109-85-3Relevant academic research and scientific papers
Lack of effect of the length of oligoglycine- and oligo(ethylene glycol)-derived para-substituents on the affinity of benzenesulfonamides for carbonic anhydrase II in solution
Jain, Ahamindra,Huang, Shaw G.,Whitesides, George M.
, p. 5057 - 5062 (1994)
Using 1H NMR spectroscopy, values of T2 have been determined for the methylene protons of the oligoglycine moieties of para-substituted benzenesulfonamides having structures H2NO2SC6H4CO(Gly)(n)OH (n = 1-6) bound at the active site of bovine carbonic anhydrase II (CA, EC 4.2.1.1). These values have been correlated with measurements of dissociation constants of these complexes, in order to infer motion of these ligands when bound to the enzyme. Motion of glycines 1-3 (those closest to the aryl ring) is hindered by their proximity to the protein; motion of glycines 4-6 is relatively unhindered. Despite the restriction to motion inferred for glycines 1-3, the values of K(d) for the six compounds (n = 1-6, 1-6) are indistinguishable within experimental uncertainty (± 20%): K(d) in μM (n) 0.30 (1); 0.26 (2); 0.33 (3); 0.37 (4); 0.37 (5); 0.34 (6). There is, therefore, an unexpected compensation of the loss in conformational entropy on binding by another contributor to the free energy.
Platinum-Triggered Bond-Cleavage of Pentynoyl Amide and N-Propargyl Handles for Drug-Activation
Oliveira, Bruno L.,Stenton, Benjamin J.,Unnikrishnan,De Almeida, Cátia Rebelo,Conde, Jo?o,Negr?o, Magda,Schneider, Felipe S.S.,Cordeiro, Carlos,Ferreira, Miguel Godinho,Caramori, Giovanni F.,Domingos, Josiel B.,Fior, Rita,Bernardes, Gon?alo J. L.
, p. 10869 - 10880 (2020)
The ability to create ways to control drug activation at specific tissues while sparing healthy tissues remains a major challenge. The administration of exogenous target-specific triggers offers the potential for traceless release of active drugs on tumor sites from antibody-drug conjugates (ADCs) and caged prodrugs. We have developed a metal-mediated bond-cleavage reaction that uses platinum complexes [K2PtCl4 or Cisplatin (CisPt)] for drug activation. Key to the success of the reaction is a water-promoted activation process that triggers the reactivity of the platinum complexes. Under these conditions, the decaging of pentynoyl tertiary amides and N-propargyls occurs rapidly in aqueous systems. In cells, the protected analogues of cytotoxic drugs 5-fluorouracil (5-FU) and monomethyl auristatin E (MMAE) are partially activated by nontoxic amounts of platinum salts. Additionally, a noninternalizing ADC built with a pentynoyl traceless linker that features a tertiary amide protected MMAE was also decaged in the presence of platinum salts for extracellular drug release in cancer cells. Finally, CisPt-mediated prodrug activation of a propargyl derivative of 5-FU was shown in a colorectal zebrafish xenograft model that led to significant reductions in tumor size. Overall, our results reveal a new metal-based cleavable reaction that expands the application of platinum complexes beyond those in catalysis and cancer therapy.
HYDROLYSIS OF N-SALICYLIDENE-2-METHOXYETHYLAMINE. INTRAMOLECULAR GENERAL BASE CATALYSIS AND SPECIFIC EFFECTS OF BORIC ACID.
Nagamatsu,Okuyama,Fueno
, p. 2502 - 2507 (1984)
Hydrolysis of N-salicylidene-2-methoxyethylamine is kinetically investigated at 30 degree C. Intramolecular general base catalysis by the o-O** minus substituent takes place in the neutral pH region. Nucleophilic catalysis by morpholine was also found to be operative. Added boric acid accelerates the hydrolysis above pH 5. 5 while it decelerates the hydrolysis below pH 5. 5. The hydrolysis rate as the function of the boric acid concentration follows a saturation curve in harmony with a reaction sequence involving a rapid equilibrium formation of a borate-substrate complex followed by its breakdown. The morpholine catalysis is inhibited by boric acid in accord with the slow reaction of morpholine with the complex.
Nucleophilic Catalysis of Hydrolysis of a Schiff Base by Amines. Intramolecular Catalysis of Transimination
Okuyama, Tadashi,Nagamatsu, Hiroaki,Kitano, Masakazu,Fueno, Takayuki
, p. 1516 - 1521 (1986)
Certain groups of amines were found to catalyze hydrolysis of N-(o-methoxybenzylidene)-2-methoxyethylamine through transimination.The rate-determining transimination was followed by rapid hydrolysis of an intermediate Schiff base.Rate constants for the transimination with simple, but less basic, amines change sigmoidally with pH and are buffer-dependent in accord with a mechanism involving a trapping of the incipient tetrahedral intermediate T+1 by a proton transfer to acids or bases.Morpholine behaved similarly.In the reaction with bifunctional amines carrying an internal amino group, rates are independent of both pH and buffer concentrations.Initial nucleophilic attack of these amines is rate determining in the whole pH range examined because of the rapid trapping of T+1 by an intramolecular proton transfer.
INFLUENCE OF BORIC ACID ON THE HYDROLYSIS RATE OF A HYDROXY SCHIFF BASE.
