1072-67-9Relevant articles and documents
Insight into sulfamethoxazole degradation, mechanism, and pathways by AgBr-BaMoO4 composite photocatalyst
Ray, Schindra Kumar,Dhakal, Dipesh,Lee, Soo Wohn
, p. 686 - 695 (2018)
A composite photocatalyst, AgBr-BaMoO4 was fabricated by two step method; microwave hydrothermal and precipitation-deposition. The as prepared photocatalyst samples were characterized by various techniques. The facet coupling was seen between the (204) plane of BaMoO4 and (200)/(222) planes of AgBr on the basis of XRD/HRTEM analysis. The pharmaceutical pollutant, sulfamethoxazole was adopted to investigate the photocatalytic performances of samples under UV–vis irradiation. The AgBr-BaMoO4 composite degraded the aqueous sulfamethoxazole drug in UV–vis light about 64% within 75 min, which was attributed to efficient separation of photogenerated electron–hole pairs across the interface between Ag/AgBr and BaMoO4. The multi-electron induced oxygen reduced reaction (ORR) was observed. The radical trapping experiment indicates that OH? has major role for sulfamethoxazole degradation. The four successive photodegradation of sulfamethoxazole in UV–vis light indicates the stability of composite photocatalyst. Furthermore, the three different degradation pathways were designed on the basis of retention time and molecular masses of 18 degraded organic fragments that was confirmed by high-performance liquid chromatography photodiode array (HPLC-PDA) and high resolution-quadruple time of flight electrospray ionization mass spectroscopy (HR-QTOF ESI/MS) techniques. The total organic carbon (TOC) analysis suggested the mineralization of SMZ by composite photocatalyst. This study not only demonstrates the enhancement of photocatalytic performance of wide band gap semiconductor by making composite with narrow band gap semiconductor but also detail degradation pathways and mechanisms of sulfamethoxazole.
Effects of water environmental factors on the photocatalytic degradation of sulfamethoxazole by AgI/UiO-66 composite under visible light irradiation
Wang, Chao,Xue, Yao,Wang, Peifang,Ao, Yanhui
, p. 314 - 322 (2018)
It is necessary to find visible light responsive photocatalysts for rapid and simple degradation of organic pollutants in water environment. In this work, a visible light responsive composite photocatalyst AgI/UiO-66 was prepared by an in situ growth method. Sulfamethoxazole (SMZ) antibiotic was selected as the target contaminant to probe the photocatalytic performance of the as-prepared AgI/UiO-66 composite under visible light irradiation. The results showed that the photocatalytic performance of the AgI/UiO-66 composite enhanced significantly compared to pure AgI. The effects of typical environment factors (i.e. pH, inorganic salt ions and common anions) on the degradation of SMZ were evaluated extensively. Results showed that the investigated pH (5.2, 7.0, 9.5) had no apparent effect on the photocatalytic degradation of SMZ except pH 2.5, at which the degradation rate of SMZ decreased significantly. In addition, inorganic salt ions and Cl?, HCO3? and SO42? anions in water exhibited no apparent effect on the degradation of SMZ. The effect of water matrix on the degradation of SMZ was also investigated. In the river water, the removal efficiency of SMZ was reduced compared with the cleaner water matrix. The capture experiments of radicals confirmed that superoxide radicals ([rad]O2?) and hydroxyl radicals ([rad]OH) were the main active species for the photocatalytic degradation of SMZ in the present work. Finally, the tentative degradation pathways of SMZ were proposed based on the intermediates analysis.
