Summary The reaction of furil (1) with trialkyl phosphites2 yielded caged phosphorane derivatives of types3a-c. Dry hydrogen chloride gas converted3a-c into the respectivea-hydroxyvinyl-phosphates8a-c which are equally produced by reacting furil with the appropriate dialkyl phosphite7. The reaction of furil with ylide-phosphoranes10 proceeded according to the Wittig reaction mechanism to give the respective ethylenes11a-c. The new compounds have been characterized by their spectroscopic data (IR, PMR,31P-NMR, MS) and elementary analyses.Dedicated to Prof. M. Sidky on the occasion of his 60th birthday 相似文献
Trimethyl and triethyl phosphites react with diphenoquinone 3, yielding 4,4′-dihydroxydiphenyl 10; 4′-alkoxy-4-biphenylyl dialkyl phosphates 5, 4,4′-biphenylylene tetraalkyl bis(phosphates), 6, and 4′-hydroxy-4-biphenylyl dialkyl phosphates 9 are also isolated in minor yields. The effect of temperature on the reaction is studied. A mechanism for the reaction is presented which accounts for the experimental results. The reaction of trimethyl and triethyl phosphites with quinoneimines 12 gives the corresponding phosphoramidates 13, in quantitative yields. 相似文献
Following administration of the acidic drug tolmetin (TOL) anaphylactic reactions occurred, which have been hypothesized to be related to the formation of reactive acyl glucuronides. Recently, glutathione adducts have been detected upon incubation of TOL with human liver microsomal preparations, which proved that oxidative activation might also be a pathway of formation of reactive—possibly toxic—glutathione metabolites of TOL. The aim of this work was to develop a new and robust HPLC method to investigate the in vivo effect of 2 coadministered drugs/nutritional supplements on the kinetics of TOL in rats (cimetidine; CIM) known to be a potent inhibitor of CYP3A4, an enzyme that catalyzes the oxidative metabolism and Quercetin; and QUE which induces UGT1A6, an enzyme involved in glucuronidation of acidic drugs. DryLab®, a computer simulation software package, was used to assist in the development and optimization of the HPLC method used for separation of TOL and the two potential kinetic modulators together with three potential internal standards (zomepirac, carvedilol and fexofenadine). The method was validated in biological samples obtained from rats. Non-compartmental pharmacokinetic analysis of data obtained from plasma and rat liver tissue showed significantly higher concentrations of TOL in the presence of CIM; and significantly longer elimination half-life lives in presence of QUE, which implies that drugs or food components interacting with CYP3A4 cause alteration in the metabolic oxidative biotransformation of TOL in vivo leading to accumulation of TOL in the body through a decrease of its clearance. These findings might account for to the side-effects associated with TOL when co-administered with such kinetic modulators.
Abstract UV-irradiation (λ > 313 nm) of o,o-diethyl-o-(3-chloro-4-methyl-coumarin-7-yl)-thiophosphate (Coumaphos; 1) in chloroform results in an regioselective dimerization reaction to afford the head-to-tail anti-dimer 2. The structure of 2 is established by single crystal x-ray diffraction. Singlet oxygen does not affect the formation of 2. 相似文献
Abstract Trialkyl phosphites react with quinisatin (1) and its monohydrate 3 to give the corresponding phosphate derivatives 2a-c. The same compounds are obtained upon reacting 1 and/or 3 with the proper dialkyl phosphite. Structural reasonings based on IR, MS and NMR spectral data, are presented. 相似文献
Three new alternative synthetic strategies based on reactions of hydrazonoyl halides 3 with 2-methylthiouracil 2 and treatment of either 2-pyrimidinyl thiohydrazonates 8 or the diazonium coupling products of active (pyrimidin-2-ylthio)methylene compounds 12 with sodium ethoxide in ethanol are described for the title compounds. The mechanisms and regiochemistry of the studied reactions are discussed. 相似文献
Trialkyl phosphites react with the monohydrates of 1,2,3-indantrione (ninhydrin) (VII) and 1,3-diphenylpropanetrione (VIII) to give the corresponding phosphate derivatives XIa–c and XVIIIa–c. The same compounds are obtained upon reacting VII and/or VIII with the proper dialkyl hydrogen phosphite. The trialkyl phosphites cause the quantitative reduction of perinaphthindantrione (IX) and/or its monohydrate (X) producing dihydroxy-peri-naphthindenone (XXI). On the other hand, dialkyl hydrogen phosphites add to IX (or X), yielding compounds XXIIa–c. 相似文献
The aim of the present study is the simulation of the particulate flow in spiral separators. The study is based on Eulerian approach and turbulence modeling. The results focus on particulate-flow characteristics such as the velocity, the distribution, and concentration of particulates on the spiral trough. The predicted results are compared with the experimental findings from LD9 coal spiral. The comparison shows good agreement and indicates that the most accurate turbulence model is RNG K–ε. 相似文献