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1.
The condensation products of 5-amino-1,3-disubstituted-pyrazoles with aromatic aldehydes were identified as 2,4-dihydro-2,5-diphenyl-4-(phenylmethylene)-3H-pyrazol-5-imine derivatives Treatment of these products with mercaptoacetic acid gave new fluorine containing 1H-pyrazolo[3,4-e][1,4]thiazepin-7-ones. 相似文献
2.
Microwave-activated solvent-free Michael addition of 3-imino-1,4,2-dithiazoles to 4-arylidene-5(4H)-oxazolones furnished isolable adducts regio- and diastereoselectively, which underwent ring transformation to yield the target dithiazolopyrimidines. Alternatively, the similar conjugate addition of methanesulfinylmethylisothioureas to 4-arylidene-5(4H)-oxazolones diastereoselectively afforded Michael adducts, which underwent ring transformation followed by heterocyclization via deoxygenative demethylation with thionyl chloride to yield the same products dithiazolopyrimidines regio- and diastereoselectively. 相似文献
3.
Krishna C. Joshi Vijai N. Pathak Raj Pal Singh 《Monatshefte für Chemie / Chemical Monthly》1980,111(6):1343-1350
Several new 2-(fluoroaryl)-3-dialkylaminomethylindoles, 3-acetyl-2-(fluoroaryl)-indoles, 2-(fluoroaryl)-3-indolylglyoxamides and corresponding tryptamines have been prepared as possible psychopharmacological agents. 2-(Fluoroaryl)-indoles have been synthesized by theFischer indole synthesis. 2-(Fluoroaryl)-indoles on treatment with oxalyl chloride and subsequent reaction with amines, gave 2-(fluoroaryl)-3-indolylglyoxamides. Some of these indolylglyoxamides were reducted with lithium aluminium hydride, to the corresponding tryptamines. 2-(Fluoroaryl)-indoles when subjected toMannich reaction afforded 3-dialkylaminomethyl-2-(fluoroaryl)-indoles. All these new compounds have been characterized by IR spectral studies.Possible Psychopharmacological Agents, Part XII, Part XI, J. Indian. Chem. Soc.57, 423 (1980). 相似文献
4.
Patrick Koch Carl Djerassi Vijai Lakshmi Francis J. Schmitz 《Helvetica chimica acta》1983,66(8):2431-2436
Thirty-two sterols are identified in the sponge Hyrtios sp. In addition to fourteen monohydroxylated compounds, the sterol fraction contains eight functionalized sidechain sterols, three of them new: 3 β-hydroxy-24-norchol-5-en-23-al (19) , (22-trans)-3 β-hydroxycholest-5, 22-dien-24-one (20) and (22R, 23R, 24S) or (22S, 23S, 24S)- 22,23-epoxy-24-methylchoest-5-en-3 β-ol (24). The probable biological origin, rather than artifact production, of these undescribed components is discussed. 相似文献
5.
Treatment of 1H-4,5-dihydro-3-aryl-5-(2-hydroxyaryl)pyrazole with o-dibromoxylene under liquid-liquid phase transfer catalytic conditions using tetra-n-butylammonium hydrogen sulphate or [18]-crown-6 as PT catalyst, benzene/chloroform as organic phase and 50% aqueous potassium hydroxide as second phase, afforded novel 2,5,9,10-tetrahydro [7,8-g] benzo-8-arylpyrazolo[4,5-e] [1,5-b] benzoxazonines. 相似文献
6.
Pharmaceuticals, especially fluoroquinolone antibiotics, have received increasing global concern, due to their intensive use in the environment and potential harm to ecological system as well as human health. Degradation of antibiotics, such as oxidative degradation by metal oxides, often plays an important role in the elimination of antibiotics from the environment. The kinetics of oxidation of levofloxacin by water-soluble manganese dioxide has been studied in aqueous acidic medium at 25 °C temperature. The stoichiometry for the reaction indicates that the oxidation of 1 mol of levofloxacin requires 1 mol of manganese dioxide. The reaction is second order, that is first order with respect to manganese dioxide and levofloxacin. The rate of reaction increases with the increasing [H+] ion concentration. A probable reaction mechanism, in agreement with the observed kinetic results, has been proposed and discussed. The energy and enthalpy of activation have been calculated to be 30.54 and 28.07 kJ mol?1, respectively. 相似文献
7.
Vijai K. Rai Suhasini Mahata Smita R. Bhardiya Prashant Shukla Ankita Rai Manorama Singh 《Tetrahedron letters》2019,60(7):524-529
Reduced graphene oxide (rGO)–NaBH4 is reported as mild and efficient catalyst-system for chemo-/regioselective reduction of structurally different aliphatic, aromatic as well as α,β-unsaturated aldehydes and ketones in water. The rGO was prepared by reducing graphene oxide using Tulsi leaf extract as bio-reductant. Operational simplicity, ambient reaction condition, high yield of pure products (80–97%), no by-product formation, no use of column chromatography for purification are the salient features of the envisaged protocol. Furthermore, the recovered TRGO was recycled and reused for subsequent reductions up to five times without any loss in activity. 相似文献
8.
9.
A chiral ionic liquid-catalyzed, efficient and unprecedented version of the Biginelli reaction using new variants of its active methylene component, viz. 2-phenyl-1,3-oxazol-5-one/2-methyl-2-phenyl-1,3-oxathiolan-5-one, with aromatic aldehydes and urea/thiourea enantio- and diastereoselectively, yields 5-amino-/mercaptoperhydropyrimidines. This three-component domino cyclocondensation reaction is effected via ring transformation of an isolable intermediate in a one-pot procedure. 相似文献
10.
Spontaneous separation of chiral phases was observed in the monolayers of a racemate of gemini-type twin-tailed, twin-chiral amphiphiles, (2R,3R)-(+)-bis(decyloxy)succinic acid and (2S,3S)-(-)-bis(decyloxy)succinic acid. The pressure-area isotherms of the interfacial monolayers formed at the liquid-air interface, and the 2D lattice structures studied through surface probe measurements revealed that the racemate exhibits a homochiral discrimination of the enantiomers in two dimensions. An enantiomeric excess (e,e) of 20% was sufficient to break the chiral symmetry at the air-water interface for a homochiral interaction. Langmuir monolayers on ZnCl2 and CaCl2 subphases manifested chiral discrimination with Zn2+ evidencing homochiral interaction with a chelate-type complex, whereas Ca2+ resulted in a heterochiral interaction forming an ionic-type complex. For the chiral asymmetric units, oblique and rectangular unit cells of the racemic monolayer had exclusive requirements of homo- and heterochiral recognitions for Zn2+ and Ca2+ ions, respectively. Monolayers transferred from the condensed phase at 25 mN/m onto hydrophilic Si(100) and quartz substrates revealed the formation of bilayers through transfer-induced monolayer buckling. The emergence of homochiral discrimination was explained using the effective-pair-potential (EPP) approach. 相似文献