- The reaction of 4-substituted aryl isocyanates with NaBH4/trifluoroacetic acid (TFA)
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Treatment of 4-substituted aryl isocyanates (cf. 2a-f) with NaBH4/TFA leads to the corresponding 4-substituted N,N-bis(2,2,2-trifluoroethyl)aniline derivatives (3a-d) in excellent yield except where an electron-withdrawing group is present (cf.
- Turnbull, Kenneth,Krein, Douglas M.
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Read Online
- Surface modification of polymers with bis(arylcarbene)s from bis(aryldiazomethane)s: preparation, dyeing and characterization
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Modification of polymer beads by bis(arylcarbene) insertion provides access to materials with similar bulk properties, but different surface chemical characteristics, compared to the unmodified polymer. A subsequent dyeing process using different diazonium salts generates colored polymers with a variety of surface functional groups. XPS and solid state NMR spectra were used to characterize modified and dyed polymers, which showed this protocol was both successful and general. BET data showed that the surface area changed significantly after modification, while BJH data showed pore size distribution was unchanged. TG/DSC analysis and Elemental Analysis were also used to characterize modified polymers. This permitted calculation and comparison of the loadings of surface area and the modification effects with different chemical structure of bis(arylcarbene)s. This work shows that the bis(arylcarbene) system is as effective as mono(arylcarbene)s, but of significance since the starting bis(aryldiazomethane)s are more easily accessible and easier to handle than the mono(aryldiazomethane)s. All this data indicates that the surface property of polymers is modified.
- Yang, Pengfei,Moloney, Mark G.
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p. 111276 - 111290
(2016)
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Read Online
- Carbon-Carbon Bond Formation of Trifluoroacetyl Amides with Grignard Reagents via C(O)-CF3 Bond Cleavage
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The reaction of trifluoroacetyl amides with Grignard reagent for the substitution of CF3 group with various alkyl or aryl groups is described. A variety of aryl, quinolin-8-yl, and (hetero)alkyl functional groups as well as F, Cl, and Br atoms are well tolerated. These moisture-stable and easily available trifluoroacetyl amides can be conveniently obtained and used as new versatile precursors for isocyanates. The control experiments show that the reaction proceeds via an isocyanate intermediate and/or alkoxide/amide dual anionic intermediate.
- Zhu, Longzhi,Le, Liyuan,Yan, Mingpan,Au, Chak-Tong,Qiu, Renhua,Kambe, Nobuaki
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p. 5635 - 5644
(2019/05/10)
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- Removal of some common glycosylation by-products during reaction work-up
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With the aim of improving the general glycosylation protocol to facilitate easy product isolation it was shown that amide by-products from glycosylation with trichloroacetimidate and N-phenyl trifluoroacetimidate donors could be removed during reaction work-up by washing with a basic aqueous solution. Excess glycosyl acceptor or lactol originating from glycosyl donor hydrolysis could equally be removed from the reaction mixture by derivatization with a basic tag and washing with an acidic solution during reaction work-up.
- Heuckendorff, Mads,Jensen, Henrik H.
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- Regioselective ortho-nitration of N-phenyl carboxamides and primary anilines using bismuth nitrate/acetic anhydride
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An efficient and one-pot synthetic method for the regioselective ortho-nitration of the N-phenyl carboxamides and primary anilines has been developed by using bismuth nitrate and acetic anhydride as the nitrating reagents. Reaction proceeds at room temperature and results in corresponding ortho-nitrated products in moderate to excellent yields. This method provides an operationally simple, regioselective, and efficient access to synthesize o-nitro anilines under the mild conditions.
- Lu, Yang,Li, Yaming,Zhang, Rong,Jin, Kun,Duan, Chunying
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supporting information
p. 9422 - 9427
(2013/10/08)
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- The development of N-aryl trifluoroacetimidate-based benzyl and allyl protecting group reagents
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An exploration of the role of para-substituents on the balance between stability and reactivity of N-phenyl trifluoroacetimidates prompted the discovery of new reagents for the addition of allyl and benzyl protecting groups, namely O-allyl and O-benzyl N-
- Tsabedze, Sinele B.,Kabotso, Daniel E.K.,Pohl, Nicola L.B.
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p. 6983 - 6985
(2013/12/04)
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- The reaction of 2-arylazo-1-vinylpyrroles with trifluoroacetic anhydride: Unexpected formation of N-aryl-2,2,2-trifluoroacetamides and conjugated polymers
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2-Arylazo-1-vinylpyrroles under the action of trifluoroacetic anhydride (CH2Cl2 or benzene, -5-0 °C, 1 h) form N-aryl-2,2,2-trifluoroacetamides along with conjugated (electroconducting and paramagnetic) polymers.
