- Hydroxamic acid and preparation method of hydroxamic acid salt
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The invention discloses a preparation method of hydroxamic acid salt. The preparation method comprises the following steps: mixing organic carboxylic ester, hydroxylamine or/and hydroxylamine salt, acatalyst and an inert solvent; and adding alkali and grinding to obtain the hydroxamic acid salt, and adding acid into the hydroxamic acid salt, grinding, centrifuging or filtering to obtain the hydroxamic acid. The process conditions for producing the hydroxamic acid or the hydroxamic acid salt by a grinding method in the prior art are optimized, the inert solvent diesel oil is used for replacingwater or methanol and the inert solvent is recycled after being subjected to centrifugal separation and simple treatment so that the generation of waste liquid is avoided, the use of toxic solvents is avoided and the operation safety is also greatly improved; besides, the material is in a flowing state during the grinding reaction due to the use of the inert solvent,so that the viscous material is prevented from adhering to the inner wall of the reaction container and the grinding medium, the reaction is more uniform, the temperature is more controllable, the reaction efficiency is greatly improved, the discharging is more convenient and the industrial production is facilitated.
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Paragraph 0073-0075
(2020/04/06)
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- Method for synthesizing hydroximic acid compound
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The invention discloses a method for synthesizing a hydroximic acid compound. The method comprises the step of subjecting an organic carboxylic acid compound with a structure represented by a formula(I) shown in the description and a hydroxylamine compound with a structure represented by a formula (II) shown in the description to a grinding reaction in the presence of a coupling reagent, therebypreparing the hydroximic acid compound with a structure represented by a formula (III) shown in the description. According to the method, the technical problems that a large amount of organic solventis used, the reaction temperature is high, wastes are plenty, the aftertreatment is complicated, environmental protection is adverse and the like are solved, and the method has the advantages that thesource of the raw materials is wide, the cost is low, the operation is simple, the efficiency is high, the product is easy to separate, the yield is high, industrial production is easy to achieve andthe like.
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Paragraph 0083-0086
(2019/06/13)
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- Photoinduced one-pot synthesis of hydroxamic acids from aldehydes through in-situ generated silver nanoclusters
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Hydroxamic acids have attracted significant attention due to their widespread use in applied chemistry. In this report, a modified Angeli–Rimini method has been achieved via the visible light-mediated catalytic transformation of a variety of heterocyclic, aromatic and aliphatic aldehydes 1a–j to their corresponding hydroxamic acids 2a–j in 81–93% yield. The unique ability of vitamin K3 as a photoredox catalyst to expedite the development of completely new reaction mechanisms and to enable the construction of challenging carbon–nitrogen bonds has been investigated. It is shown for the first time that the vitamin K3 and aldehyde are largely responsible for rapid in situ reduction of Ag+ ions to catalytic photoluminescent Ag nanoclusters that possess a bandgap energy of 2.87?eV and are less than 2 nm in size. A mechanism for this reaction has been proposed and is supported by UV–Vis, TEM, ESI/MS, FT-IR, 1H NMR and 13C NMR analyses. The investigated method utilizes readily available reagents and produces the hydroxamic acids in high yields without the formation of side products, making it simple, practical and cost-effective.
- Mohamed, Yasser M. A.,Attia, Yasser A.,Solum, Eirik Johansson
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p. 7173 - 7186
(2018/08/17)
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- Synthesis and biological activity of salinomycin-hydroxamic acid conjugates
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Several salinomycin-hydroxamic acid conjugates were designed and synthesized. Most conjugates showed better antiproliferative activities than salinomycin in HT-29 colon cancer, HGC-27 gastric cancer, and especially in MDA-MB-231 triple-negative human breast cancer cells. These conjugates are stable in cell culture media, and they showed much better biological activities than the 1:1 physical mixture with hydroxamic acids and salinomycin. The better membrane permeability and hydrolysis rate of the conjugates may lead to the activity improvements.
