Alcohols with Aliphatic N-Chloroamines
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Irradiation of N,N-dichloro-t-butylamine (1) with alcohols, especially alcohols of benzylic type, in CCl4 was found to give the corresponding ketones and aldehydes with quantitative formation of t-butylamine hydrochloride.The photoreaction of 1-phenylethanol with (1) in cyclohexane or toluene, however, gives mainly solvent-chlorinated products together with a low yield of acetophenone.The oxidation is suppressed by HCl scavengers (triethylamine or epichlorohydrin) and accelerated by the addition of HCl irrespective of irradiation.The irradiation may induce generation of Cl and then HCl, the latter exerting autocatalysis for the oxidation in the dark.An ionic mechanism via protonated (1) and alkyl hypochlorite is postulated and discussed.
- Ogata, Yoshiro,Kimura, Makoto
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p. 947 - 950
(2007/10/02)
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- N,N'-BIS(1-CHLOROALKYL)CARBODIIMIDES. II. REACTIONS WITH PROTON-CONTAINING NUCLEOPHILIC REAGENTS
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The reactions of N,N'-bis(1-chloroalkyl)carbodiimides with proton-containing nucleophilic reagents were investigated.It was shown that substitution products retaining the carbodiimide structure are formed in the reactions with alcohols and phenols.The action of water or primary amines is accompanied by fragmentation of the molecule and leads to the production of chloroformamidine or N-substituted guanidines.Secondary amines act on N,N'-bis(1-chloroalkyl)carbodiimides to form diazadienes, which exist as mixtures of Z,E isomers.
- Fetyukhin, V. N.,Vovk, M. V.,Pirozhenko, V. V.,Samarai, L. I.
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p. 1822 - 1828
(2007/10/02)
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- 4,5-Dimethyl-thieno[3,2-d]isothiazolo-3(2H)-one-1,1-dioxides, compositions, and methods of use as a sweetener
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Compounds of the formula STR1 wherein X is oxygen or sulfur; R1 is hydrogen, methyl or ethyl; and R2 is methyl or ethyl; and non-toxic, physiologically acceptable salts thereof formed with an inorganic or organic base. The compounds
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