- Schmidt, Elena Yu.,Ushakov, Igor A.,Zorina, Nadezhda V.,Mikhaleva, Albina I.,Trofimov, Boris A.
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experimental part
p. 36 - 37
(2012/04/10)
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- A simple and efficient method for trifluoroacetylation of arylamines using trifluoroacetic acid and triphosgene
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A simple and efficient one-pot procedure for trifluoroacetylation of arylamines using trifluoroacetic acid and triphosgene is reported. A mixed trifluoroacetic anhydride generated in situ reacts with a variety of arylamines to give the corresponding trifluroacetamides in high yields.
- Han, Ki-Jong,Kim, Misoo
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experimental part
p. 559 - 561
(2012/06/04)
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- Trifluoroacetylation of amines with trifluoroacetic acid in the presence of trichloroacetonitrile and triphenylphosphine
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We developed a mild and convenient trifluoroacetylation process for amines using a combination of trichloroacetonitrile and triphenylphosphine. The reaction that we designed is applicable to the trifluoroacetylation of a wide variety of amines, including amines with stereogenic centers, which underwent trifluoroacetylation without racemization.
- Kim, Joong-Gon,Jang, Doo Ok
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scheme or table
p. 683 - 685
(2010/04/02)
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- A one-pot procedure for trifluoroacetylation of arylamines using trifluoroacetic acid as a trifluoroacetylating reagent
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A convenient procedure for the preparation of aryl trifluoroacetamides from aryl amines is described that employs 2-4 M equiv of trifluoroacetic acid in refluxing xylene as a trifluoroacetylating agent. Addition of an amount of pyridine that is equimolar to the amount of trifluoroacetic acid present in the reaction mixture facilitates the trifluoroacetylation of rather basic arylamines.
- Ohtaka, Junpei,Sakamoto, Takeshi,Kikugawa, Yasuo
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experimental part
p. 1681 - 1683
(2009/09/05)
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- Copper-catalyzed synthesis of primary arylamines from aryl halides and 2,2,2-trifluoroacetamide
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A catalytic method was developed to synthesize primary arylamines from the corresponding aryl bromides and iodides under mild conditions (yields = 80-99%). Crystalline 2,2,2-trifluoroacetamide was used as ammonia surrogate and CuI/N,N′-dimethyl ethylenediamine was used as catalyst to achieve the C-N cross-coupling.
- Tao, Chuan-Zhou,Li, Juan,Fu, Yao,Liu, Lei,Guo, Qing-Xiang
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- SHORT-ACTING BENZODIAZEPINES
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It has now been found that compounds of the present invention as described in Benzodiazepine derivatives of Formula (I) containing a carboxylic ester moiety and thereby capable of being inactivated by nonspecific tissue esterases in an organ-independent elimination mechanism and thereby providing a more predictable and reproducible pharmacodynamic profile. The compounds of the present invention are suitable for therapeutic purposes, including sedative-hypnotic, anxiolytic, muscle relaxant and anticonvulsant purposes and are useful to be administered intravenously in the following clinical settings: preoperative sedation, anxiolysis, and amnestic use for perioperative events; conscious sedation during short diagnostic, operative or endoscopic procedures; as a component for the induction and maintenance of general anesthesia, prior and/or concomitant to the administration of other anesthetic agents; ICU sedation.
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Page/Page column 12
(2008/06/13)
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- CHK-, PDK- AND AKT-INHIBITORY PYRIMIDINES, THEIR PRODUCTION AND USE AS PHARMACEUTICAL AGENTS
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This invention relates to pyrimidine derivatives of general formula (I) as inhibitors of kinases, their production as well as their use as medications for treating various diseases.
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Page 102; 106
(2008/06/13)
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- A short synthesis of phenanthro[2,3-d]imidazoles from dehydroabietic acid. Application of the methodology as a convenient route to benzimidazoles
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Methyl cis-deisopropyldehydroabietate was selectively nitrated at the 12-position by reaction with 'claycop', a montmorillonite clay impregnated with copper(II) nitrate. The 12-nitro compound was reduced to the corresponding amine and this was subjected to a combined acylation and ortho nitration. The compounds so produced were further converted into octahydro-1H-phenanthro[2,3-d]imidazoles by reductive cyclization. The same acylation-ortho nitration methodology was shown to provide a short synthesis of 2-substituted benzimidazoles from aniline.
