- Safe synthesis of alkylhydroxy and alkylamino nitramines
-
Three different protocols for the syntheses of hydroxyalkylnitramines are presented and compared. Safety issues regarding the synthesis of nitramines are also discussed.
- Antonsen, Simen,Aursnes, Marius,Gallantree-Smith, Harrison,Dye, Christian,Stenstr?m, Yngve
-
-
Read Online
- Synthesis and properties of hypericins substituted with acidic and basic residues: Hypericin tetrasulfonic acid - A water soluble hypericin derivative
-
Sulfonation of hypericin leads to its di-, tri-, and tetrasulfonic acid derivatives. The latter is soluble in water up to millimolar solutions. Homoaggregate formation (J-aggregates) was observed only above 5 · 10-4 mol/1. In water solutions, the tetrasulfonic acid hypericin derivative was found to be present as its bay-phenolate with most of the sulphonic acids dissociated. Thus, the first water soluble hypericin derivative, which in contrast to hypericin is not prone to homoassociation, is presented. Hypericin tetrtasulfonic acid forms heteroassociates with serum albumin, DNA, and γ-cyclodextrin. Hypericin derivatives with primary and tertiary amino group appendages at the hypericin methyl groups were synthesized. However, upon salt formation or quaternization these derivatives became virtually insoluble in all common solvents including water.
- Falk, Heinz,Sarhan, Abd-El-Wareth A. O.,Tran, Huyen T. N.,Altmann, Robert
-
-
Read Online
- Switching Lysophosphatidylserine G Protein-Coupled Receptor Agonists to Antagonists by Acylation of the Hydrophilic Serine Amine
-
Three human G protein-coupled receptors (GPCRs)—GPR34/LPS1, P2Y10/LPS2, and GPR174/LPS3—are activated specifically by lysophosphatidylserine (LysoPS), an endogenous hydrolysis product of a cell membrane component, phosphatidylserine (PS). LysoPS consists of-serine, glycerol, and fatty acid moieties connected by phosphodiester and ester linkages. We previously generated potent and selective GPCR agonists by modification of the three modules and the ester linkage. Here, we show that a novel modification of the hydrophilic serine moiety, that is, N-acylations of the serine amine, converted a GPR174 agonist to potent GPR174 antagonists. Structural exploration of the amide functionality provided access to a range of activities from agonist to partial agonist to antagonist. The present study would provide a new strategy for the development of lysophospholipid receptor antagonists.
- Sayama, Misa,Uwamizu, Akiharu,Ikubo, Masaya,Chen, Luying,Yan, Ge,Otani, Yuko,Inoue, Asuka,Aoki, Junken,Ohwada, Tomohiko
-
p. 10059 - 10101
(2021/07/28)
-
- Preparation method of N-vinyl alkylamide
-
The invention relates to the technical field of vinyl compound production, in particular to a preparation method of Nvinyl alkyl amide. The preparation method comprises the following steps: A) under the action of a composite basic catalyst, reacting acetaldehyde with alkylamide to obtain Nhydroxyethyl alkylamide, and carrying out esterification reaction on the obtained Nhydroxyethyl alkylamide andacid anhydride to obtain an ester compound; wherein the composite basic catalyst comprises an inorganic base and an amine compound; and B) carrying out medium-temperature cracking on the ester compound, and carrying out vacuum distillation to obtain the Nvinyl alkylamide. Research finds that inorganic base and amine compounds are adopted as catalysts at the same time, so that the dosage of a basic catalyst required by reaction of Nhydroxyethyl alkylamide and anhydride can be remarkably reduced, the temperature required by subsequent cracking reaction is reduced, a reaction system tends to bemilder, and the reaction yield is improved. The yield and the purity of a reaction product can be remarkably improved while the energy consumption is reduced.
- -
-
Paragraph 0067-0068; 0073-0074
(2020/12/29)
-
- Method for preparing 3-ketomorpholine
-
The invention relates to a method for preparing 3-ketomorpholine. The method comprises the following steps: protecting the amino group of ethanolamine firstly, then carrying out a reaction of amino group protected ethanolamine with alkyl haloacetate, performing deprotection on the prepared product, and performing ring closure so as to obtain 3-ketomorpholine. The method has the advantages of simple practical operation, low equipment requirements, high yield and low three waste, and is suitable for industrial large-scale production.
- -
-
Paragraph 0062-0064
(2019/03/26)
-
- Metal-Free O-Selective Direct Acylation of Amino Alcohols Through Pseudo-Intramolecular Process
-
Efficient α-aryl-β-keto ester acylation of amine accompanied by the elimination of ethyl phenylacetate was achieved owing to the pseudo-intramolecular process. The eliminated ethyl phenylacetate could be recycled by conversion into an α-aryl-β-keto ester upon treatment with an acyl chloride in the presence of lithium bis(trimethylsilyl)amide, by which the atom economy considerably increased. Acylation using an α-aryl-β-keto ester is highly sensitive to the bulkiness of the nucleophile, which facilitated the regioselective-acylation of the less hindered amino group in diamine without protecting the other. The transacylation of α-aryl-β-keto ester with N-alkylamino alcohol resulted in chemoselective O-acylation without protecting the amino group because the hydroxy group was attracted to the reaction site of the keto ester by forming an ammonium salt. Transacylation was demonstrated to be a practically useful tool for organic synthesis because this protocol can be conducted under mild conditions with simple manipulations in the absence of any additives such as metal catalyst and base.
