- Microwave (MW), ultrasound (US) and combined synergic MW-US strategies for rapid functionalization of pharmaceutical use phenols
-
Increasingly stringent regulations aimed at protection of the natural environment have stimulated the search for new synthetic methodologies in organic and medicinal chemistry having no or minimum harmful effect. An interesting approach is the use of alternative activation factors, microwaves (MW) or ultrasounds (US) and also their cross-combination, which has been tested in the fast and efficient creation of new structures. At present, an easy and green hybrid strategy (“Lego” chemistry) is generally recommended for the design of new substances from different chemistry building blocks. Often, selected biologically active components with specific chemical reactivities are integrated by a suitably designed homo- or heterodifunctional linker that modifies the functionality of the starting structure, allowing easy covalent linkage to another molecule. In this study, a fast introduction of heterodifunctional halogenoacidic linker to selected mono-, di- and triphenolic active substances, allowing their functionalization, was investigated. Nucleophilic substitution reaction was chosen to produce final ethers with the reactive carboxylic group from phenols. The functionalization was performed using various green factors initiating and supporting the chemical reactions (MW, US, MW-US). The benefits of the three green supporting methods and different conditions of reactions were analyzed and compared with the results of the reaction performed by conventional methods.
- Pawe?czyk, Anna,Sowa-Kasprzak, Katarzyna,Olender, Dorota,Zaprutko, Lucjusz
-
-
Read Online
- Synthesis, Structure, and Properties of the 2-[5-(Aryloxyacetyl)-Amino-1,3,4-Thiadiazol-2-Ylthio] Propionate Derivatives
-
A series of novel 2-[5-(aryloxyacetyl)-amino-1,3,4-thiadiazol-2-ylthio] propionate derivatives were synthesized in high yield, and their structures were characterized by IR, 1H NMR, 13C NMR, and elemental analysis, coupled with one selected single-crystal X-ray structure determination. The herbicidal activities of target compounds were assessed. The preliminary bioassay results showed that some compounds exhibited moderate to strong herbicidal symptoms in preemergence and postemergence tests. At 150 g/ha, S. tritici. show tolerance, while E. crus-galli L., E. Dahuricus, A. retroflexus, and C. glaucum L. were killed or severely injured. The activity of some compounds was comparable to the commercial herbicide 2,4-D. A suitable electron-withdrawing substituent at the 2-and/or 4-position of the phenyl ring was essential for high herbicidal activity. Moreover, the antifungal activities of the compounds have also been studied. The compounds were found to possess broad-spectrum antifungal activity.
- Hu, Bing,Zhai, Yue-Yuan,Zhang, Ling,Zhang, You-Ming,Wei, Tai-Bao
-
-
Read Online
- Triazole-amide isosteric pyridine-based supramolecular gelators in metal ion and biothiol sensing with excellent performance in adsorption of heavy metal ions and picric acid from water
-
Pyridine-based small molecular gelators 1-4, having a triazole-amide isosteric relationship, have been synthesized. Compounds 1-3 exhibit excellent gelation from DMSO-H2O (1?:?2, v/v), while compound 4 forms a gel in the presence of Ag+ ions in DMSO-H2O (1?:?2, v/v). The change from triazole to isosteric amide has a marked effect on the gelling abilities, minimum gelation concentrations (mgc), thermal stability, mechanical properties, metal ion-responsive character and adsorption properties of the structures, as established by various techniques. All the gels have been successfully applied in sophisticated sensing kits for the selective detection of Cu2+ and Ag+ ions and thiol-containing amino acids. The triazole-based gelators 1 and 3 adsorb heavy metal ions from water with greater efficiency than the isosteric amide-based gelators. The metallogel 4-Ag+ can be used in the efficient removal of picric acid (a nitro explosive) from water.
- Panja, Atanu,Ghosh, Kumaresh
-
-
Read Online
- A novel macrocyclic organotin carboxylate containing a penta-nuclear long ladder
-
A novel macrocyclic organotin carboxylate [(n-Bu2SnO) 5L] (complex 1) [H2L = (3-carboxymethoxy-phenoxy) acetic acid] was synthesized by the reaction of di-n-butyltin oxide with H2L and is characterized by elemental analyses i.e. IR 1H NMR and UV spectroscopies. X-ray crystallography diffraction analysis reveals that complex 1 is a centrosymmetric macrocycle and contains a penta-nuclear four-fold-ladder-like organo-oxotin cluster. All five Sn atoms are five-coordinated and the coordination environment can be considered as a trigonal bipyramidal. The luminescent property of complex 1 has also been investigated. Pilot studies have confirmed that complex 1 has shown good antitumor activity.
- Sougoule, Aboubacar Sidiki,Mei, Zemin,Xiao, Xiao,Balde, Cheick Abdoul,Samoura, Salematou,Dolo, Arouna,Zhu, Dongsheng
-
-
Read Online
- Synthesis and charge-transfer complexation studies on bis(aminomethyl) m-terphenyl based bis-oxycyclophanes with intra-annular amide functionality
-
Bis(aminomethyl) m-terphenyl based bis-oxy cyclophanes with amide group as intra-annular functionality were synthesized and characterized from spectral and analytical data. All the cyclophanes form 1:1 charge-transfer (CT) complex with TCNQ. ARKAT-USA, Inc.
- Rajakumar, Perumal,Padmanabhan, Ramar
-
p. 155 - 163
(2012/05/19)
-
- Visual chiral recognition of mandelic acid and α-amino acid derivatives by enantioselective gel formation and precipitation
-
Novel chiral receptors based on l-phenylalanine and l-valine have been synthesized and their chiral recognition properties toward mandelic acid and N-tosyl α-amino acids are studied. The phenylalanine-based receptor undergoes enantioselective gel formation with R-mandelic acid and N-tosyl-d-valine, whereas the valine-linked receptor in their presence results in the formation of precipitates.