- Li, Bo,Wu, Jun,Zhang, Wenxuan,Li, Zhongwen,Chen, Gang,Zhou, Qi,Wu, Song
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p. 1624 - 1626
(2017/03/16)
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- Benzoic hydroxamate-based iron complexes as model compounds for humic substances: Synthesis, characterization and algal growth experiments
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A series of monomeric and dimeric FeIII complexes bearing benzoic hydroxamates as O,O-chelates has been prepared and characterized by elemental analysis, IR spectroscopy, UV-Vis spectroscopy, electrospray ionization mass spectrometry (ESI-MS), cyclic voltammetry, EPR spectroscopy and for some examples by X-ray diffraction analysis. The stability of the synthesized complexes in pure water and seawater was monitored over 24 h by means of UV-Vis spectrometry. The ability to release iron from the synthesized model complexes has been investigated with algae growth experiments.
- Orlowska, Ewelina,Roller, Alexander,Wiesinger, Hubert,Pignitter, Marc,Jirsa, Franz,Krachler, Regina,Kandioller, Wolfgang,Keppler, Bernhard K.
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p. 40238 - 40249
(2016/05/24)
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- Chromatography-free, Mitsunobu-triggered heterocyclizations of salicylhydroxamic acids to 3-hydroxybenzisoxazoles
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The Mitsunobu reaction has become one of the most powerful tools to alkylate acidic pronucleophiles. A significant caveat of Mitsunobu chemistry, however, is that the reaction mixture is often plagued with purification problems owing to the phosphine oxide and hydrazine dicarboxylate by-products. In addition to the development of more readily separable Mitsunobu reagents, the product's physicochemical properties may be exploited to facilitate purification. In this regard, we present a swift and efficient preparation of 3-hydroxybenzisoxazoles by the Mitsunobu-triggered heterocyclizations of salicylhydroxamic acids, which can be isolated by an acid–base work-up. As expected, a range of functional groups was compatible with the chemistry.
- Van Eker, Daniel,Chauhan, Jay,Murphy, William A.,Conlon, Ivie L.,Fletcher, Steven
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p. 5301 - 5303
(2016/11/16)
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- Studies of spectral and magnetic behaviour of some complexes of Fe(II) metals with 2-hydroxy benzo-hydroxamic acid
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Some complexes of Fe(II) cations with 2-hydroxy benzo- hydroxamic acid has been prepared separately in aqueous and non-aqueous medium. The general molecular formula of the complexes has been found to be [Fe(L)(B)4], where L= 2-hydroxy benzo-hydroxamic acid and B=bases containing oxygen and nitrogen atoms as their donor sites. On the characterisation of the complexes by usual physico-chemical methods, all the complexes have been found to be nonelectrolyte, monomeric and octahedral in geometry.
- Sudhanshu,Siddique, Irfan Ahmad,Sudhanshu, Sandeep,Kumari, Kamini
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p. 1841 - 1844
(2013/06/27)
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- Synthesis and catalytic epoxidation potential of oxodiperoxo molybdenum(VI) complexes with 2-hydroxybenzohydroxamate and 2-hydroxybenzoate: The crystal structure of PPh4[MoO(O2)2(HBA)]
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(PPh4)2[MoO(O2)2(SHAH)] ·H2O and PPh4[MoO-(O2)2(HBA)] (SHAH3 = 2-hydroxybenzohydroxamic acid and HBAH = 2-hydroxybenzoic acid) have been synthesized and characterized by physico-chemical and spectroscopic methods. In addition, the second complex has been structurally characterized by single-crystal X-ray diffraction analysis. We have compared the catalytic activities of these two new complexes, together with the previously reported PPh4[MoO(O2)2(BZ)] (BZH = benzoic acid), with respect to the epoxidation of alkenes. The hydroxamate complex is the most efficient catalyst among the three complexes, showing excellent catalytic activity for the substrates cyclohexene, cyclooctene, cinnamyl alcohol, pent-4-en-1-ol and hex-1-ene. Springer Science+Business Media B.V. 2010.
- Gharah, Narottam,Chattopadhyay, Basab,Maiti, Swarup K.,Mukherjee, Monika
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experimental part
p. 531 - 539
(2011/11/12)
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- Inhibitors of the FEZ-1 metallo-β-lactamase
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Metallo-β-lactamases (MBLs) catalyze the hydrolysis of β-lactams including penicillins, cephalosporins and carbapenems. Starting from benzohydroxamic acid (1) structure-activity studies led to the identification of selective inhibitors of the FEZ-1 MBL, e.g., 2,5-substituted benzophenone hydroxamic acid 17 has a Ki of 6.1 ± 0.7 μM against the FEZ-1 MBL but does not significantly inhibit the IMP-1, BcII, CphA or L1 MBLs.