- Yokoyama, Soichi,Shibauchi, Hiroshi,Asahara, Haruyasu,Nishiwaki, Nagatoshi
-
p. 1125 - 1133
(2019/02/01)
-
- Formation of carbon–nitrogen bonds in carbon monoxide electrolysis
-
The electroreduction of CO2 is a promising technology for carbon utilization. Although electrolysis of CO2 or CO2-derived CO can generate important industrial multicarbon feedstocks such as ethylene, ethanol, n-propanol and acetate, most efforts have been devoted to promoting C–C bond formation. Here, we demonstrate that C–N bonds can be formed through co-electrolysis of CO and NH3 with acetamide selectivity of nearly 40% at industrially relevant reaction rates. Full-solvent quantum mechanical calculations show that acetamide forms through nucleophilic addition of NH3 to a surface-bound ketene intermediate, a step that is in competition with OH– addition, which leads to acetate. The C–N formation mechanism was successfully extended to a series of amide products through amine nucleophilic attack on the ketene intermediate. This strategy enables us to form carbon–heteroatom bonds through the electroreduction of CO, expanding the scope of products available from CO2 reduction.
- Jouny, Matthew,Lv, Jing-Jing,Cheng, Tao,Ko, Byung Hee,Zhu, Jun-Jie,Goddard, William A.,Jiao, Feng
-
p. 846 - 851
(2019/09/03)
-
- Pivotal role of intramolecular catalysis in the selective acetylation of alkyl amines
-
Preparation of amides by the use of esters as the "acyl donor" is less explored because they are less reactive and usually more steric demanding than conventional acid halides and anhydrides. Here, we report that 3-acetoxy-2-naphthoic acid, an aspirin analogue, can be used as a mild amine acetylating agent in ethanol at 25°C. The reaction is sensitive to steric and polar effects of the attacking amine, and the rate constants can be appropriately fitted by the Pavelich-Taft correlation. Density functional theory calculations used to study all reaction steps indicate that the o-carboxy group plays a pivotal role, guiding the attacking amine and accelerating the reaction. The reaction can be conveniently used for the acylation of a variety of primary and secondary amines.
- Nishida, Elvis N.,Vitto, Ramon,Peixoto, R?mulo C.R.,Nome, Faruk,Souza, Bruno S.
-
-
- METHOD OF MAKING A COMPOSITION OF AN ALKANOLAMINE ALKYLAMIDE AND A POLYOL
-
The disclosure generally provides methods for preparing compositions comprising alkanolamine alkylamides and polyols. This disclosure further relates to methods for preparing compositions comprising alkanolamine alkylamides and polyols that can be used in formulations that provide moisturization.
- -
-
Paragraph 0067
(2017/08/22)
-
- Hydrolytic hydrogenation of chitin to amino sugar alcohol
-
Chitin is the second most abundant biomass and characteristically contains nitrogen atoms in its monomer units. These favourable features promote chitin to be a potential resource for renewable organonitrogen compounds. 2-Acetamido-2-deoxysorbitol (ADS) is an attractive target in the derivatives of chitin, but the conversion of chitin to ADS has not been reported so far. In this work, we demonstrate the catalytic conversion of chitin to ADS using mechanocatalysis in the presence of H2SO4 and subsequent hydrolytic hydrogenation by H2SO4 and Ru/TiO2 without any purification process. Our study clarified that the yield of ADS is strongly influenced by the reaction temperature and pH. The hydrolysis favourably proceeds at high temperature and low pH (2.0), but the hydrogenation needs a low temperature and a specific pH of 3-4 to achieve high selectivity. Specifically, in the hydrogenation step, an acid causes various side-reactions of amide and hemiacetal groups especially in the presence of a Ru catalyst, whereas even a small amount of base drastically accelerates the retro-aldol reaction to form erythritol and N-acetylethanolamine. Therefore, a one-pot but two-step reaction is necessary to optimise both the hydrolysis and hydrogenation steps and maximise the overall yield of ADS up to 52%.
- Kobayashi, Hirokazu,Techikawara, Kota,Fukuoka, Atsushi
-
p. 3350 - 3356
(2017/07/28)
-
- FUMARATE COMPOUNDS, PHARMACEUTICAL COMPOSITIONS THEREOF, AND METHODS OF USE
-
Fumarate compounds, pharmaceutical compositions comprising the fumarate compounds, and methods of using fumarate compounds and pharmaceutical compositions for treating neurodegenerative, inflammatory, and autoimmune disorders including multiple sclerosis, psoriasis, irritable bowel disorder, ulcerative colitis, arthritis, chronic obstructive pulmonary disease, asthma, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis are disclosed.
