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1.
Reaction of 1-methyl-5-nitroimidazole-2-carboxyl chloride ( 9 ) with diazomethane afforded 2-diazo-1-(1-memyl-5-nitro-2-imidazolyl)ethanone ( 10 ). Successive rearrangement of compound 10 via Arndt-Eastert rearrangement yielded 1-memyl-5-mtroimidazole-2-acetic acid ( 1 ), which was converted to its corresponding methyl ester 11 with etheral solution of diazomethane. 相似文献
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Extended Hückel theory calculations have been carried out to investigate the possible formation of stable π and σ complexes between olefins and some hydrocarbonylirons postulated as active catalysts in Reppe synthesis. It was found that H2Fe(CO)4 and HFe(CO)4- do not coordinate ethylene, unlike the corresponding CO deficient species H2Fe(CO)3 and HFe(CO)3-, which interact with the olefin to give stable π complexes. Moreover ethylene—H2Fe(CO)3 is more stable than ethylene—HFe(CO)3-, in line with the conclusions based on the experimental results. Stable alkyl intermediates are predicted starting from the coordinatively saturated hydrocarbonyls. 相似文献
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Pyrroles treated with oxalyl chloride produced pyrroleglyoxyloyl chlorides. Unsubstituted and C-alkyl pyrroles gave products stable only at low temperatures. N-Substitution or presence on the ring of an electron withdrawing group (e.g. carbonyl) increased the stability of the glyoxyloyl chlorides considerably. Substitution occurred at the 2-position unless both 2 and 5 positions of the pyrrole nucleus were blocked. When this was the case substitution occurred slowly at position 3. 相似文献
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《Tetrahedron letters》1986,27(3):399-402
The dolastane carbon framework present in isoamijiol(1) is elaborated from the enamine(5) using seven carbon-carbon bond forming reactions, four of which involve free radical intermediates. 相似文献
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Schiff's bases 1 derived from ketones and t-butylamine reacted with diphenyl malonate, diphenyl methyl-malonate and diphenyl phenylmalonate to give 4-hydroxy-2-pyridones 4–6 . Schiff's bases b on reaction with trimethyl methanetricarboxylate afforded 4-hydroxy-3-methoxycarbonyl-2-pyridones 12 . 相似文献
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Nitroimidazoles are of considerable medical and potential agricultural interest as chemotherapeutic agents and potential biocides. The standard route to many 1-substituted nitroimidazoles is the condensation of the conjugate base of the nitroimidazole in a suitable (usually protic) solvent with the appropriate halo compound. Except in a few favourable instances yields are generally low1. 相似文献
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Feasibility routes for thermal plasma production of silicon nitride powders are explored. First, a collation of the various proposed systems from the extant literature is examined. Reactant systems investigated include free silicon, silicon monoxide, silicon dioxide, silicon tetrachloride, silane, and other organosilicon precursors, along with various nitriding and reducing species. The reaction yields of these systems are brought to a common denominator by thermodynamic analysis and a first-step introduction of nucleation kinetics including comparisons against published experiments and the authors' own research. In particular, it is observed that the formation of liquid-phase free silicon in the neighborhood of 2500 K is quite detrimental to silicon nitride yield, and furthermore, a high supersaturation of silicon should always be avoided. 相似文献
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Two 3-acetylpyridazines have been prepared. N-Oxidation of 3-acetylpyridazine ( 6 ) gave only 3-acetylpyridazine 1-oxide ( 7 ). During the N-oxidation of 3-acetyl-6-methoxypyridazine ( 10 ), three primary products, namely, 3-acetyl-6-methoxypyridazine 1-oxide ( 12 ), 3-acetyl-6-methoxy-pyridazine 2-oxide ( 13 ), 3-acetylpyridazin-6-one ( 14 ) and an artifact, 3-methoxypyridazine 1-oxide ( 15 ) were obtained. Furthermore, it has been shown that 3-methoxypyridazine 1-oxide ( 15 ) can be obtained in quantitative yield by treatment of 3-acetyl-6-methoxypyridazine 2-oxide ( 13 ) with dilute sodium hydroxide solution at room temperature. This represents a novel deacylation reaction. Nitration of 3-acetylpyridazine 1-oxide, ( 7 ) gave 3,4-bis(3′-pyridazinoyl)furoxan 1′,1′-dioxide ( 19 ) rather than a simple nitration product. 3-Acetyl-pyridazine ( 6 ) and 3-acetyl-6-methoxypyridazine ( 10 ) also gave furoxans ( 22 and 23 ) upon nitration. 相似文献
