- Synthesis of TiO2-Ag3PO4photocatalyst material with high adsorption capacity and photocatalytic activity: application in the removal of dyes and pesticides
-
The photocatalytic activity of TiO2can be enhanced by coupling it with other semiconductors and the semiconductor composites may find useful application in water treatment technologies. TiO2-Ag3PO4composites wer
- Agyei-Tuffour, Benjamin,Efavi, Johnson K.,Manu, Gloria,Nyankson, Emmanuel
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p. 17032 - 17045
(2021/05/25)
-
- Synthesis of 4,4′-Oxydibenzoic Acid Amides and Sulfonamides Containing 2-Arylaminopyrimidine Moieties
-
Abstract: New 4,4′-oxydibenzamides and sulfamoyl derivatives of 4,4′-oxydibenzoic acid containing pharmacophoric 2-arylaminopyrimidine fragments in the amide moiety have been synthesized. Acylation of amines of the pyrimidine series with 2-chlorosulfonyl-substituted 4,4′-oxydibenzoic acid gave the corresponding sulfonamides. Arylaminopyrimidine derivatives of 4,4′-oxydibenzamide were obtained in 75–87% yield by acylation of 3-{[4-(pyridin-3-yl)pyrimidin-2-yl]amino}anilines with 4,4′-oxydibenzoyl chloride. The reactivity of 4,4′-oxydibenzoyl chloride toward amines is discussed.
- Ignatovich, Zh. V.,Ermolinskaya,Petushok,Katok, Ya. M.,Koroleva
-
p. 2092 - 2097
(2021/02/09)
-
- The performance and degradation mechanism of sulfamethazine from wastewater using IFAS-MBR
-
Sulfamethazine (SMZ) is an important sulfonamide antibiotic. Although the concentration in the environment is small, it is harmful. The drug residues can be transferred, transformed or accumulated, affecting the growth of animals and plants. In this study, the integrated fixed-film activated sludge membrane bioreactor (IFAS-MBR) were constructed to investigate the performance and degradation mechanism of SMZ. The addition of SMZ had a significant impact on the removal of the chemical oxygen demand (COD) and ammonia nitrogen (NH4 +-N). The optimal operating conditions were hydraulic retention time (HRT) at 10 h and solid retention time (SRT) at 80 d, respectively. On this basis, the effects of different SMZ concentrations on nutrient removal, degradation, and sludge characteristics were compared. The removal efficiency of SMZ increased with the increase of SMZ concentration. The maximum removal rate was as high as 87%. The SMZ dosage also had an obvious effect on sludge characteristics. As the SMZ concentration increased, the extracellular polymer substances (EPS) concentration and the membrane resistance both decreased, which were beneficial for the reduction of membrane fouling. Finally, seven kinds of SMZ biodegradation intermediates were identified, and the possible degradation pathways were speculated. The microbial community results showed that the microbial diversity and richness in the reactor decreased after adding SMZ to the influent. The relative abundance of Bacteroidetes, Actinobacteria, Saccharibacteria and Nitrospirae increased at the phylum level. Sphingobacteria and Betaproteobacteria became dominant species at the class level. The relative abundance of norank-p-Saccharibacteria and Nitrospirae increased significantly, and norank-p-Saccharibacteria may be the dominant bacteria for SMZ degradation.
- Hou, Huanhuan,Duan, Liang,Zhou, Beihai,Tian, Yuan,Wei, Jian,Qian, Feng
-
supporting information
p. 543 - 546
(2019/09/07)
-
- Ultrasound-assisted rapid synthesis of 2-aminopyrimidine and barbituric acid derivatives
-
Novel, inexpensive, and relatively expeditious procedure to achieve the synthesis of different 2-aminopyrimidine and barbituric acid derivatives is presented here, starting from readily available compounds such as guanidine hydrochloride, urea, 1,3-dialkylurea, or thiourea. Under ultrasonic irradiation, base-driven (Na2CO3, NaOH, or NaOC2H5) heterocyclization reactions of the aforementioned substrates with diethyl malonate, diethyl-2-alkyl malonate, pentane-2,4-dione, or ethyl-3-oxobutanoate yielded corresponding products. Significant advantages of this sonochemical synthetic protocol with regard to the conventional thermal methods include easy reaction setup and work-up steps, reasonably mild conditions, shorter reaction times (～30 min) and comparably high product yields. The characterization of the synthesized compounds was based on melting points, FT-IR, GC-MS, 1H-NMR techniques, and the obtained data were also checked from the previously published studies.
