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MM. J. Duflos D. Letouz G. Queguiner P. Pastour 《Journal of heterocyclic chemistry》1973,10(6):1083-1084
This communication describes the synthesis of l-methyl-2,3-diformylpyrrole. This new compound is used to prepare a new heterocycle, l-methylcyclohepta[b]pyrrol-6-one and thus allows a new synthesis of l-methylpyrrolo[2,3-d]pyridazine. 相似文献
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MM. P. Duballet A. Godard G. Queguiner P. Pastour 《Journal of heterocyclic chemistry》1973,10(6):1079-1080
This article describes the synthesis of a new heterocycle, pyrido[2,3,f]phtalazine and three new diformylquinolincs. 相似文献
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The synthesis of two new heterocycles is described: pyrido-[2,3-d]-.s-triazolo[ 3,4-f] pyrimidine and pyrido[3,2-d]-.s-triayzolo-[3,4-f] pyrimidine. 4-[I'-Pyrazolyl]pyrido[2,3-d]pyrimidines and 4-[1′-pyrazoly1] pyrido[ 3,2-d] pyrimidine are obtained by the action of 4-hydrazinopyrido[2,3-d]pyrimidine and 4-hydrazinopyrido-[3,2-d]pyrimidine with several β-diketones. 相似文献
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Background
Several studies have shown that Stroop interference is stronger in children than in adults. However, in a standard Stroop paradigm, stimulus interference and response interference are confounded. The purpose of the present study was to determine whether interference at the stimulus level and the response level are subject to distinct maturational patterns across childhood. Three groups of children (6–7 year-olds, 8–9 year-olds, and 10–12 year-olds) and a group of adults performed a manual Color-Object Stroop designed to disentangle stimulus interference and response interference. This was accomplished by comparing three trial types. In congruent (C) trials there was no interference. In stimulus incongruent (SI) trials there was only stimulus interference. In response incongruent (RI) trials there was stimulus interference and response interference. Stimulus interference and response interference were measured by a comparison of SI with C, and RI with SI trials, respectively. Event-related potentials (ERPs) were measured to study the temporal dynamics of these processes of interference.Results
There was no behavioral evidence for stimulus interference in any of the groups, but in 6–7 year-old children ERPs in the SI condition in comparison with the C condition showed an occipital P1-reduction (80–140 ms) and a widely distributed amplitude enhancement of a negative component followed by an amplitude reduction of a positive component (400–560 ms). For response interference, all groups showed a comparable reaction time (RT) delay, but children made more errors than adults. ERPs in the RI condition in comparison with the SI condition showed an amplitude reduction of a positive component over lateral parietal (-occipital) sites in 10–12 year-olds and adults (300–540 ms), and a widely distributed amplitude enhancement of a positive component in all age groups (680–960 ms). The size of the enhancement correlated positively with the RT response interference effect.Conclusion
Although processes of stimulus interference control as measured with the color-object Stroop task seem to reach mature levels relatively early in childhood (6–7 years), development of response interference control appears to continue into late adolescence as 10–12 year-olds were still more susceptible to errors of response interference than adults. 相似文献9.
The reactive species in fluoride-mediated carbon-carbon bond-forming reactions was investigated. The regio- and diastereoselectivities of silanes reacting with cyclohexenone in the presence of a catalytic amount of fluoride was compared to the reactivity of analogous solvent-separated lithium ion pairs. Closely analogous behavior was observed, showing that carbanions and not siliconate complexes are the reactive species in the fluoride-catalyzed reactions. Spectroscopic investigations unambiguously show that phenylthiobenzyl anion will form by reaction of silane with tris(dimethylamino)sulfonium difluorotrimethylsilicate (TASF) or crypt[2.1.1]-solvated lithium enolates. The catalytic cycle runs smoothly with the crypt[2.1.1] complex of alpha-(phenylthio)benzyllithium as the initiator and enolate as the carrier of the desilylation reaction. 相似文献
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Investigation of the antitumour activity of a series of diorganotin dichloride complexes (4-ZC6H4)2SnCl2·L2, where Z = OMe, Me, F, Cl, and CF3 and L2 = 2,2′-bipyridyl (bipy), 1,10-phenanthroline (phen) and 2-aminomethylpyridine (amp) is reported. A number of these complexex are shown to exhibit reproducible activity in vivo towards P388 lymphocytic leukaemia in mice. 1H NMR data are reported for an extended series of (4-ZC6H4)4Sn and the parent dichlorides (4-ZC6H4)2SnCl2 of the above-mentioned complexes. A correlation is reported between Hammett substituent constants and 1H chemical shift data. Attempts are made to relate the antitumour activity of the complexes to various structural factors. The dependence of antitumour activity on the electronic effect of group Z and the nature of the ligand L2 is demonstrated. 相似文献