- -
-
Paragraph 0454
(2017/02/24)
-
- FUMARATE COMPOUNDS, PHARMACEUTICAL COMPOSITIONS THEREOF, AND METHODS OF USE
-
Fumarate compounds, pharmaceutical compositions comprising the fumarate compounds, and methods of using fumarate compounds and pharmaceutical compositions for treating neurodegenerative, inflammatory, and autoimmune disorders including multiple sclerosis, psoriasis, irritable bowel disorder, ulcerative colitis, arthritis, chronic obstructive pulmonary disease, asthma, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis are disclosed.
- -
-
Paragraph 0634
(2017/02/24)
-
- Carboxyl activation of 2-mercapto-4,6-dimethylpyrimidine through n-acyl-4,6-dimethylpyrimidine-2-thione: A chemical and spectrophotometric investigation
-
2-Mercapto-4,6-dimethylpyrimidine, as effective carboxyl activating group, has been successfully proved by converting it into respective acyl derivatives and the subsequent conversion to the amides and esters respectively using amines, amino alcohols and alcohols. The aminolysis and esterification were monitored chemically and spectrophotometrically. This paved way to establish that the above mercaptopyrimidine derivative is an efficient carboxyl activating group applicable in solid phase peptide synthesis.
- Rajan
-
p. 287 - 291
(2015/01/30)
-
- Silica-supported boric acid catalyzed synthesis of dihydropyrimidin-2-ones, bis(indolyl)methanes, esters and amides
-
Silica-supported boric acid (H3BO3-SiO2) has been established as a green, efficient and recyclable catalyst for the synthesis of dihydropyrimidin-2-ones, bis(indolyl)methanes, and acetylation of alcohols, phenols, amines and thiols under solvent free conditions. The main features of the present method include clean reaction, mild conditions, low loading of environment friendly catalyst and easy workup procedure. The catalyst can be recycled at least five times without any significant loss in activity.
- Kumar, Vishal,Singh, Chitra,Sharma, Upendra,Verma, Praveen K.,Singh, Bikram,Kumar, Neeraj
-
-
- Transamidation of carboxamides catalyzed by Fe(III) and water
-
The highly efficient transamidation of several primary, secondary, and tertiary amides with aliphatic and aromatic amines (primary and secondary) is described. The reaction is performed in the presence of a 5 mol % concentration of different hydrated salts of Fe(III), and the results show that the presence of water is crucial. The methodology was also applied to urea and phthalimide to demonstrate its versatility and wide substrate scope. An example of its use is an intramolecular application in the synthesis of 2,3-dihydro-5H-benzo[b]-1,4- thiazepin-4-one, which is the bicyclic core of diltiazem and structurally related drugs (Budriesi, R.; Cosimelli, B.; Ioan, P.; Carosati, E.; Ugenti, M. P.; Spisani, R. Curr. Med. Chem. 2007, 14, 279-287). A plausible mechanism that explains the role of water is proposed on the basis of experimental observations and previous mechanistic suggestions for transamidation reactions catalyzed by transition metals such as copper and aluminum. This methodology represents a significant improvement over other existing methods; it can be performed in air and with wet or technical grade solvents.
- Becerra-Figueroa, Liliana,Ojeda-Porras, Andrea,Gamba-Sánchez, Diego
-
p. 4544 - 4552
(2014/06/09)
-
- Selectivities in acylation of primary and secondary amine with diacylaminoquinazolinones and diacylanilines
-
The diacylaminoquinazolinones are highly selective acylating agents for primary amines in the presence of secondary amines. The chemoselective N-acetylation reagents have been investigated using 2-substituted N,Ndiacylaminoquinazolinones (DAQs) and 2-substitued-N-diacylanilines (DAAs). Determination of the selectivity ratios have been made by comparison of the crude product in each case with authentic samples of the amide products using NMR spectroscopy. The control experiments in which pairs of amines compete for acetyl chloride show some selectivity but not comparable with that of DAQs and DAAs selectivity. When the DAQs, DAAs and acetyl chloride react with mixtures of pyrrolidine and piperidine, they give amides in the corresponding ratios. The DAQs 1 and 2 react entirely with diethylamine without any competitive reaction with diphenylamine. The high level of chemoselectivity has also been observed when the 1 and 2 react exclusively with the ethanolamine without any competitive reaction with diethanolamine. Moreover, 1 and 2 react with succinimide without any competitive reaction with phthalimide.
- Al-Sehemi, Abdullah G.,Al-Amri, Reem S. Abdul-Aziz,Irfan, Ahmad
-
p. 1115 - 1121
(2014/10/15)
-
- Organobase-catalyzed amidation of esters with amino alcohols
-
A base-mediated procedure for the amidation of unactivated esters with amino alcohols is reported. Optimization and exemplification of the catalytic process are described, furnishing products in 40-100% isolated yield.