Transformation of the antibacterial agent sulfamethoxazole in reactions with chlorine: Kinetics, mechanisms, and pathways
Dodd, Michael C.,Huang, Ching-Hua
, p. 5607 - 5615 (2004)
Sulfamethoxazole (SMX) - a member of the sulfonamide antibacterial class - has beenfrequently detected in municipal wastewater and surface water bodies in recent years. Kinetics, mechanisms, and products of SMX in reactions with free chlorine (HOCl/OCl-) were studied in detail to evaluate the effect of chlorination processes on the fate of sulfonamides in municipal wastewaters and affected drinking waters. Direct reactions of free available chlorine (FAC) with SMX were quite rapid. A half-life of 23 s was measured under pseudo-first-order conditions ([FAC]0 = 20 μM (1.4 mg/L) and [SMX]0 = 2 μM) at pH 7 and 25°C in buffered reagent water. In contrast, a half-life of 38 h was determined for reactions with combined chlorine (NH2Cl, NHCl2) under similar conditions. Free chlorine reaction rates were first-order in both substrate and oxidant, with specific second-order rate constants of 1.1 × 103 and 2.4 × 103 M -1 s-1 for SMX neutral and anionic species, respectively. Investigations with substructure model compounds and identification of reaction products verified that chlorine directly attacks the SMX aniline-nitrogen, resulting in (i) halogenation of the SMX aniline moiety to yield a ring-chlorinated product at sub-stoichiometric FAC concentrations (i.e., [FAC]0:[SMX]0 ≤ 1) or (ii) rupture of the SMX sulfonamide moiety in the presence of stoichiometric excess of FAC to yield 3-amino-5-methylisoxazole, SO42- (via SO2), and N-chloro-p-benzoquinoneimine. Reaction ii represents an unexpected aromatic amine chlorination mechanism that has not previously been evaluated in great detail. Experiments conducted in wastewater and drinking water matrixes appeared to validate measured reaction kinetics for SMX, indicating that SMX and likely other sulfonamide antibacterials should generally undergo substantial transformation during disinfection of such waters with free chlorine residuals.
0D/1D AgI/MoO3 Z-scheme heterojunction photocatalyst: Highly efficient visible-light-driven photocatalyst for sulfamethoxazole degradation
Xu, Jing,Chen, Juan,Ao, Yanhui,Wang, Peifang
supporting information, p. 3226 - 3230 (2021/05/29)
Low dimension nano photocatalysts show great potential in the field of treating contaminated water for their large surface area and size effect. In this study, a 0D/1D AgI/MoO3 Z-scheme photocatalyst with striking photocatalytic performance was constructed successfully. The one-dimensional MoO3 nanobelts were prepared by a simple hydrothermal method, and then it was modified by AgI nanoparticles in a handy deposition approach. When choosing sulfamethoxazole (SMZ) as the target contaminant, the rate constant value of the optimal 0D/1D AgI/MoO3 composite could hit up to 0.13 min?1, which is nearly 22.4 times and 32.5 times as that of pure MoO3 (0.0058 min?1) and AgI (0.0040 min?1), respectively. A series of detailed characterizations give evidences that the charge transfer in the composite followed Z scheme mechanism. Therefore, efficient separation/transfer and the remained high redox activity of photogenerated carriers played a vital role in the sharply enhanced photocatalytic properties. The possible degradation pathways of SMZ were proposed based on the intermediates detected by high-performance liquid chromatography-mass spectrometry (HPLC-MS). Meanwhile, the magnificent cyclic stability makes the material a promising material in the practical application.
Insights into the electrochemical degradation of sulfamethoxazole and its metabolite by Ti/SnO2-Sb/Er-PbO2 anode
Wang, Yanping,Zhou, Chengzhi,Wu, Jinhua,Niu, Junfeng
supporting information, p. 2673 - 2677 (2020/06/01)
Electrochemical degradation of sulfamethoxazole (SMX) and its metabolite acetyl-sulfamethoxazole (Ac-SMX) by Ti/SnO2-Sb/Er-PbO2 were investigated. Results indicated that the electrochemical degradation of SMX and Ac-SMX followed pseu
Preparation method 3 -amino -5 -alkyl isoxazole
-
Paragraph 0024-0025; 0028; 0029-0030; 0033, (2020/06/05)
The invention discloses a preparation method of 3-amino-5-alkyl isoxazole, realizes preparation through two steps and belongs to the technical field of organic chemistry. By starting from easily obtained aldehyde, after the addition with acetonitrile under the existence of metal alkali, an intermediate of hydroxy nitrile is obtained; then, the hydroxy nitrile reacts with hydroxylamine; ring closing reaction is performed under the existence of Lewis acid; after autoxidation, the 3-amino-5-alkyl isoxazole is obtained. The raw materials in the reaction process are very commons; chloroform or tetrachloromethane in a traditional method is avoided; potential industrial amplification prospects are realized.