- Bayramo?lu, Duygu,Kurtay, Gülbin,Güllü, Mustafa
-
p. 649 - 658
(2020/02/11)
-
- Imidazo[4,5-c]pyridine derivative and application thereof
-
The invention relates to a novel imidazo[4,5-c]pyridine derivative represented by a general formula I, and pharmaceutically acceptable salts, solvates or prodrugs of the novel imidazo[4,5-c]pyridine derivative, wherein the substituent R and R' are defined as in the specification. The invention also relates to an effect of the compound represented by the general formula I in inhibiting an NS5B RNA-dependent RNA polymerase (NS5B polymerase for short) which is necessary in a replication process of hepatitis c virus, also relates to an application of the compound, and pharmaceutically acceptable salts, hydrates or prodrugs of the compound in preparation of medicines for treating viral diseases, and especially relates to an application in preparation of medicines for treating and/or preventinghepatitis c.
- -
-
Paragraph 0135; 0138; 0139; 0140
(2019/10/01)
-
- Sulfonamide hapten, sulfonamide artificial antigen and their preparation methods and application
-
The invention relates to a sulfonamide hapten, a sulfonamide artificial antigen and their preparation methods and application. The sulfonamide hapten has a structure shown as formula (1) which is shown in the description, wherein n is an integer equal to 0, or greater than and equal to 1. The sulfonamide artificial antigen is made by coupling the hapten of the formula (1) and a carrier protein. Byimmunizing animals with the sulfonamide artificial antigen, specific antibodies with high efficacy and high sensitivity can be attained. The sulfonamide hapten and antibodies prepared with the same help provide a new means to establish a method to detect sulfonamides under high speed, good simplicity, low cost, good sensitivity and good specificity.
- -
-
Paragraph 0071; 0073
(2019/06/30)
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- Photolysis of sulfamethazine using UV irradiation in an aqueous medium
-
Although many studies have been focused on the photochemistry of antibiotics, the roles of reactive species in photolysis and the effects of dissolved substances on antibiotic photochemical behavior have been poorly examined. The photolytic behaviors of s
- Yi, Zhigang,Wang, Juan,Tang, Qiong,Jiang, Tao
-
p. 1427 - 1435
(2018/02/15)
-
- Design, synthesis, and structure-activity relationships of novel imidazo[4,5-c]pyridine derivatives as potent non-nucleoside inhibitors of hepatitis C virus NS5B
-
The hepatitis C virus (HCV) NS5B polymerase is an attractive target for the development of novel and selective inhibitors of HCV replication. In this paper, the design, synthesis, and preliminary SAR studies of novel inhibitors of HCV NS5B polymerase based on the structure of tegobuvir have been described. The efforts to optimize the antiviral potency and reduce the treatment side effects with respect to genotype 1b resulted in the discovery of compound 3, which exhibited an EC50 of 1.163 nM and a CC50 >200 nM in a cell-based HCV replicon system assay. Additionally, testing for inhibition of the hERG channel showed a marked improvement over tegobuvir and the pharmacokinetic properties of compound 3 indicated that it was worthy of further investigation as a non-nucleoside inhibitor of HCV NS5B polymerase.
- Liu, Moyi,Xu, Qiaoling,Guo, Su,Zuo, Ruixi,Hong, Yue,Luo, Yong,Li, Yingxiu,Gong, Ping,Liu, Yajing
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p. 2621 - 2631
(2018/04/30)
-
- Pyrimidine-substituted cinnamyl thiourea compound and application thereof
-
The invention discloses a pyrimidine-substituted cinnamyl thiourea compound. The pyrimidine-substituted cinnamyl thiourea compound is shown as a formula I. The compound shown in the formula I is takenas a plant growth regulator. As proved by a wheat seed soaking experiment, the compound shown in the formula I can remarkably increase the wheat germinating rate, and remarkably promote rooting; as proved by an expanding test of cucumber cotyledon, the compound shown in the formula I remarkably promotes cell division, and can effectively regulate and control plant growth. The formula I is shown in the description.