- Caldwell, Nicola,Jamieson, Craig,Simpson, Iain,Tuttle, Tell
-
supporting information
p. 2506 - 2509
(2013/06/27)
-
- In vitro and in vivo investigation of dexibuprofen derivatives for CNS delivery
-
Aim:Dexibuprofen, the S(+)-isomer of ibuprofen, is an effective therapeutic agent for the treatment of neurodegenerative disorders. However, its clinical use is hampered by a limited brain distribution. The aim of this study was to design and synthesize brain-targeting dexibuprofen prodrugs and to evaluate their brain-targeting efficiency using biodistribution and pharmacokinetic analysis.Methods:In vitro stability, biodistribution and pharmacokinetic studies were performed on male Sprague-Dawley rats. The concentrations of dexibuprofen in biosamples, including the plasma, brain, heart, liver, spleen, lung, and kidney, were measured using high pressure lipid chromatography (HPLC). The pharmacokinetic parameters of the drug in the plasma and tissues were calculated using obtained data and statistics.Results:Five dexibuprofen prodrugs that were modified to contain ethanolamine-related structures were designed and synthesized. Their chemical structures were confirmed using 1 H NMR, 13 C NMR, IR, and HRMS. In the biodistribution study, 10min after intravenous administration of dexibuprofen (11.70 mg/kg) and its prodrugs (the dose of each compound was equivalent to 11.70 mg/kg of dexibuprofen) in male Sprague-Dawley rats, the dexibuprofen concentrations in the brain and plasma were measured. The C brain /C plasma ratios of prodrugs 1, 2, 3, 4, and 5 were 17.0-, 15.7-, 7.88-, 9.31-, and 3.42-fold higher than that of dexibuprofen, respectively (P0.01). Thus, each of the prodrugs exhibited a significantly enhanced brain distribution when compared with dexibuprofen. In the pharmacokinetic study, prodrug 1 exhibited a brain-targeting index of 11.19 {DTI=(AUC brain /AUC plasma) 1 /(AUC brain /AUC plasma) dexibuprofen }.Conclusion:The ethanolamine-related structures may play an important role in transport across the brain blood barrier.
- Xuan, Zhang,Xing, Liu,Tao, Gong,Xun, Sun,Zhang, Zhi-Rong
-
experimental part
p. 279 - 288
(2012/07/01)
-
- SYNTHESIS OF HYDROXYALKYL AMIDES FROM ESTERS
-
Hydroxyamides are synthesized from esters. A process of making hydroxyalkyl amides comprises: reacting an ester with a hydroxyalkyl amine having the formula H2N—R3—OH wherein R3 is a substituted or unsubstituted C2 to C5 alkyl, in the presence of a catalyst in an anhydrous solution to form the hydroxyalkyl amides. Monomers suitable for formation of polymeric articles can utilize these hydroxyamides.
- -
-
Page/Page column 3
(2012/11/08)
-
- Photoswitchable organocatalysis: Using light to modulate the catalytic activities of N-heterocyclic carbenes
-
A 4,5-dithienylimidazolium salt was found to undergo electrocyclic isomerization upon exposure to UV radiation (λirr = 313 nm) under neutral and basic conditions; subsequent exposure to visible light reversed the reaction. Under ambient light and in the presence of base, the imidazolium species catalyzed transesterifications as well as amidations in a manner similar to those of previously reported N-heterocyclic carbene precatalysts. However, upon UV irradiation to effect the aforementioned photocyclization, the rate of the transesterification reaction between vinyl acetate and allyl alcohol was significantly attenuated (kvis/UV = 12.5), as was the rate of the condensation of ethyl acetate with aminoethanol (kvis/UV = 100). The rates of these reactions were successfully toggled between fast and slow states by alternating exposure to visible and UV light, respectively, thus demonstrating a rare example of a photoswitchable catalyst that operates via photomodulation of its electronic structure.
- Neilson, Bethany M.,Bielawski, Christopher W.
-
supporting information; experimental part
p. 12693 - 12699
(2012/09/05)
-
- Polymer-mounted N3=P(MeNCH2CH2) 3N: A green, efficient and recyclable catalyst for room-temperature transesterifications and amidations of unactivated esters
-
Merrifield resin-supported N3P(MeNCH2CH 2)3N shows excellent activity in the transesterification of higher esters such as glyceryl tribenzoate to methyl esters. The catalyst was successfully cycled 20 times (albeit with an increase in reaction time) without compromising yield up to the 20th cycle. The catalyst also showed good performance in amidation reactions of unactivated esters with amino alcohols.
- Chintareddy, Venkat Reddy,Ho, Hung-An,Sadow, Aaron D.,Verkade, John G.
-
experimental part
p. 6523 - 6529
(2011/12/21)
-
- Highly efficient and versatile acetylation of alcohols, phenols and amines catalyzed by methylenediphosphonic acid (MDP) under solvent-free conditions
-
Methylenediphosphonic Acid (MDP) was found to be a simple, cheap and reusable heterogeneous catalyst for the acetylation of structurally diverse alcohols, phenols and amines with acetic anhydride under solvent-free conditions at room temperature. This method showed preferential selectivity for the acetylation of the amino group in the presence of hydroxyl group. The method is very mild and the yields were in excellent.