- Fonseca, Tatiana,Gigante, Bárbara,Gilchrist, Thomas L
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p. 1793 - 1799
(2007/10/03)
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- A convenient synthesis of Trifluoroacetamides from sodium trifluoroacetate and amines
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Trifluoroacetamides were prepared readily by reaction of sodium trifluoroacetate with triphenylphosphine di-iodide and amines consecutively under mild conditions with good yields.
- Zhou, Qi-Zhong,Chen, Zhen-Chu
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p. 3189 - 3194
(2007/10/03)
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- Nitrogen containing heteroaromatics as factor Xa inhibitors
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The present application describes nitrogen containing heteroaromatics and derivatives thereof of formula I: or pharmaceutically acceptable salt or prodrug forms thereof, wherein J is N or NH and D may be C(=NH)NH2, which are useful as inhibitors of factor Xa.
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- A convenient trifluoroacetylation reagent: N- (trifluoroacetyl)succinimide
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N-(Trifluoroacetyl)succinimide, easily prepared from trifluoroacetic anhydride and succinimide forms a novel, convenient trifluoroacetylating reagent. It trifluoroacetylates alcohols, phenols and mines, to generate trifluoroacetate esters, and trifluoroacetamides in excellent yields with very efficient work up procedures.
- Katritzky, Alan R.,Yang, Baozhen,Guofang, Qiu,Zhang, Zhongxing
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- Novel generation of phenylnitrenium ions from S,S-dialkylanilinosulfonium salts in trifluoroacetic acid and formation of anilines by a new intramolecular hydride-shift to the phenylnitrenium ions
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Reactions of S,S-dialkylanilinosulfonium salts in trifluoroacetic acid give anilines, trifluoroacetanilides and dialkyl sulfoxides via novel intramolecular hydride-shift from the α-C-H of sulfide to phenylnitrenium ions (not completely free from the sulfide) interacting with both the unshared electron pair of the sulfide and the counter ion.
- Takeuchi, Hiroshi,Taniguchi, Tomohito,Masuzawa, Mamoru,Isoda, Kazuya
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p. 1743 - 1746
(2007/10/03)
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- Phosphorus in organic synthesis. Acyloxyphosphonium salts as chemoselective acylating reagents
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Acyloxytriphenylphosphonium salts 1 prepared in situ react with a variety of aminophenols to give the corresponding amides in excellent yields. At -25°N-acylated products are formed exclusively, whereas 0°some O-acylated products are observed. 1 is also a
- Froyen, Paul
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p. 5359 - 5362
(2007/10/03)
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- Water catalyzed hydrolysis of p-nitrotrifluoroacetanilide and trifluoroacetanilide. Carbonyl 18O-exchange does not accompany the water reaction
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The water catalyzed hydrolyses of p-nitrotrifluoroacetanilide (3) and trifluoroacetanilide (8) were studied at various pH's and temperatures. The activation parameters for the water reactions of 3 and 8 are: ΔH = 14.4 ± 0.6 and 11.7 ± 0.3 kcal/mol and ΔS = -36.1 ± 1.8 and -52.3 ± 0.7 calmol·K, respectively. These are consistent with reactions that involve considerable restriction of degrees of freedom of the solvent/substrate in the transition state. A proton inventory analysis of the rate constants for hydrolysis of 3 in media of different mole fraction D2O indicates the process involves two or more protons in flight or undergoing loosening of their bonding in the transition state. 18O-Labeled amides were subjected to the hydrolytic conditions for various times up to 3 half-times of hydrolysis and recovered. Mass analysis showed that the 180 content in the recovered amide did not change during the course of the reaction. All the data support a process where the rate-limiting step for the water reaction involves a concerted or nearly concerted formation of a diol which undergoes subsequent C-N cleavage in preference to OH expulsion.