- Lienard, Benoit M.R.,Horsfall, Louise E.,Galleni, Moreno,Frere, Jean-Marie,Schofield, Christopher J.
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p. 964 - 968
(2008/12/23)
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- BENZISOXAZOLES
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The present invention concerns the compounds of formula (I), the N-oxide forms, the pharmaceutically acceptable addition salts and the stereochemically isomeric forms thereof, wherein m represents an integer from 1 to 3; X represents amino, hydroxy, -oxo or -Z-R1; Y is absent when X represents -Z-R1 and -(C=O)-R66 when X represents oxo; Z represents carbonyl, -oxy-carbonyl- or -NR 55-carbonyl-; R1 represents C1-4alkyl, Ar1, Ar1-C1-4a1ky1-, -NR3R4 or -Het1; R2 represents hydrogen, halo, nitro, hydroxycarbonyl-, C1-4alkyloxy or C1-4alkyl; R33 and R4 are each independently selected from hydrogen, Ar33 or C1-4alkyl; R5 represents hydrogen, C1-4alkylcarbonyl- or Ar4-carbonyl-; R6 represents a substituent selected from the group consisting of C1.4alkyl, Ar55, Ar6-C1-4alkyl- or NR7R8; R7 and R8 are each independently selected from hydrogen, Het4 or C1-4alkyl; Het1 represents a heterocycle selected from oxazolyl, isoxazolyl, imidazolyl or pyrazolyl wherein said heterocycle is optionally substituted with one, two or three substituents selected from the group consisting of amino, C1-4alkyl, hydroxy-C1-4alkyl, phenyl, phenyl-C1-4alkyl- and phenyl substituted with one or more halo substituents; Het4 represents a heterocycle selected from oxazolyl or isoxazolyl, wherein said heterocycle is optionally substituted with one or more substituents selected from the group consisting of amino, C1-4alkyl, hydroxy-C1-4alkyl-, phenyl, phenyl-Cl-4alkyl and phenyl substituted with one or more halo substituents; and Ar1, Ar2, Ar3, Ar4, Ar5 or Ar6 each independently represents phenyl optionally substituted one or where possible two or more substituents selected from halo, nitro, C1-4alkyl, hydroxy or C1-4alkyloxy-.
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Page/Page column 27
(2010/02/14)
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- PROLINE DERIVATIVES AND USE THEREOF AS DRUGS
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The present invention aims at providing compounds having therapeutic effects due to a DPP-IV inhibitory action, and satisfactory as pharmaceutical products. The present inventors have found that derivatives having a substituent introduced into the γ-position of proline represented by the formula (I) wherein each symbol is as defined in the specification, have a potent DPP-IV inhibitory activity, and completed the present invention by increasing the stability.
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- Hydroxamic acid and its derivatives as inhibitors of melanocyte tyrosinase for topical skin lighteners
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Methods, compounds, and formulations are provided to reduce pigmentation in mammalian skin, comprising hydroxamic acid and its derivatives, and especially benzohydroxamic acid and its derivatives. The compounds preferably inhibit pigment synthesis in melanocytes through inhibition of melanocyte tyrosinase. The methods can be used for lightening skin, and for treating uneven skin complexions, which result from hyperpigmentation-related medical conditions such as melasma, age spots, freckles, ochronosis, and lentigo. The compounds can be used medically or cosmetically, and preferably as topical formulations.
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- Protective solutions for organs
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Described is a protective solution for avoiding ischemic, storage or ischemia/reperfusion to organs, or to isolated cell systems, or to tissue components after perfusion, surgery, transplantation, or cryopreservation and subsequent reperfusion, which contains alkali ions, and if need be also alkaline earth ions as the electrolyte, a buffer e.g. on a histidine derivation basis, as well as a polyol and/or a saccharide, has an osmolarity of about 290 mosm/l to about 350 mosm/l, as well as a pH value of about 6.8 to about 7.4, and to which hydroxamic acid, and/or one or more hydroxamic acid derivatives are added.