- Xie, Minhao,Wang, Hongyong,Wu, Jun,He, Yongjun,Liu, Yaling,Zou, Pei
-
experimental part
p. 884 - 886
(2012/04/23)
-
- Air-stable titanocene bis(perfluorooctanesulfonate) as a new catalyst for acylation of alcohols, phenols, thiols, and amines under solvent-free condition
-
Air-stable titanocene bis(perfluorooctanesulfonate) [Cp2Ti(OSO2C8F17)2] that shows high Lewis acidity was prepared from Cp2TiCl2 and AgOSO2C8F17. The compound was characterized by different techniques, and examined as a catalyst for acylation reactions. It was found that using equimolar acetic anhydride as acetylating agent and under solvent-free condition, Cp2Ti(OSO2C8F17)2 exhibits high activity and selectivity in the acetylation of various alcohols, phenols, thiols, and amines. Also, good catalytic efficiency is observed in the acylation of 2-phenylethanol across various acylating reagents. The catalyst can be reused without loss of activity in a test of ten cycles. The Cp2Ti(OSO2C8F17)2 catalyst affords a simple, efficient and general method for the acylation of alcohols, phenols, thiols, and amines.
- Qiu, Renhua,Zhang, Guoping,Ren, Xiaofang,Xu, Xinhua,Yang, Ronghua,Luo, Shenglian,Yin, Shuangfeng
-
experimental part
p. 1182 - 1188
(2010/06/13)
-
- Metal acetate/metal oxide in acetic acid: An efficient reagent for the chemoselective N-acetylation of amines under green conditions
-
The use of catalytic amount of metal acetate or metal oxide in acetic acid is a new and highly efficient acetylating system for chemoselective N-acetylation of primary and secondary amines in excellent yields under reflux condition. No other solvent is required. The noted features of this method include mild reaction conditions, use of innocuous reagents, excellent yields, convenient work-up, and reuse of catalyst.
- Brahmachari, Goutam,Laskar, Sujay,Sarkar, Sajal
-
experimental part
p. 288 - 295
(2010/10/18)
-
- Chemoselective acylation of amines, thiols and phenols using 2,4,6-triacyloxy-1,3,5-triazine (TAT) as a new and effective reagent under mild condition
-
A facile chemoselective acylation of amines, thiols and phenols using 2,4,6-triacyloxy-1,3,5-triazine (TAT) under mild condition is described. New reagent, high product yield, short reaction time, ease of operation and solvent free reaction condition is the most acceptable feature of the present method.
- Gholap, Somnath S.,Tambe, Ganesh B.,Gill, Charansingh H.
-
experimental part
p. 179 - 182
(2010/04/05)
-
- SO42-/SnO2: Efficient, chemoselective, and reusable catalyst for acylation of alcohols, phenols, and amines at room temperature
-
SO42-/SnO2 was employed for the acylation of a variety of alcohols, phenols, and amines under solvent-free conditions at room temperature. This method showed preferential selectivity for acetylation of the amino group in the presence of a hydroxyl group. The reported method is simple, mild, and environmentally viable, using several other acid anhydrides at room temperature. Copyright Taylor & Francis Group, LLC.
- Satam, Jitendra R.,Gawande, Manoj B.,Deshpande, Sameer S.,Jayaram, Radha V.
-
p. 3011 - 3020
(2008/02/12)
-
- 2,3,4,5-TETRAHYDRO-1H-1,5-BENZODIAZEPINE DERIVATIVE AND MEDICINAL COMPOSITION
-
The present invention has its object to provide a 2,3,4,5-tetrahydro-1H-1,5-benzodiazepine derivative represented with the Formula (1) , or the pharmaceutically acceptable salt, which is effective as a therapeutic and prophylactic agent for diabetes, diabetic nephropathy, or glomerulosclerosis.
- -
-
-
- Generation of cyclic ketene-N,X-acetals (X = O, S) from 2-alkyl-1,3-oxazolines and 2-alkyl-1,3-thiazolines. Reactions with acid chlorides, 1,3-diacid chlorides and N-(chlorocarbonyl) isocyanate
-
2-Alkyl-1,3-oxazolines, 2-alkyl-1,3-thiazolines, and the corresponding cyclic ketene-N,X-acetals (X = O, S) derived from them were reacted with monoacid chlorides, diacid chlorides, triacid chlorides. A series of these carbon-carbon bond-forming reactions and cyclizations to both substituted 2,3-dihydrooxazolo[3,2-a]pyridine-5,7-diones and 2,3-dihydrothiazolo[3,2-a] pyridine-5,7-diones proceeded under mild reaction conditions. Cyclic ketene-N,X-acetal intermediates play important roles in all these reactions. Related cyclizations with N-(chlorocarbonyl) isocyanate formed substituted 2,3-dihydrooxazolo[3,2-c]pyrimidine-5,7-diones and 2,3-dihydrothiazolo[3,2-c] pyrimidine-5,7-diones. Georg Thieme Verlag Stuttgart.