Matsuda,Nagamatsu,Okuyama,Fueno
, p. 500 - 505 (1984)
Effects of boric acid on the rate of hydrolysis of a Schiff base derived from alpha -hydroxyisobutyrophenone and 2-methoxyethylamine were examined in the pH range 4. 2-10. 4 at 30 degree C. The rate increased above pH 7 but decreased below pH 7 with increasing borate concentration following a saturation curve. This is consistent with a reaction sequence involving a preequilibrium formation of a borate-substrate complex followed by its rate-determining decay to the hydrolysis products. The formation constant of the complex showed a bell-shaped change with pH but the rate constant for the complex decay was constant above pH 7, a small change being observed at lower pH. A mechanism involving an intramolecular transfer of the boron-coordinated hydroxide ion to the imine carbon within the complex is presented.
Simple and efficient: Ethylene glycol isonitrile gold(I) chlorides for the formation and stabilization of gold nanoparticles
Tuchscherer, Andre,Schaarschmidt, Dieter,Schulze, Steffen,Hietschold, Michael,Lang, Heinrich
, p. 4421 - 4428 (2011)
Ethylene glycol isonitriles C≡N(CH2CH2O) nCH3 (5a, n = 1; 5b, n = 3; 5c, n = 4) with different chain lengths were prepared by using straightforward synthesis methodologies including the Gabriel synthesis and an Appel-type reaction protocol. Upon treatment with [AuCl(SMe)2], compounds 5a-c gave the corresponding isocyanide gold(I) chlorides [AuCl{C≡N(CH2CH2O) nCH3}] (7a, n = 1; 7b, n = 3; 7c, n = 4). Single-crystal X-ray diffraction studies reveal a polymeric (7a) or dimeric (7c) structure with aurophilic interactions. Gold(I) complexes 7a-c were applied in the formation and stabilization of gold nanoparticles (AuNPs). The isonitriles with their ethylene glycol functionalities, which provide multiple donating capabilities, are able to stabilize the encapsulated gold colloids. The reduction of 7a-c by the addition of Na[BH4] in tetrahydrofuran or methanol produces AuNPs without the further addition of any stabilizer, since metal-organic 7a-c combine the stabilizing component and gold source in one molecule. The dependency of different solvents, concentrations, and varying ethylene glycol chain lengths on the NP size and size distribution is reported. Characterization by TEM, UV/Vis spectroscopy, and XRPD revealed that AuNPs are formed with a size between 6.4(±1.4) to 9.5(±2.3) nm in methanol and 18.2(±2.3) to 27.2(±3.5) nm in tetrahydrofuran. Copyright
Indirect reduction of CO2and recycling of polymers by manganese-catalyzed transfer hydrogenation of amides, carbamates, urea derivatives, and polyurethanes
Liu, Xin,Werner, Thomas
, p. 10590 - 10597 (2021/08/20)
The reduction of polar bonds, in particular carbonyl groups, is of fundamental importance in organic chemistry and biology. Herein, we report a manganese pincer complex as a versatile catalyst for the transfer hydrogenation of amides, carbamates, urea derivatives, and even polyurethanes leading to the corresponding alcohols, amines, and methanol as products. Since these compound classes can be prepared using CO2as a C1 building block the reported reaction represents an approach to the indirect reduction of CO2. Notably, these are the first examples on the reduction of carbamates and urea derivatives as well as on the C-N bond cleavage in amides by transfer hydrogenation. The general applicability of this methodology is highlighted by the successful reduction of 12 urea derivatives, 26 carbamates and 11 amides. The corresponding amines, alcohols and methanol were obtained in good to excellent yields up to 97%. Furthermore, polyurethanes were successfully converted which represents a viable strategy towards a circular economy. Based on control experiments and the observed intermediates a feasible mechanism is proposed.
Preparation method of 2-methoxyethylamine
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Paragraph 0029-0061, (2021/05/08)
The invention relates to a preparation method of 2-methoxyethylamine in the technical field of organic synthesis chemical industry. The preparation method comprises the following steps: dissolving N,N'-bis(2-methoxyethyl)thiourea as an initial raw material in a solvent, and carrying out an oxidation reaction in the presence of an oxidant to prepare 2-methoxyethylamine. The method provided by the invention has the advantages of short route steps, mild conditions and high product yield, and provides a universal new method for preparation of 2-methoxyethylamine.
Synthesis of oxalamides by acceptorless dehydrogenative coupling of ethylene glycol and amines and the reverse hydrogenation catalyzed by ruthenium
Ben-David, Yehoshoa,Diskin-Posner, Yael,Milstein, David,Zhou, Quan-Quan,Zou, You-Quan
, p. 7188 - 7193 (2020/07/23)
A sustainable, new synthesis of oxalamides, by acceptorless dehydrogenative coupling of ethylene glycol with amines, generating H2, homogeneously catalyzed by a ruthenium pincer complex, is presented. The reverse hydrogenation reaction is also accomplished using the same catalyst. A plausible reaction mechanism is proposed based on stoichiometric reactions, NMR studies, X-ray crystallography as well as observation of plausible intermediates.
Method for preparing 2-methoxyethylamine through direct catalytic amination of ethylene glycol monomethyl ether
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Paragraph 0028-0039; 0040-0043, (2019/05/08)
The invention discloses a method for preparing 2-methoxyethylamine through direct catalytic amination of ethylene glycol monomethyl ether. The method comprises the following steps: continuously inputting raw materials such as ethylene glycol monomethyl ether, ammonia and hydrogen into a tubular fixed bed reactor filled with a catalyst and directly performing amination reaction to prepare the 2-methoxyethylamine. The catalyst takes gamma-aluminum oxide as a carrier; the loaded active metal components are one or a mixture of any of copper, cobalt, nickel, chromium, cerium, silver or ruthenium; and the theoretical load quantity of the active components is 15 to 35 percent of the mass of the catalyst. The method provided by the invention has the advantages of simple process, mild reaction conditions, high yield of 2-methoxyethylamine, low cost and the like.