- -
-
Paragraph 0008; 0021; 0022
(2018/03/26)
-
- Proton Sensitive Functional Organic Fluorescent Dyes Based on Coumarin-imidazo[1,2-a]pyrimidine; Syntheses, Photophysical Properties, and Investigation of Protonation Ability
-
A novel series of 2-coumarin-3-yl-imidazo[1,2-a]pyrimidines have been synthesized with functionalized coumarin and pyrimidine units of the different architecture to give various fluorescent compounds. A new additional series bearing unsubstituted coumarin and 7-dialkylaminocoumarin as fluorophore were obtained by palladium-catalyzed cross-coupling reactions, through coupling of 6-bromo-2-coumarin-3-yl-imidazopyrimidine derivatives with various arylboronic acids. In the all reaction step, microwave irradiation (MWI) method was used and compared with the conventional method (CM). Photophysical properties of synthesized compounds were studied by a combination of UV/Vis and fluorescence spectroscopy in various solvents having different polarities. The protonation abilities of all compounds were investigated by titration with trifluoroacetic acid (TFA) in dichloromethane. In both series, the compounds bearing 7-dialkylaminocoumarin are fluorescently active even in daylight and showed maximum absorption wavelengths (λabs–max) in the visible region in all solvents used. In addition, they showed drastic color and emission change in acidic environment. Moreover, for the investigation of protonation ability of three selected compounds bearing 7-dialkylaminocoumarin have been studied using a buffer solution with various pH and determinated their pKa values. The compound bearing morpholine has the potential to use as colorimetric and luminescence pH sensor. The thermal properties of all the synthesized compounds were also evaluated with TGA to test their usability as optic dyes.
- Ayd?ner, Burcu,Sefero?lu, Zeynel
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p. 5921 - 5934
(2018/11/23)
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- Photodegradation of sulfamethazine, sulfamethoxypiridazine, amitriptyline, and clomipramine drugs in aqueous media
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The photochemical transformation of two antibacterial sulfonamides, namely sulfamethazine (SMT) and sulfamethoxypyridazine (SMP), and two tricyclic antidepressants, namely amitriptyline (AMT) and clomipramine (CMP) were investigated. Experiments conducted in river water under artificial sunlight irradiation show an acceleration of the degradation for SMT, SMP, and CMP of a factor 1.6–7.7 by comparison to purified water. This acceleration is, at least partially, due to photosensitized reactions which can occur in river water. The photodegradation of CMP was particularly fast. In addition, no degradation was observed for AMT in purified water while photosensitized reaction occurs. Under ultra-violet (254?nm) irradiation in purified water, the four drugs were degraded. Calculated quantum yields of photodegradation were of 4.3?×?10?3, 5.1?×?10?3, 7.6?×?10?3, and 65.0?×?10?3 respectively for SMT, SMP, AMT, and CMP. UV coupled with hydrogen peroxide (UV/H2O2) was used as an advanced oxidation process for water depollution. The calculated second order rate constants of reaction with hydroxyl radicals were of 5.0?×?109, 5.0?×?109, 8.0?×?109 and 9.5?×?109?L?mol?1?s?1 for SMT, SMP, AMT and CMP, respectively. Finally, the structures of photoproducts were proposed according to LC–MS/MS analyses. The elimination of SO2 was the main photochemical process for SMT and SMP. In the case of AMT and CMP, hydration and hydroxylation, respectively, were observed.