- Zhou, Aihua,Pittman Jr., Charles U.
-
-
- N-heterocyclic carbene-catalyzed amidation of unactivated esters with amino alcohols
-
(Chemical Equation Presented) A catalytic amidation of unactivated esters with amino alcohols is described. A series of solution studies in addition to the first X-ray structure of a carbene-alcohol complex support a carbene-base nucleophile activation mechanism.
- Movassaghi, Mohammad,Schmidt, Michael A.
-
p. 2453 - 2456
(2007/10/03)
-
- USE OF CERTAIN N-ACYLETHANOLAMINES TO ACHIEVE ETHYLENE- AND CYTOKININ-LIKE EFFECTS IN PLANTS AND FUNGI
-
N-acylethanolamines (NAEs) that can deliver an ethylene- or cytokinin-like effects to a plant, plant part or fungus are disclosed. Also disclosed are methods of using the NAES.
- -
-
-
- Efficient chemoselective liquid phase acylation of amines, alcohols and bifunctional compounds over ZSM-35
-
ZSM-35, is a medium pore zeolite, has been synthesized using ethylene diamine as organic template. The catalyst is used in the acylation of different amines, alcohols and bifunctional compounds. This material is found to be active and selective acid catalyst, exhibits not only very good activity but also very high chemo-selectivity towards monoacylation of bifunctional compounds. This material is more reactive for smaller organic compounds because of its pore dimension. In case of bifunctional compounds like amino alcohols, amines are selectively acylated at lower temperature.
- Srivastava,Venkatathri
-
p. 888 - 891
(2007/10/03)
-
- Chemoselective acylation of amines in aqueous media
-
Amines are efficiently acylated by both cyclic and acyclic anhydrides by dissolving them in an aqueous medium with the help of a surfactant, sodium dodecyl sulfate (SDS). Cyclic and acyclic anhydrides react with equal ease with an amine, and amines with various stereo-electronic factors react at the same rates with an anhydride. Chemoselective acylation of amines in the presence of phenols and thiols and of thiols in the presence of phenols has been achieved. No acidic or basic reagents are used during the reaction. No Chromatographic separation is required for isolation of the acylated products. Reactions in a neutral aqueous medium, easy isolation of products, and innocuous by-products make the present method a green chemical process. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Naik, Sarala,Bhattacharjya, Gitalee,Talukdar, Bandana,Patel, Bhisma K.
-
p. 1254 - 1260
(2007/10/03)
-
- Structure-reactivity correlation in the aminolysis of 4-fluorophenyl acetate in aqueous medium
-
The reaction of the title substrate with a series of amines of varying pKa, viz. ammonia, ethanolamine, glycine, 1,2-diaminopropane, 1,3-diaminopropane, n-butylamine, piperidine, hydrazine, imidazole, and hydroxylamine is subjected to a kinetic study in aqueous medium, 25°C, ionic strength 0.1 M (KCl). Pseudo-first-order rate coefficients (kobs) are found throughout under amine excess at various pH values for each amine. For amines, excluding hydrazine, ammonia, and hydroxylamine the reaction follows clean second-order kinetics and the plots of (kobs - kH) against free amine concentration are linear at constant pH. The macroscopic nucleophilic substitution rate coefficients (kN) are obtained as the slopes of these plots and found to be pH independent. For hydrazine, ammonia, and hydroxylamine, a rate dependence on more than first power of the amine is observed, accordingly, the rate constants for the assisted paths have been disseminated for these amines besides kN. The Broensted-type plot (logkN against amine pKa) is linear with a slope value of β = 1.02. The magnitude of the slope value is consistent with a stepwise mechanism through a zwitterionic tetrahedral addition intermediate whose breakdown to products is rate-determining (k2 step). A remarkable reactivity difference is observed among the diamines, the reason for which is discussed in detail.
- Rajarathnam,Jeyakumar,Ananthakrishna Nadar
-
p. 366 - 373
(2007/10/03)
-
- Yttria-zirconia based Lewis acid: An efficient and chemoselective catalyst for acylation reactions
-
Yttria-zirconia based strong Lewis acid efficiently catalyzes acylation of alcohols, amines and thiols under environmentally safe, heterogeneous reaction conditions with high selectivity and in excellent yields.