A simple Fe3+/bisulfite system for rapid degradation of sulfamethoxazole
Fu, Yongsheng,Liu, Yiqing,Wang, Guangsheng,Wang, Hongbin,Wang, Shixiang
, p. 30162 - 30168 (2020/09/03)
Sulfate radical (SO4-) based oxidation technologies have been widely used in the remediation of antibiotic-containing wastewater. Activated persulfates are efficient reagents for achieving SO4-, but the storage and transportation of concentrated persulfates present associated safety issues. In this study, bisulfite (BS) was used as an alternative precursor for replacing persulfates, and a simple advanced oxidation system (Fe3+/BS) for generating SO4- and hydroxyl radical (HO) was formulated and evaluated for removing sulfamethoxazole (SMX) from contaminated water. The initial pH, dosages of Fe3+ and BS, as well as the water matrix were investigated to improve the SMX degradation. The results indicated that 1 μmol L-1 SMX was completely removed within 5 min at optimum initial pH of 4.0, Fe3+ dosage of 10 μmol L-1, BS dosage of 100 μmol L-1 and temperature of 25 °C. The presence of HCO3- and natural organic matter (NOM) showed obviously negative effects on SMX degradation, while Cu2+ could slightly promote the degradation of SMX if its concentration was in an appropriate range (～1 μmol L-1). Scavenger quenching experiments confirmed the presence of SO4- and HO, which resulted in efficient SMX degradation in the Fe3+/BS system. During the radical chain reactions, Fe2+ and Fe3+ could be converted into each other to form self-circulation in this system. The degradation pathway of SMX by Fe3+/BS was proposed including hydroxylation and bond cleavage.
Preparation method for 3-amino-5-methylisoxazole
-
Paragraph 0027; 0035; 0043, (2018/04/03)
The invention discloses a preparation method for 3-amino-5-methylisooxazole, belonging to the technical field of organic chemistry. The preparation method is completed through three steps: with an easily-available raw material namely ethyl acetate as a starting material, carrying out a reaction with acetonitrile in the presence of an alkali metal so as to form acetyl acetonitrile, then carrying out a reaction with p-toluenesulfonhydrazide so as to form hydrazone, and carrying out a ring closing reaction with hydroxylamine under an alkaline condition so as to obtain the 3-amino-5-methylisoxazole. According to the invention, raw materials in the reactions are common; chloroform or carbon tetrachloride in a traditional method are avoided; and analogous isomers of the 3-amino-5-methylisoxazoleare not detected in the reaction process.
Preparation and evaluation of N-sulfinyl dienophiles for asymmetric hetero-Diels-Alder reactions
Endeshaw, Molla Mellese,Hansen, Lars K.,Gautun, Odd R.
, p. 149 - 154 (2008/09/20)
(Chemical Equation Presented) A series of N-sulfinyl dienophiles 1c-i has been screened in asymmetric hetero-Diels-Alder reactions using chiral bis(oxazoline)copper(II) and -zinc(II) triflates. The survey pointed out N-sulfine 1c (R = P(=O)(OPh)2) as the most promising N-sulfine regarding yield and stereoselectivity (up to 97% ee). The relative configurations, and in one case the absolute configuration, of the HDA adducts were established by X-ray analysis.
Isoxazolyl enaminones
-
, (2008/06/13)
An oxazolyl enaminone is provided having the formula: STR1 wherein R1 is selected from the group consisting of a branched or unbranched alkyl groups containing from 1 to 4 carbon atoms and R2 is selected from the group consisting of a branched or unbranched alkyl group containing from 1 to 4 carbon atoms, a chloro group, a trifluoromethyl group and a trifluoromethoxy group. Also provided are pharmaceutically accepatable salts and isomers of the above, and pharmaceutical compositions containing the same.