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Conjugated acylated chloroenamines 5A,C were available by chlorination of mixtures of acylated enamines 8A,C/9A,C by NCS at 0°C. Nonconjugated chloroenamines 10Aa and 10Ba could be obtained by NCS-chlorination of the conjugated acylenamines 9A,B at low temperature. Reaction of 5Aa-5Ac,5Ae, 5Af with cyanide produced morpholinocyclopropylketones 11A. In two cases aminofurans 12Ad and 12Ca resulted as products of this reaction. More generally amino-aryl-furans 12 were formed by thermolysis of the aryl-cyclopropyiketones 11. Amino-alkyl-furans as 12Ae and 12Af only could be trapped by a Diels-Alder reaction leading to 16Ae and 16Af. Epoxyenamines 29A,B unexpectedly were produced from the interaction of cyanide with the chloroenamines 10Aa and 10Ba. 相似文献
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Samarium(II) iodide was used to access eight- and nine-membered carbocycles via a domino reaction comprised of a Reformatsky reaction followed by a nucleophilic acyl substitution reaction. This method represents a general and efficient approach to a variety of highly functionalized, stereodefined carbocycles. 相似文献
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H. L. Cohen 《Journal of polymer science. Part A, Polymer chemistry》1981,19(12):3269-3284
Polymeric haloethyl acrylates, methacrylates, and methacrylamides, poly(vinyl chloride), poly-(epichlorohydrin), and halohydrins prepared from poly(glycidyl methacrylate), poly(butadiene), and poly(pentenamer) were converted to the corresponding azides. These azides reacted with a variety of acetylenic and olefinic derivatives to give, in most cases, good conversions to the corresponding triazole derivatives. 相似文献
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Crystals of the trans-octahedral complex Co(4-Vpy)4(NCS)2 on being heated below the melting point decompose with liberation of 4-vinylpyridine (Vpy) and concurrent polymerization of the free monomer. The two reactions have been followed by differential scanning calorimetry, thermogravimetry, and optical microscopy. Polymerization is inhibited by inclusion of hydroquinone during recrystallization of the complex. This has allowed the kinetic analysis of the decomposition and polymerization to be simplified. Isothermal mass-loss determinations under reduced pressure (10?2 torr), at various temperatures in the range 120–160°C, on hydroquinone-inhibited crystals corresponded to the loss of up to three molecules of vinylpyridine per molecule of starting complex. With uninhibited crystals over the same temperature range the total number of ligands lost was approximately two with a marked decrease near 175°C owing to rapid polymerization. Isothermal decomposition curves for inhibited and uninhibited crystals approximated to the Avrami-Erofeev equation. Values of n varied with temperature. Activation energies for decomposition and polymerization for both types of crystal were estimated from Arrhenius plots. 相似文献
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Processes that may be considered as sequences of pair collisions giving rise to the stable molecule AB are discussed on the basis of a general method of representing the cross-section of A+BC AB+ + in the impulse approximation via a mean over the initial state of BC. It is shown that such processes resemble the one-step processes considered in part I in not being purely classical in character (contrary to the assumptions of [2]) and in being substantially dependent on the mode of overlap of the wave functionsBC and AB even at high collision energies. The reactions T+H2HT+H, T+D2 DT+D are considered on the basis of the general method. 相似文献
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The reaction of sodium or silver perfluoroalkanesulfinate with nitric acid, nitrous acid or nitrogen dioxide in aqueuos solution gave a moderate yield of N, N-bisperfluoroalkylhydroxylamine accompanied by perfluorocarboxylic acid, amide and nitrosoperfluoroalkane. 相似文献
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Rhodium(II)-catalyzed reactions of aryldiazoacetates can be conducted in the presence of iodide, triflate, organoboron, and organostannane functionality, resulting in the formation of a variety of cyclopropanes or C-H insertion products with high stereoselectivity. The combination of the rhodium(II)-catalyzed reaction with a subsequent palladium(II)-catalyzed Suzuki coupling offers a novel strategy for diversity synthesis. 相似文献