- Kumar,Pandey,Bodas,Dongare
-
p. 206 - 209
(2007/10/03)
-
- Linear Bronsted-type behavior in the aminolysis of substituted naphthyl acetates
-
The reactions of 4-acetyl-1-naphthyl acetate (1) and 6-acetyl-2-naphthyl acetate (2) with a series of amines of varying pKa, viz. morpholine, ammonia, ethanolamine, glycine, n-butylamine, piperidine, hydrazine, imidazole, and hydroxylamine, are subjected to a kinetic investigation in aqueous medium, 30 °C, ionic strength 0.1 M (KCl). Pseudo-first-order rate coefficients (kobs) are found under amine excess. The plots of (kobs-kH) against free amine concentration are linear at constant pH. The macroscopic nucleophilic substitution rate coefficients (kN) are obtained as the slopes of these plots and found to be pH-independent for all the amines employed. The Bronsted-type plots obtained (log kN against amine pKa) for the aminolysis of both esters 1 and 2 are linear with slope values of β = 0.74 and β = 0.94, respectively. From these values, the kinetic law and the analysis of products, it is deduced that for both esters aminolysis proceed through a zwitterionic tetrahedral addition intermediate (T±) whereby its dissociation into products is rate-limiting (k2 step). Comparison of kN values among them shows that both esters follow an identical mechanistic pathway with 1 having higher reactivity than 2, the reasons for which are discussed.
- Rajarathnam,Ananthakrishna Nadar
-
p. 157 - 164
(2007/10/03)
-
- Highly selective acylation of alcohols and amines by an indium triiodide-catalysed transesterification process
-
A very simple method has been developed for the acylation of alcohols and amines by ethyl acetate through an indium triiodide-catalysed transesterification process. Using this method acylation of a primary OH group in the presence of secondary and phenolic OH groups, and of a primary NH2 in the presence of secondary NH and primary OH have been achieved with high selectivity. The Royal Society of Chemistry 2000.
- Ranu, Brindaban C.,Dutta, Pinak,Sarkar, Arunkanti
-
p. 2223 - 2225
(2007/10/03)
-
- Reactions of Hydroxy Carboxylic Acid Amides and Their O-Trimethylsilyl Derivatives with Chloro(chloromethyl)-dimethylsilane. Synthesis of 1-Oxa-4-aza-2-sila-and 1-Oxa-4-aza-2,6-disilacyclohexanes
-
A general strategy has been developed for the synthesis of 1-oxa-4-aza-2-silacyclohexanes, 1-oxa-4-aza-2-silacyclohexan-5-ones, and 4-acyl-1-oxa-4-aza-2-silacyclohexanes from carboxylic acid amides containing a hydroxy group in the acid and/or amide moiety via two routes. The first of these includes transformation of N-monosubstituted carboxamides into corresponding O-trimethylsilyl derivatives which react with chloro(chloromethyl)dimethylsilane in the presence of a base to form unstable N-chlorodimethylsilyl-methyl amide derivatives with a five-coordinate silicon atom. Thermal decomposition of the latter during fractionation yields the target silicon-containing heterocycles with an OSiCH2N fragment. The second route consists of direct treatment of N-monosubstituted carboxamides with a mixture of hexamethyldisilazane and chloro(chloromethyl)dimethylsilane, which results in formation of 1-oxa-4-aza-2-silacyclohexan-5-ones and 4-acyl-1-oxa-4-aza-2-silacyclohexanes in high yields, thus excluding preliminary O-silylation of the starting hydroxy amides. One-pot reactions of N-unsubstituted carboxylic acid amides with a hexamethyldisilazane-chloro(chloromethyl)dimethylsilane mixture, followed by hydrolysis, yield 4-acyl-1-oxa-4-aza-2,6-disilacyclohexanes.
- Baukov,Shipov,Kramarova,Mamaeva,Zamyshlyaeva,Anisimova,Negrebetskii
-
p. 1216 - 1228
(2007/10/03)
-
- A Mild and Efficient Method for Selective Acetylation of Amines
-
Primary and secondary amines were acetylated under mild conditions by means of 3-acetyl-1,3-thiazolidine-2-thione .The reaction was successfully applied to selective acetylation of a primary amino group of diamines containing a primary and a secondary amino groups or exclusive N-acetylation of amino alcohols.Key Words Selective acetylation; 3-Acetyl-1,3-thiazolidine-2-thione.
- Yang, Shyh-Chyun,Wang, Huey-Min,Chen, Ling-Ching
-
p. 585 - 588
(2007/10/02)
-
- Convenient and selective acetylations of phenols, amines and alcohols
-
Two convenient methods have been developed for selective acetylation. In method 1, phenols and amines are selectively acetylated in the presence of alcohols by acetic anhydride in a biphasic aqueous NaOH-isopropanol mixture. In method 2, alcoholic group is acetylated in the presence of amino functions using a strong acidic resin.
- Srivastava,Tandon,Ray
-
p. 2703 - 2710
(2007/10/02)
-
- Research on radioprotective agents: Δ-2 Thiazolines and homologous derivatives
-
Compounds derived from Δ-2 thiazoline, Δ-2 thiazolinium iodoalkylate and 4,5-dihydro-1,3 thiazine have been prepared and evaluated as potential antiradiation agents in mice. They generally have a low toxicity and significant radioprotective activity.
- Robbe,Fernandez,Chapat,et al.