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- Naaladase inhibitors for treating retinal disorders and glaucoma
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The present invention relates to pharmaceutical compositions and methods for treating a retinal disorder or glaucoma using NAALADase inhibitors.
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- Intramolecular General Base Catalysis and the Rate-determining Step in the Nucleophilic Cleavage of Ionized Phenyl Salicylate with Primary and Secondary Amines
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The nucleophilic second-order rate constants for the reactions of ionized phenyl salicylate (PS-) with primary and secondary amines have revealed Broensted plots of slopes βnuc1 = 0.52+/-0.06 and βnuc2 = 0.27+/-0.05, respectively.The suggested stepwise reaction mechanism involves the intramolecular proton transfer from cationic nitrogen to the anionic phenolic oxygen to form the monoanionic tetrahedral addition intermediate as the rate-determining step.The low value of βnuc2 is attributed to the extensive of proton transfer in the late transition state while the large value of βnuc1 is ascribed to the proton transfer in the early transition state of the rate-determining step.However, these low and high values of βnuc2 and βnuc1, respectively, are also compatible with the occurence of respective early and late transition states in the rate-determining step involving concerted intramolecular general base-catalysed nucleophilic attack at the carbonyl carbon of PS-.Significantly large positive deviations from Broensted plots have been observed for the reactivities of α-nucleophiles toward PS-.Monoprotonated ethane-1,2-diamine is ca. 20-fold more reactive than would be expected from its basicity, and this is attributed to the occurence of the intramolecular general acid catalysis.The reactions of PS- with hydroxylamine and N-methylhydroxylamine involve ca. >/=70 percent aminolysis and -.
- Khan, Mohammad Niyaz
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p. 199 - 208
(2007/10/02)
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- Effects of Anionic Micelles on Intramolecular General Base-catalysed Aminolysis of Phenyl and Methyl Salicylates
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The effect of micelles of sodium dodecyl sulphate (SDS) on aminolysis of ionized phenyl salicylate (PS-) and methyl salicylate (MS-) have been studied at 35 deg C.An increase in the total concentration of SDS (T) from 0.0 to 0.2 mol dm-3 results in a decrease in the observed nucleophilic second-order rate constants (kn) by a factor of ca. 3 for the reactions of PS- with propylamine and 1-aminopropan-2-ol.At high T, plots of observed pseudo-first-order rate constants (kobs versus total propylamine concentration (T) appear to exhibit smaller slopes at T -3 compared with those at T > 0.01 mol dm-3, while for 1-aminopropan-2-ol such deviations from linearity at T -3 could not be detected.These observations are attributed to the higher hydrophilicity of 1-aminopropan-2-ol compared with that of propylamine.The values of kn for hydrazinolysis of MS- are decreased ca. 1.7-fold and those for hydroxylaminolysis MS- are increased ca. 2-fold with an increase in T from 0.0 to 0.2 mol dm-3.The values of kn for methylaminolysis of MS- are independent of T within the limits 0.0-0.2 mol dm-3.Dimethylamine did not show any detectable nucleophilic reactivity toward MS- in the presence of 0.03 mol dm-3 SDS.This shows that the presence of SDS perhaps does not change the nucleophilic reaction mechanism of aminolysis of salicylate esters.The observed results of aminolysis of PS- and MS- are rationalized in the light of the proposal of a porous cluster micellar structure.
- Khan, Mohammad Niyaz,Dahiru, Mohammad,Naaliya, Janaidu
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p. 623 - 628
(2007/10/02)
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- 14N Quadrupole Double Resonance in Some Substituted Hydroxamic Acids
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14N quadrupole coupling constants and asymmetry parameters have been measured in a number of hydroxamic acids by double-resonance field-cycling techniques based on either irradiation in zero magnetic field or cross relaxation.The compounds all display high asymmetry parameters.Those in which this quantity is greater than 0.9 show remarkable line shapes for the two lower 14N frequencies (νy, νz) in their irradiation spectra.They are explained in terms of a thermal-mixing mechanism, which generates polarization of the 1H dipolar levels when these nearly degenerate frequencies are strongly irradiated in zero field, and then subsequently modified by level crossing when the sample is returned to high field to measure the remaining 1H signal.Ab initio SCF-MO calculations of the 14N quadrupole tensor in a group of molecules at the orientation found in crystals of acetohydroxamic acid hemihydrate and oxalodihydroxamic acid are in reasonable agreement with experiment and predict that in all the hydroxamic acids studied the maximum principal component is negative and closely parallel to the direction of the 2p? orbital.