- Nassar, Rania,Trivella, Aurélien,Mokh, Samia,Al-Iskandarani, Mohamad,Budzinski, Hélène,Mazellier, Patrick
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p. 176 - 182
(2017/01/13)
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- Photolysis and photocatalytic decomposition of sulfamethazine antibiotics in an aqueous solution with TiO2
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Photo-decomposition of sulfamethazine (SMT) involves photolytic and photo-catalytic reactions, which occur simultaneously. The relative contributions of these two reactions to the overall SMT photo-decompositions by TiO2 and the intermediates of SMT photo-decompositions were systematically examined with the effects of TiO2 loading, and the pH and the initial SMT concentrations in the solutions. The apparent rate constants of SMT photo-decomposition reactions, which were well described by the pseudo-first-order kinetic model, ranged from 0.24 to 1.61 h-1. The overall photo-decomposition efficiencies of 0.072 mM SMT were the highest at pH 5.5 with 0.5 g L-1 TiO2 due to the adsorption-induced photocatalytic decomposition of SMT on TiO2. However, the SMT photolysis occurred more rapidly at pH 10. Two reactive species of holes and hydroxyl radicals concurrently participated in the photocatalytic decomposition of SMT, and the latter dominated the oxidative reactions of SMT on TiO2. Eight intermediates of SMT photo-decomposition were determined using LC-MS. Their time-dependent distributions indicated that the photo-decomposition of SMT was triggered by hydroxylation on aniline and dimethylpyrimidinyl moieties, followed by the cleavage of the S-N bond of SMT. Our results illustrated that the intermediates with dimethylpyrimidinyl groups possess strong resistance to photo-decomposition and played a determinant role in the photo-decomposition of SMT.
- Tzeng, Tai-Wei,Wang, Shan-Li,Chen, Chiing-Chang,Tan, Chen-Chung,Liu, Yu-Ting,Chen, Tsan-Yao,Tzou, Yu-Min,Chen,Hung
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p. 69301 - 69310
(2016/08/05)
-
- Synthesis, crystal structure and herbicidal activity of a series of [1,2,4]triazolo[1,5-a]pyrimidine-2-sulfonamide compounds
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With the aim of obtaining efficient, safe and environmentally friendly green herbicide, a series of [1,2,4]triazolo[1,5-a]pyrimidine-2-sulfonamide compounds (8a-8f) were synthesized by reacting 2-amino-5,7-(bis-substituted)- 1,2,4-triazolo[1,5-a]pyrimidine (4a and 4b) with 2-substituted-6-trifluoromethyl-benzenesulfonyl chloride (7a-7c). And their structures were characterized by H-NMR, C-NMR, HRMS, FTIR, single-crystal X-ray diffraction, elemental analysis. Moreover, their herbicidal activities against six species of weeds were evaluated. Three target compounds such as 8a, 8c and 8e, exhibited significant postemergence herbicidal activity against some common dicotyledons and monocotyledons under different concentrations. The structure and activity relationship is discussed based on the herbicidal performances of the compounds with different substituents. The investigation results indicated that the above structures could serve as lead compounds for the development of new herbicides.
- Ma, Yi-Chao,Yu, Ying-Hui,Hou, Guang-Feng,Huang, Ji-Han,Gao, Jin-Sheng
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p. 829 - 843
(2016/07/06)
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- 2-Amino-1,3,5-triazine chemistry: hydrogen-bond networks, Takemoto thiourea catalyst analogs, and olfactory mapping of a sweet-smelling triazine
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Abstract The chemistry of 4,6-dialkyl-2-amino-1,3,5-triazines with bulky alkyl substituents was investigated and their use as building blocks for preparing chiral thiourea organocatalysts explored. Reaction of ammonia with 4,6-di-tert-butyl-2-chloro-1,3,5-triazine gave 4,6-di-tert-butyl-1,3,5-triazin-2-amine which formed extended hydrogen-bond networks in the solid state according to X-ray crystallography. Selected heterocyclic amines were converted to isothiocyanates, and the latter reacted with (S,S)-2-(dimethylamino)cyclohexylamine to give enantiopure 1-hetaryl-3-[2-(dimethylamino)cyclohexyl]thioureas, with hetaryl representing either 4,6-dimethyl-1,3-diazin-2-yl, 4,6-diisopropyl-1,3,5-triazin-2-yl, or 4,6-di-tert-butyl-1,3,5-triazin-2-yl groups. These compounds are structural analogs of Takemotos's chiral thiourea organocatalysts (1-[3,5-bis(trifluoromethyl)phenyl]-3-[(1S,2S)-2-(dimethylamino)cyclohexyl]thiourea) with an aza-aryl instead of the 3,5-bis(trifluoromethyl)phenyl group. They feature a strong intramolecular N-H to N-1 hydrogen bond, as shown by X-ray crystallography of 1-(4,6-di-tert-butyl-1,3,5-triazin-2-yl)-3-[2-(dimethylamino)cyclohexyl]thiourea in the solid state and by 1H NMR spectroscopy of all derivatives in CDCl3 solution, which prevents them from acting as bifunctional organocatalyst. In the reaction of 4,6-di-tert-butyl-2-chloro-1,3,5-triazine with ammonia, 4,6-di-tert-butyl-2-ethoxy-1,3,5-triazine was identified as side-product displaying a mildly sweet, floral odor that is unusual for a 1,3,5-triazine. Analogs (>35) of 4,6-di-tert-butyl-2-ethoxy-1,3,5-triazine were prepared to define the important structural factors of the olfactophore.