- Tripathi, Anamica,Kumar, Anjul,Pandey, Pramod S.
-
supporting information
p. 5745 - 5748
(2012/11/06)
-
- Solvent-free synthesis of novel chiral unsymmetrical urea molecular tweezers under microwave irradiation
-
Seven novel chiral unsymmetrical urea molecular tweezers based on 1, 3-phenoxyacetic acid have been designed and synthesised using solid K 2CO3 as supporter in the solvent-free conditions under microwave irradiation. This method is simple, fast, efficient and eco-friendly. The structures of target compounds were characterised by IR, 1H NMR, MS spectra and elemental analyses and their molecular recognition properties were investigated by UV-Vis spectral titration. The preliminary results indicated that these molecular tweezers possess good selectivity for D/L amino acid methyl esters and some anions.
- Zhao, Zhigang,Xia, Zhenyang,Li, Xiaorui,Shi, Peiyu
-
scheme or table
p. 47 - 50
(2011/05/04)
-
- Synthesis and characterisation of novel 1,3-bis{(6-aryl-1,2,4-triazolo [3,4-b][1,3,4]thiadiazol-3-yl)-methoxy}benzenes under microwave irradiation
-
Eleven novel 1,3-bis{(6-aryl-1,2,4-triazolo[3,4-b][1,3,4]thiadiazol-3-yl)- methoxy}benzenes have been synthesised in high yields by the condensation of 5,5'-[1,3-phenylene-bis(oxymethylene)]bis(4-amino-3-mercapto-1,2,4-triazole) with substituted benzoic acids in the presence of phosphorus oxychloride under microwave irradiation. Compared with the conventional heating method, this method is facile, rapid and efficient. The structures of all new compounds were characterised by 1H NMR, IR, MS and elemental analysis.
- Mei, Qinggang,Yang, Jie,Peng, Yongle,Zhao, Zhigang
-
scheme or table
p. 386 - 389
(2011/10/08)
-
- Synthesis of 1,1,1-trichloro-2,2-bis-(carboxymethoxyaryl)ethanes as potential antimicrobial and insecticidal agents
-
Some new 1,1,1-trichloro-2,2-bis-(carboxymethoxyaryl)-ethanes 2a-t have been synthesised by the treating aryloxyacetic acid (two moles) with chloral hydrate (1 mole) in the presence of catalytic amount of conc. sulphuric acid. The aryloxyacetic acid are prepared by the reaction of substituted phenols with chloroacetic acid in the presence of aq. sodium hydroxide. The antimicrobial activity of these compounds have been assayed against various Gram+ve, Gram-ve bacteria and fungi. The constitution of the products have been elucidated by IR, 1H NMR and mass spectral data and elemental analyses.
- Purohit,Shah
-
p. 618 - 622
(2007/10/03)
-
- Solvent-free synthesis of substituted phenoxyacetic acids under microwave irradiation
-
A comparison of microwave-activated vs. classical organic synthesis is presented for a variety of growth-regulator compounds with a phenoxyacetic acid structure. Microwave-assisted nucleophilic substitutions are safely and conveniently carried out in an open vessel, without any solvent. Yields are very good, and reaction times are extremely short.
- Nagy, Gabriela,Filip, Sorin V.,Surducan, Emanoil,Surducan, Vasile
-
p. 3729 - 3736
(2007/10/03)
-
- Process for the preparation of aryloxyacetic acid
-
Process for the preparation of an aryloxyacetic acid by oxidation of aryloxyethanol of the formula: STR1 wherein m represents 1 or 2, n represents the numeral which results from the difference between 6 and m and R either individually or independently of one another represents hydrogen, alkyl, cycloalky, aryl, aralkyl, alkoxy, cycloalkoxy, aryloxy, halogen, alkylcarbonyl, arylcarbonyl, carboxyl or nitro, or represents a benzene ring fused to the phenyl ring, in an aqueous alkaline reaction medium at a temperature in the range of 0° C. to the boiling point of the reaction medium in the presence of a catalytic amount of a catalyst comprised of palladium, silver and optionally antimony, and carbon to form the corresponding alkali metal ester and contacting the alkali metal with a mineral acid.
- -
-
-
- THE PREPARATION AND PROPERTIES OF NEUTRAL DIAMIDE IONOPHORES FOR GROUP IIA METAL CATIONS-II
-
The elaboration of a series of neutral ligands featuring vicinal ether and N,N-dialkylacetamido groups is described.Several of these ligands were previously described.The ligands are moderate binders with Kapp=1E3-1E5 in methanol of the Group IIA cations for wich they are sensitive.Binding constants by Scatchard method are reported for number of ligands mainly with Ca, Sr, Mn and Ba.The ligands in methylene chloride solution extract these cations via their picrate salts from water.The electrochemical Kijpot (selectivity) values for some of the ligands when they are incorporated into liquid membrane electrodes and tested with various cations as determined by Simon et al. (ETH Zurich) are reported.Selectivity ratios of over 100:1 for Na vs Ca were found for several piperidenyl amides of 1,2-phenylenedioxydiacetic acid.Incorporation of N-methylamino instead of ether oxygen groups into the basic structure gives a stronger cation binder which is still selective for Group IIA vs Group IA cations but with binding capacity for transition metal cations also.Limitations of the Scatchard plots for these ligands and the non-correspondance of electrochemical selectivities with the ordering of binding of cations in single liquid phase are discussed.
- Borowitz, Irving J.,Readio, Josephine D.,Li, Ven-Shun
-
p. 1009 - 1016
(2007/10/02)
-