- Ruiqin, Wang,Xiaolan, Yu,Zhenye, Feng,Haq, Mian M. I.,Khurshid, Muhammed M. P.,et al.
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p. 114 - 120
(2007/10/02)
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- SALICYLHYDROXAMIC ACID AND ITS IRON(III) COMPLEXES
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The dissociation constants of salicylhydroxamic acid (H2L), pKa1=6.73 and pKa2=9.15 (20 deg C, I=1.0 (NaClO4)), and the stability constant of the FeHL(2+) complex, log β=9.09, were determined by the potentiometric and spectrophotometric methods.The low-soluble Fe(OH)(HL)2*3 H2O complex was also isolated.The reagent can be conveniently used as an indicator for the chelatometric determination of iron.
- Springer, Vladimir,Hornackova, Magdalena,Karlicek, Rolf,Kopecka, Bozena
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p. 602 - 608
(2007/10/02)
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- Hydroxamic acid and pharmaceutical preparations containing the same
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Hydroxamic acids, pharmaceutical preparations containing the same, new ω(2''-naphthoxy)-alkylhydroxamic acids as well as a process for their production are disclosed. The new compounds display antiasthmatic and further pharmacologically valuable characteristics. They are prepared by reacting the corresponding carboxylic acid ester or amide with hydroxylamine or its salt under the described conditions into compounds of Formula I,R--CO--NH--OH.The compounds of Formula I are useful in human and veterinary medicine as medicaments the active principal of which is the inhibition of lipoxygenase, thus as antiasthmatic, antianaphylactic, antiphlogistic, antirheumatic and antithrombotic preparations.
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- Synthesis and Biological Evaluation of 1-(1,2-Benzisothiazol-3-yl)- and (1,2-Benzisoxazol-3-yl)piperazine Derivatives as Potential Antipsychotic Agents
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Members of the series of title compounds were tested for potential antipsychotic activity in relevant receptor binding assays and behavioral screens.Structure-activity relationships within the series are discussed.Compound 24 (BMY 13859-1), a (1,2-benzisothiazol-3-yl)piperazine derivative, was selected for further study because of its potent and selective profile in primary CNS tests.It was active in the Sidman avoidance paradigm and blocked amphetamine-induced stereotyped behavior in dogs for up to 7 h.The compound's lack of typical neuroleptic-like effects in therat catalepsy test and its failure to produce dopamine receptor supersensitivity following chronic administration indicate that it should not cause the movement disorders commonly associated with antipsychotic therapy.Although 24 has potent affinity for dopaminergic binding sites, its even greater affinity for serotonin receptors suggests that a serotonergic component may be relevant to its atypical profile.Compound 24 is currently undergoing clinical evaluation in schizophrenic patients.
- Yevich, Joseph P.,New, James S.,Smith, David W.,Lobeck, Walter G.,Catt, John D.,et al.
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p. 359 - 369
(2007/10/02)
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- Synthesis of hydroxy- and amino-substituted benzohydroxamic acids: Inhibition of ribonucleotide reductase and antitumor activity
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Benzohydroxamic acids inhibit mammalian ribonucleotide reductase and exhibit antineoplastic activity in L1210 leukemic mice. Five new hydroxy- and amino-substituted benzohydroxamic acids (3,4- and 3,5-OH,3,4-NH2, 2,3,4-, and 3,4,5-OH) were prepared and tested along with 12 previously reported benzohydroxamic acids (BHA) for enzyme inhibition and antitumor activity. The most potent enzyme inhibitor in this series was 2,3,4-OH-BHA (ID50=3.5 μM), which is 140 times more potent than hydroxyurea, but its toxicity limited the antitumor activity to a 30% increase in life span of L1210 bearing mice at 125 (mg/kg) day ip for 8 days. The most effective antitumor agent in this series was 3,4-OH-BHA which prolonged the life span of L1210 bearing mice 103% at 600 (mg/kg)/day ip for 8 days.
- van't Riet,Wampler,Elford
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p. 589 - 592
(2007/10/05)
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