- Hintermann, Lukas,P?thig, Alexander,Xiao, Li
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p. 1529 - 1539
(2015/08/18)
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- Graphitic carbon nitride for photocatalytic degradation of sulfamethazine in aqueous solution under simulated sunlight irradiation
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Graphitic carbon nitride (g-CN) is active for sulfamethazine (SMT) degradation under simulated sunlight irradiation, with 70% SMT conversion within 90 min and a half-life of SMT 14 times shorter than that in the absence of catalyst, and can be recycled for at least five times with no loss of activity, making it a potential material in practice for SMT removal.
- Xiao, Huahua,Zhu, Junjiang,Thomas, Arne
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p. 105731 - 105734
(2015/12/26)
-
- Factors affecting sonolytic degradation of sulfamethazine in water
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In this study, the major factors affecting sonolytic degradation of sulfamethazine (SMT), a typical pharmaceutically active compound, in water were evaluated. The factors tested included two operational parameters (i.e. initial SMT concentration and ultrasonic power), three dissolved gases (i.e. Ar, O 2 and N2), five most frequently found anions in water (NO3-,Cl-,SO42-,HCO3-andBr-), ferrous ion (Fe 2+), and four alcohols (methanol, ethanol, isopropyl alcohol, tert-butyl alcohol). Typically, the degradation rate was increased with the increasing initial SMT concentration and power. The degradation rate was accelerated in the presence of argon or oxygen, but inhibited by nitrogen. Effects of anions on the ultrasonic treatment were species-dependent. The SMT degradation rate was slightly inhibited by NO3-,Cl-,and,SO42- but significantly improved by HCO3-andBr-. The negative effects of alcohols acted as hydroxyl radicals scavengers with the following order: tert-butyl alcohol > isopropyl alcohol > ethanol > methanol. The synergetic effect of ferrous ion was mainly due to production of additional hydroxyl radicals (·OH) through Fenton chemistry. LC/MS/MS analysis indicated that the degradation of SMT by ultrasonic irradiation is mainly ascribed to ·OH oxidation. Of interest, although the SMT could be rapidly degraded by ultrasonic irradiation, the degradation products were rarely mineralized. For example, ～100% of 180 μM SMT was decomposed, but only 8.31% TOC was reduced, within 2 h at an irradiation frequency of 800 kHz and a power of 100 W. However, the products became much biodegradable (BOD 5/COD was increased from 0.04 to 0.45). Therefore, an aerobic biological treatment may be an appropriate post-treatment to further decompose the SMT degradation products.
- Gao, Yu-Qiong,Gao, Nai-Yun,Deng, Yang,Gu, Jin-Shan,Gu, Yu-Liang,Zhang, Dong
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p. 1401 - 1407
(2013/07/27)
-
- Effects of cytoprotective antioxidants on lymphocytes from representative mitochondrial neurodegenerative diseases
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Two new aza analogues of the neuroprotective agent idebenone have been synthesized and characterized. Their antioxidant activity, and ability to augment ATP levels have been evaluated in several different cell lines having suboptimal mitochondrial function. Both compounds were found to be good ROS scavengers, and to protect the cells from oxidative stress induced by glutathione depletion. The compounds were more effective than idebenone in neurodegenerative disease cells. These novel pyrimidinol derivatives were also shown to augment ATP levels in coenzyme Q10-deficient human lymphocytes. The more lipophilic side chains attached to the pyrimidinol redox core in these compounds resulted in less inhibition of the electron transport chain and improved antioxidant activity.
- Goldschmidt, Ruth,Arce, Pablo M.,Khdour, Omar M.,Collin, Valerie C.,Dey, Sriloy,Jaruvangsanti, Jennifer,Fash, David M.,Hecht, Sidney M.