-
-
- N-ALKYLATION OF ACETAMIDE
-
The possibility of the N-alkylation of acetamides by alkyl halides in the presence of potassium fluoride was demonstrated.The yield of the product increases with the addition of catalytic amounts of a quartenary ammonium salt.N-Alkylation also take place in the presence of powdered alkali in aprotic solvents.The alkylation of acetamide was also realized with ethylene chlorohydrin in the presence of an equimolar amount of pyridine.
- Torosyan, G. O.,Tagmazyan, N. K.,Babayan, A. T.
-
p. 456 - 459
(2007/10/02)
-
- Paraphenylenediamines substituted at position 2 of the benzene ring
-
Dye, especially for human hair that consists of the new chemical compounds of the general formula STR1 in which Z is selected in the group consisting of hydroxyalkyl, alkoxyalkyl, acylaminoalkyl, carbalkoxyaminoalkyl, mesylaminoalkyl, ureidoalkyl, aminoalkyl, monoalkylaminoalkyl, dialkylaminoalkyl radicals, and the salts of the corresponding acids. Among the preferred acid salts are the sulfates, hydrochlorides, phosphates and tartrates. This dye is particularly suited for use with metadiphenols, metaphenylenediamines, metaaminophenols as well as the couplers of the formula STR2 in which R3 and R4 are identical or different and may represent hydrogen, alkoxy, or alkyl and in which R5 is selected from the group consisting of acyl, carbalkoxy and ureido.
- -
-
-
- Hair dye compositions and new compounds useful therein
-
Novel compounds of the general formula STR1 wherein Z represents a substituted lower alkyl radical; each of R1 and R2 is hydrogen atom, a lower alkyl or a substituted lower alkyl identical with or different from Z and the functional groups NO2 and NR1 R2 can occupy all ring positions in relation to OZ, with the exception that if Z is β-hydroxyethyl, --NO2 is in the 4 position and --N(R1)(R2) is in the 2 position then either R1 or R2 is other than hydrogen. The novel compounds are for dyeing human hair in a variety of yellow shades. The compounds of formula (I) may be used as aqueous or water-alcohol solutions to form dye compositions for dyeing human hair.
- -
-
-
- Transformation of DAEP under Various Oxidative Conditions
-
14C-DAEP was subjected to four different oxidative conditions, and the products were identified.On peracid oxidation in dichloromethane, DAEP gave the oxon (1) predominantly, and 2-acetylaminoethyl dimethoxyphosphinyl disulphide (3), N-acetylcysteamine (10), its oxidized dimer (11) and a further oxidation product of compound (11).This indicates that an unstable phosphorus oxythionate was initially formed, which lost sulfur, was rearranged, and hydrolyzed to give these products.Under other conditions, phosphinyl disulfide 3 was not found.DAEP was metabolized in vitro with a rat liver microsome-NADPH system via oxydation.The aqueous reaction condition prevented the formation of compound 3 from the intermediate, which predominated as well as the oxon formation under anhydrous or close conditions.The formation of various products with sunlight irradiation on glass plates or on bean leaves could be interpreted by oxidation at P=S, C1 and C2 positions, demethylation, and deacetylation, followed by further transformation.The initial formation of phosphorus oxythionate seems to play an important role in the oxidation of the organothionophosphorus compound.
- Miyamoto, Toru,Yamamoto, Izuru
-
p. 1991 - 1998
(2007/10/02)
-
- Transacylations with Acyl Derivatives of 4-Pyridones
-
Aliphatic and aromatic amines as well as thiols react with N-acyl-4-pyridones (2a, b) and with 4-(benzoyloxy)pyridine (3a) in methylene chloride or chloroform to give the N-substituted amides 4-6 and the thiol esters 7 and 8, respectively, with very good yields.Primary and secondary alcohols react more slowly, tert-butyl alcohol only with 3a to the tert-butyl esters 12 under basic catalysis or with the much more reactive N-(trihaloacetyl)-4-pyridones 3b, c.N-Acetyl-4-pyridone (2a) possesses a much higher acylation potential than N-acetylimidazole (13a).
- Effenberger, Franz,Bessey, Eberhard
-
p. 2100 - 2109
(2007/10/02)
-
- Dyeing composition for keratinic fibers containing paraphenylenediamines
-
Dye compositions, especially for human hair containing the new chemical compounds of the general formula STR1 in which formula the radical Z is selected in the group formed by the hydroxyalkyl, alkoxyalkyl, acylaminoalkyl, carbalkoxyaminoalkyl, mesylaminoalkyl, ureidoalkyl, aminoalkyl, monoalkylaminoalkyl, dialkyl-aminoalkyl radicals, and the salts of the corresponding acids. Among the preferred acid salts, the sulfates, hydrochlorides, phosphates and tartrates may be mentioned. This dye is particularly suited for use with a coupler of the formula STR2 in which formula R3 and R4 are identical or different and may represent a hydrogen atom, alkoxy radical, or an alkyl radical and in which R5 is a radical selected in the group formed by the acyl, carbalkoxy and ureido radicals.
- -
-
-