- Slebocka-Tilk,Rescorla, Christopher G.,Shirin, Salma,Bennet, Andrew J.,Brown
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p. 10969 - 10975
(2007/10/03)
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- Micellar catalysis of organic reactions. Part 37. A comparison of the catalysis of ester and amide hydrolysis by copper-containing micelles
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The hydrolysis of a number of nitroactivated esters and amides has been studied in the presence of copper-containing metallomicelles at neutral pH. The relative rates of hydrolysis in the pure metallomicelle and in co-micelles with either cetyltrimethylammonium bromide (ctab) or Triton X-100 depends on the hydrophobicity of the substrate and whether it is completely solubilized by the copper micelle. Thus it depends on the concentration of the copper micelle. At low concentrations of copper micelle (0.2 mM) where the substrate is incompletely solubilized, the reaction is faster when 2 mM crab is added. At higher concentrations (>0.6 mM) where the substrate may be almost completely solubilized by the copper micelle, the reaction is slower when 2 mM crab is added. For ester hydrolysis the presence of either a carboxylic acid group or a heterocyclic nitrogen atom close to the reaction centre resulted in much larger catalysis by the metallomicelle than for model compounds without these additional groups. It is postulated that these groups coordinate with the metal ion and thus present the reaction centre close to a metal-bound hydroxyl resulting in a significant increase in the rate of bond formation, which is the rate-determining step for ester hydrolysis. For amide hydrolysis the presence of a carboxyl group ortho to the reaction centre did not lead to larger catalysis by the copper micelle than for the compound without this group. This difference is attributed to the different rate-determining steps for amide and for ester hydrolysis.
- Broxton,Nasser
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p. 202 - 206
(2007/10/03)
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- The reaction of 4-substituted aroyl azides with NaBH4/TFA
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Treatment of 4-substituted aroyl azides (cf. 1a-e) with NaBH4/TFA leads to the corresponding, novel 4-substituted N,N-di(2,2,2-trifluoroethyl)aniline derivatives (2a-e) in excellent yield except where electron-withdrawing groups are present (cf. 1f-g).
- Krein, Douglas M.,Sullivan, Pamela J.,Turnbull, Kenneth
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p. 7213 - 7216
(2007/10/03)
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- Ozone-mediated Reaction of Anilides and Phenyl Esters with Nitrogen Dioxide: Enhanced Ortho-reactivity and Mechanistic Implications
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In the presence of ozone, anilides 1 can be nitrated rapidly with nitrogen dioxide in chloroform at 0 deg C to give a high proportion of ortho-nitro derivatives (ortho:para = 1.2-4.4) in good yields.The phenyl esters 15 can be similarly nitrated on the aromatic ring without significant cleavage of the ester bond, giving a mixture of isomeric nitro derivatives in which the ortho-isomer predominantes (ortho:para = 1.1-1.5).The oridin of the enhanced ortho reactivity is discussed in terms of an electron-transfer process involving the nitrogen trioxide as initial electrophile.
- Suzuki, Hitomi,Tatsumi, Atsuo,Ishibashi, Taro,Mori, Tadashi
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p. 339 - 344
(2007/10/02)
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- Effect of Cyclodextrins on the Hydrolysis of Amides
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The hydrolysis of p-nitrotrifluoroacetanilide (1), trifluoroacetanilide (2), m-nitrotrifluoroacetanilide (3), and p-nitroacetanilide (4) was studied in the presence of cyclodextrins.The reactions of 1 are catalyzed by α-cyclodextrin (α-CD) and β-cyclodextrin (β-CD) and also by hydroxypropyl)cyclodextrin (HPCD).The hydrolysis of 4 is catalyzed by β-CD.The reaction of 2 is inhibited by β-CD and so is the reaction of 3 by HPCD.Copounds 1 and 4 form two types of inclusion coplexes with β-CD, a 1:1 and a 1:2 substrate:cyclodextrin complex.Both types of complexesreact faster than the free substrate, and for 1 at pH = 7 all the catalysis is due to the reaction of the 1:2 complex since the 1:1 complex reacts at about the same rate as the free substrate.The results are explained in terms of two mechanisms: one which involves the acylation of CD by the amides and another which predominates at neutral pH where the two cyclodextrins coplexing the substrate stabilize the transition state for water addition.
- Granados, Alejandro,Rossi, Rita H. de
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p. 1771 - 1777
(2007/10/02)
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- 2-(Trifluoroacetyloxy)pyridine as a Mild Trifluoroacetylating Reagent of Amines and Alcohols
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A new trifluoroacetylating reagent, 2-(trifluoroacetyloxy)pyridine (TFAP), was prepared by the reaction of 2-pyridinol and trifluoroacetic anhydride.TFAP has been found to be effective in the trifluoroacetylation of aliphatic and aromatic amines and alcohols including phenol under mild conditions.The reaction of p-nitrophenol with TFAP in ether gave the hydrogen-bonded complex between the phenol and 2-pyridone.This reagent has also been shown to be useful for the intramolecular dehydration of aldehyde oximes and amides to give nitriles in high yields.
- Keumi, Takashi,Shimada, Masakazu,Morita, Toshio,Kitajima, Hidehiko
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p. 2252 - 2256
(2007/10/02)
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