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p. 969 - 978
(2013/03/14)
-
- Fluorous oxime palladacycle: A precatalyst for carbon-carbon coupling reactions in aqueous and organic medium
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To facilitate precatalyst recovery and reuse, we have developed a fluorous, oxime-based palladacycle 1 and demonstrated that it is a very efficient and versatile precatalyst for a wide range of carbon-carbon bond formation reactions (Suzuki-Miyaura, Sonogashira, Stille, Heck, Glaser-type, and Kumada) in either aqueous or organic medium under microwave irradiation. Palladacycle 1 could be recovered through F-SPE in various coupling reactions with recovery ranging from 84 to 95% for the first cycle. Inductively coupled plasma optical emission spectrometry (ICP-OES) analyses of the Pd content in the crude product from each class of transformation indicated extremely low levels of leaching and the palladacycle could be reused four to five times without significant loss of activity.
- Susanto, Woen,Chu, Chi-Yuan,Ang, Wei Jie,Chou, Tzyy-Chao,Lo, Lee-Chiang,Lam, Yulin
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experimental part
p. 2729 - 2742
(2012/05/21)
-
- A strategy for suppressing redox stress within mitochondria
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An aza analogue (1) of the experimental neuroprotective drug idebenone has been prepared and evaluated. The compound quenches lipid peroxidation more effectively than α-tocopherol and potently suppresses reactive oxygen species in cells under oxidative stress. It is thought to do so via a catalytic cycle in which both forms of oxidative stress are suppressed simultaneously. Consequently, the compound effectively protects cultured CEM leukemia cells and Friedreich's ataxia fibroblasts from oxidative stress more effectively than idebenone or idebenol.
- Arce, Pablo M.,Khdour, Omar M.,Goldschmidt, Ruth,Armstrong, Jeffrey S.,Hecht, Sidney M.
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supporting information; experimental part
p. 608 - 613
(2011/10/04)
-
- MULTIFUNCTIONAL RADICAL QUENCHERS AND THEIR USE
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The present disclosure provides biologically active compounds of formula (I): and pharmaceutically acceptable salts thereof, compositions comprising these compounds, and methods of using these compounds in a variety of applications, such as treatment or suppression of diseases associated with decreased mitochondrial function resulting in diminished ATP production and/or oxidative stress and/or lipid peroxidation.
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-
Page/Page column 35-36
(2011/09/19)
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- Design, microwave-assisted synthesis and HIV-RT inhibitory activity of 2-(2,6-dihalophenyl)-3-(4,6-dimethyl-5-(un)substituted-pyrimidin-2-yl)th iazolidin-4-ones
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A series of novel thiazolidin-4-ones bearing a hydrophobic substituent at 5-position on the 4,6-dimethyl-pyrimidine ring at N-3 (5c-i and 6c-i) were designed on the prediction of QSAR studies, synthesized in good yields of 60.1-85.3% by microwave-assisted one-pot protocol with the combination of using dicyclohexylcarbonimide (DCC) as the promotor, and evaluated as HIV-1 reverse transcriptases inhibitors. The results of in vitro HIV-1 RT kit assay showed that some of the new compounds, such as 5c, 6c, 5d, 6d, 5g, 5h and 6i, could effectively inhibit RT activity. Among them, compounds 5c and 6c where ethyl group existed at 5-position on N-3 pyrimidine ring were the best ones with the IC50 value of 0.26 μM and 0.23 μM, respectively. Structure-activity relationship analysis of these analogues suggested that the overall hydrophobicity and steric factor were important to the anti-HIV RT activity. The mechanism of the intramolecular cycloamidation promoted by DCC was also investigated with the key uncyclized intermediate 13.
- Chen, Hua,Bai, Jie,Jiao, Lingling,Guo, Zaihong,Yin, Qingmei,Li, Xiaoliu
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experimental part
p. 3980 - 3986
(2009/10/17)
-
- Syntheses and characterization of the pyrimido[1,2-a][1,3,5]triazinthione as a new ring system and antibacterial agent
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The pyrimido[4,5-e][1,2,4]triazine was prepared as a new ring system via annulation of the triazine ring onto the preformed pyrimidine derivative. Various S-benzoy lisothiourea derivatives were synthesized by condensation of benzoylthiocyanate with amines. All the synthesized compounds were tested as antimicrobial agents and compounds 11 and 12 showed significant activity toward to Klebsiella pneumoniae.
