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11.
Subarna Jyoti Kalita Rajarshi Bayan Jutika Devi Sanfaori Brahma Hormi Mecadon Dibakar Chandra Deka 《Tetrahedron letters》2017,58(6):566-569
A new, simple and efficient synthesis of 4-alkyl-5-methyl-1H-pyrazol-3-ols in water by a two-pot four component reaction of ethyl acetoacetate, hydrazine hydrate, aldehyde and ketone in presence K2CO3 as the catalyst is described. Use of water as the reaction medium, operational simplicity, mild reaction conditions, application of a cost-effective, nontoxic and easily available catalyst with auto-tandem catalysis, wide substrate scope, easy workup and purification process make the protocol highly attractive. 相似文献
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Osmo E.O. Hormi Esko O. Pajunen Ann-Kristin C. Avail PÄIvi Pennanen Jan H. Näsman Mats Sundell 《合成通讯》2013,43(12):1865-1867
A cheap procedure for the preparation of tetraethyl methylene-diphosphonate is described. 相似文献
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Laloo BM Mecadon H Rohman MR Kharbangar I Kharkongor I Rajbangshi M Nongkhlaw R Myrboh B 《The Journal of organic chemistry》2012,77(1):707-712
An efficient regioselective protocol for the C-C bond formation by the unexpected α,α-diarylation of aromatic ketones with unactivated arenes in the presence of selenium dioxide and boron trifluoride etherate has been developed. The generality and functional tolerance of this protocol is demonstrated by the synthesis of a series of triarylethanones. 相似文献
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Two new ligands prepared under solvent free conditions and five aluminum complexes derived from 8-hydroxyquinoline have been synthesized and characterized. The majority of the new aluminum tris(8-hydroxyquinoline) derivatives have nitrogen functionalities at position-4 of the quinolate ligand. The photoluminescence emission wavelengths of the new Alq3 derivatives are shifted according to the electronic properties of the substituents at position-4. Results from differential scanning calorimetry (DSC) investigations of the new Alq3 derivatives indicate that the complexes 9 and 10 are non crystalline and have higher transition glass temperatures than the parent Alq3. The EL measurements of OLED devices with complexes 7, 9, and 10 as emitters revealed that complexes 7, 9, and 10 are efficient emitters in organic light emitting diodes. 相似文献
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Cationic wood cellulose films with high strength and bacterial anti-adhesive properties 总被引:1,自引:0,他引:1
Juho Antti Sirviö Anna-Kaisa Anttila Anna Maria Pirttilä Henrikki Liimatainen Ilkka Kilpeläinen Jouko Niinimäki Osmo Hormi 《Cellulose (London, England)》2014,21(5):3573-3583
In this work, periodate oxidized birch wood pulp and microfibrillated cellulose (MFC) were cationized using Girard’s reagent T or aminoguanidine. Cationic celluloses were used to obtain films via solvent-casting method, and the effects of the cationization route and the cellulose fiber source on the properties of the films were studied. Thermal and optical properties of the films were measured using differential scanning calorimetry and UV–Vis spectrometry, and the morphology of the films was examined using an optical microscope and a field emission scanning electron microscope. Bacterial anti-adhesive properties of the films were also studied using a modified leaf print method and against Staphylococcus aureus and Escherichia coli. Both cationizing agents exhibited similar reactivity with periodate oxidized celluloses, however, MFC had significantly higher reactivity compared to birch pulp. The films with high tensile strength (39.1–45.3 MPa) and modulus (3.5–7.3 GPa) were obtained from cationized birch pulp, aminoguanidine modification producing a film with slightly better mechanical properties. Modulus of the films was significantly increased (up to 14.0 GPa) when MFC was used as a cellulose fiber source. Compared to the unmodified MFC films, the cationic MFC films were less porous and significantly more transparent; however, they had slightly lower tensile strength values. It was found that aminoguanidine modified celluloses had no culturable bacteria on its surface and also exhibited resistance to microbial degradation, whereas there were culturable bacteria on the surface of Girard’s reagent modified films and they were partially degraded by the bacteria. 相似文献
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The Schiff bases of salicylaldehyde and pyridoxal 5-phosphate with amino compounds were studied by1H NMR in CD3OD by using a glass electrode for the control of acidity. This study makes a new contribution for the elucidation of the structures of pyridoxylidene Schiff bases and gives additional data on the1H NMR of the compounds that have not been available from the related studies in aqueous solutions. 相似文献
18.
Md. Rumum RohmanHormi Mecadon Abu T. KhanBekington Myrboh 《Tetrahedron letters》2012,53(39):5261-5264
The γ-alumina catalyzed synthesis of a new series of β-functionalized 5-methyl-1H-pyrazol-3-ol derivatives by the multi-component reaction of an aldehyde, ethylcyano acetate, and in situ generated 3-methyl-1H-pyrazol-5(4H)-one obtained from hydrazine monohyrade and ethyl acetoacetate in aqueous medium is described. The present reaction forms an important variant of the Yonemitsu-type multi-component reaction. The salient features of this present environmentally benign method are: recyclability of the catalysts, mild reaction condition, excellent yields of product, and the use of aqueous medium in the reaction. 相似文献
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Walaa A. E. Omar Juha P. Heiskanen Osmo E. O. Hormi 《Journal of heterocyclic chemistry》2008,45(2):593-595
Six 8‐hydroxyquinolines with amino and thioalkyl functionalities at position 4 have been prepared. The synthesis starts with chlorination of the readily available 4‐hydroxy‐8‐tosyloxyquinoline to give 4‐chloro‐8‐tosyloxyquinoline in 94% yield. Treatment of the 4‐chloro‐8‐tosyloxyquinoline with sulphur and nitrogen nucleophiles produces the target 4‐amino and 4‐thioalkyl‐8‐hydroxyquinolines in more than 70% yield. In case of sulphur nucleophiles and pyrrolidine, the removal of the protecting tosyl group at position 8 occurs simultaneously with the substitution of chlorine at position 4. 相似文献