- Waly,Dobara, M. I. Abou
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experimental part
p. 1601 - 1607
(2010/08/03)
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- Microwave-expedited one-pot, two-component, solvent-free synthesis of functionalized pyrimidines
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The synthesis of a series of diversely substituted pyrimidines under solvent-free conditions in good yields is described. Under microwave irradiation, a variety of nucleophilic substrates containing the N?C?N unit with ?-dicarbonyl compounds, ethyl cyanoacetate, malononitrile, and chalcones was cyclized to give pyrimidines. A combinatorial type approach for a one-step synthesis has been developed where a ring-closing condensation is followed by spontaneous aromatization to afford 28 functionalized and aryl/alkyl substituted pyrimidines. CSIRO 2007.
- Goswami, Shyamaprosad,Jana, Subrata,Dey, Swapan,Kumar Adak, Avijit
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p. 120 - 123
(2008/02/11)
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- Preparation of pyrrole and pyrrolidine derivatives of pyrimidine. 1-(2-Pyrimidinyl)pyrrole - An inhibitor of X. Phaseoli and X. Malvacearum
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Pyrrole and pyrrolidine derivatives of pyrimidine were prepared in which the nitrogen atom of the pyrrole or pyrrolidine ring is bonded directly to the 2- or 4-carbon atom of the pyrimidine ring. Pyrrole derivatives were prepared by the dry distillation of an intimate mixture of an aminopyrimidine with mucic acid and by the reaction of a chloropyrimidine with potassium pyrrole. Pyrrolidine derivatives were prepared by the reaction of a chloropyrimidine with pyrrolidine and, in a single instance, by the catalytic hydrogenation of a pyrimidinylpyrrole. At a concentration of 200 mcg/mL, 1-(2-pyrimidinyl)pyrrole inhibited two plant pathogenic bacteria -Xanthomanus phaseoli (pathogenic on the bean plant) and Xanthomanus malvacearum (pathogenic on the cotton plant).
- Becker, Irwin
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p. 343 - 348
(2007/10/03)
-
- Synthesis of silylated β-enaminones and applications to the synthesis of silyl heterocycles
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Silyl β-enaminones have been synthesized by reductive cleavage of silylisoxazoles. These versatile synthons bearing the silyl group in different positions of the enamino ketonic system are of great interest in the construction of a variety of penta- and hexaheterocycles, which, in general, retain the silyl group attached at the ring or in a side chain.
- Calvo, Luis A.,González-Nogal, Ana M.,González-Ortega, Alfonso,Sa?udo
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p. 8981 - 8984
(2007/10/03)
-
- THE REACTION OF β-AMINOENONES WITH CYANAMIDE. A HIGH EFFICIENT SYNTHESIS OF 2-AMINOPIRIMIDINES.
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β-aminoenones react with cyanamide, molar ratio 1:2, to yield 2-aminopyrimidines in nearly quantitative yields.
- Alberola, Angel,Andres, Celia,Ortega, Alfonso Gonzalez,Pedrosa, Rafael,Vicente, Martina
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p. 1309 - 1314
(2007/10/02)
-
- Process for producing sulfonylureas
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There is described a novel process for producing sulfonylureas of formula I STR1 wherein R1 is hydrogen or alkyl, R2 is STR2 E is =N-- or =CH--, R3 is alkyl, alkoxy or halogen, R4 is alkyl, cycloalkyl, alkoxy, halogen, alkoxy-alkyl, halo-alkyl or halo-alkoxy, R5 is hydrogen or alkyl, T is a substituted phenyl group STR3 Y is hydrogen or halogen, X is hydrogen, halogen, alkyl, halo-alkyl, alkenyl, halo-alkenyl, alkynyl, alkoxy, halo-alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, halo-alkylthio, alkylsulfonyloxy, phenylsulfonyloxy, phenylsulfonyloxy mono- or polysubstituted by alkyl, or is di-alkylsulfamoyl, and A is a bridge member which has 3 or 4 atoms and which contains 1 or 2 hetero atoms, selected from the group consisting of oxygen, sulfur and nitrogen, the said process comprising reacting a silfonamide of the formula II in the presence of a base, with diphenyl carbonate to form a salt of a phenyl carbamate converting this salt into the free phenyl carbamate and reacting this further with an amine. Sulfonylureas are herbicidally effective compounds.
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-
- Heterocyclic Rearrangements: Rearrangement of N-(1,2,4-Oxadiazol-3-yl)-β-enamino Ketones into Pyrimidine N-Oxides
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The behaviour of N-(5-R-1,2,4-oxadiazol-3-yl)-β-enamino ketones towards rearrangement has been investigated.In the presence of anionic reagents in ethanol solution, they rearrange to pyrimidine N-oxides.The synthesis and hydrolytic ring opening of a oxadiazolopyrimidinium system is also reported.
- Vivona, Nicolo,Buscemi, Silvestre,Frenna, Vincenzo,Ruccia, Michele
-
-
- A C-13 nuclear magnetic resonance study of the pyrimidine synthesis by the reactions of 1,3-dicarbonyl compounds with amidines and ureas
-
The detailed mechanistic pathways are elucidated for the reactions of acetylacetone, methyl acetoacetate, and dimethyl malonate with a variety of amidines and ureas.In many cases the identification of a single intermediate allows the definition of the reaction path and identification of two steps.Intermediates characterized include ring-closed dihydroxytetrahydropyrimidines, dihydrohydroxypyrimidinones, open-chain enamides, and carbonyl addition compounds.
- Katritzky, Alan R.,Yousaf, Taher I.
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p. 2087 - 2093
(2007/10/02)
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- Reactions of β-Sulfenyl α,β-Unsaturated Ketones with Guanidine, Amidines and Diamines
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β-Sulfenyl α,β-unsaturated ketones 1a-c reacted with guanidine or amidines to give pyrimidine derivatives 3 in 14-76percent yields.Treatment of ketones 1 with diamines such as ethylenediamine and o-phenylenediamine afforded the seven-membered heterocycles, 2,3-dihydro-1,4-diazepine 5 and 2,3-benzo-1,4-diazepines 8a-c.
- Nishio, Takehiko,Tokunaga, Tatsuhiro,Omote, Yoshimori
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p. 405 - 407
(2007/10/02)
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- Herbicidal N-(heterocyclicaminocarbonyl)-ortho-haloalkylbenzenesulfonamides
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N-(heterocyclicaminocarbonyl)-ortho-haloalkylbenzenesulfonamides, such as 2-(dichloromethyl)-N-[(4-methoxy-6-methylprimidin-2-yl) aminocarbonyl]-benzenesulfonamide, are useful as preemergent or postemergent herbicides or as plant growth regulants.
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- Ring-expansion of Azidobenzenesulphonamides and Azidobenzamides
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4-Azidobenzenesulphonamides and 2- and 4-azidobenzamides undergo phototransformation to 2-alkoxy-3H-azepines in alcohols but the yields are low.Ring-expansion of 4-azidobenzenesulphonamide and 4-azidobenzenesulphonylguanidine in aqueous tetrahydrofuran to 3H-azepin-2(1H)-ones proceeds via a singlet nitrene pathway; thermolysis of 4-azidobenzenesulphonamide in aqueous dioxane gave only the triplet-derived product, sulphanilamide.Efficient de-azidation of 4-azidobenzesulphonamides and 4-azidobenzamides can be accomplished by heating the azides at 105 deg C in hydrazine hy drate.The crystallographic analysis of 5-sulphamoyl-3H-azepin-2(1H)-one shows the molecule to be non-planar with the azepine ring puckered in a boat form.The lactam configuration is confirmed with the carbonyl group having a bond length of 1.231 Angstroem.
- Brown, Thomas B.,Lowe, Philip R.,Schwalbe, Carl H.,Stevens, Malcolm F.G.
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p. 2485 - 2490
(2007/10/02)
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- Formation of Cycloadducts from Heterocyclic Formamidines and Phenyl Isocyanate
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Heterocyclic formamidines react with phenyl isocyanate at room temperature to give a cycloadduct which decomposes at elevated temperatures in two different ways; phenyl isocyanate reacts with the heterocyclic isocyanate formed in situ to form a new cycloadduct, a fused 1,3,5-triazine-2,4-dione derivative.
- Tisler, Miha,Stanovnik, Branko
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p. 313 - 314
(2007/10/02)
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