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71.
K. A. Frolov V. V. Dotsenko S. G. Krivokolysko V. P. Litvinov 《Russian Chemical Bulletin》2005,54(9):2226-2228
Reactions of (Z)-5-benzylidene-2-thiohydantoin with formaldehyde and primary aromatic amines afforded novel derivatives of imidazo[2,1-b][1,3,5]thiadiazine in 50–69% yields.
Dedicated to Academician N. S. Zefirov on the occasion of his 70th birthday.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2158–2160, September, 2005. 相似文献
72.
Acylation of 6-(1-fluorovinyl)-6-methyl- and 6-(2,2,3,3-tetrafluorocyclobutyl)-4,5-diazaspiro[2.4]hept-4-enes with acetyl chloride proceeds as electrophilic addition to the N(5) atom and is accompanied by opening of the cyclopropane ring to give 1-acetyl-3-(2-chloroethyl)-5-(1-fluorovinyl)-5-methyl- and 1-acetyl-3-(2-chloroethyl)-5-(2,2,3,3-tetrafluorocyclobutyl)-4,5-dihydropyrazoles, respectively. Under the same conditions, acylation of 6-(2,3,3-trifluorocyclobut-1-enyl)-4,5-diazaspiro[2.4]hept-4-ene is not regioselective. The (2-chloroethyl) pyrazolines obtained undergo dehydrochlorination into vinylpyrazolines in the presence of an excess of MeONa in MeOH. The reaction of 4-acetyl-6-(2,3,3-trifluorocyclobut-1-enyl)-4,5-diazaspiro[2.4]hept-5-ene with MeONa results in selective replacement of the F atom at the double bond by a methoxy group.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 419–422, February, 2005. 相似文献
73.
Anton Meller Walter Maringgele Rainer Oesterle 《Monatshefte für Chemie / Chemical Monthly》1980,111(5):1087-1096
The reaction of galliumtrichloride and galliumtribomide resp. with 2,6-dimethyl- and 2,4,6-trimethyl-N-trimethylsilyl-trifluoroacetanilide leads to the trifluoracetanilidodihalogenogallanes1–3. The 2,6,9-trioxa-4,8-diaza-1,5-digalla-bicyclo-[3.3.1]-nonadiene derivatives1 a–3 a are formed probably as by products.N-Trimethylsilyltrifluoroacetamide reacts with galliumtrichloride to yield the trifluoroacetamido-dichlorogallane4.N-Trimethylsilyl-N,N,N-triorganyl-thioureas react with galliumtrichloride under elimination of chlorotrimethylsilane to give the thio-ureido-gallanes5 and6. IfN,N-diorganylureas andN,N-diorganyl-thio-ureas resp. are reacted with galliumtrichloride and methyl-gallium-dichloride resp., the thio-ureido- and ureido-gallanes7–9 are obtained by elimination of hydrogenchloride. The compounds are characterized by analysis and spectral data (NMR:1H,19F; MS; IR). The substances are monomeric in the gas phase, obviously due to internal coordination.
30. Mitt.:W. Maringgele undA. Meller, J. Organomet. Chem., im Druck. 相似文献
74.
A concise and efficient method for the preparation of 6,7-disubstituted-5H-pyrrolo[2,3-b]pyrazines via a palladium-catalyzed heteroannulation is reported. Both conventional and microwave heating were used to perform the reactions, with the latter showing dramatically improved results. 相似文献
75.
Peter LeemingColin A Ray Stephen J SimpsonTimothy W Wallace Richard A Ward 《Tetrahedron》2003,59(3):341-352
Heterodiene [4π+2π] cycloadditions of (S,S)-4,5-diaryl-2-methylene-1,3-dioxolanes 1 to a series of β-amido-α,β-unsaturated carbonyl compounds are diastereoselective (d.r.≥4:1). The products can be purified by trituration or crystallisation and hydrolysed with acid to generate the corresponding β-amido carbonyl compounds, the overall sequence effecting an auxiliary-based enantioselective conjugate addition of an acetate enolate, leading to β-aminoacid derivatives. 相似文献
76.
Merlin C. E. Bandeira Franci D. Prochnow Lúcia K. Noda Norberto S. Gonçalves Isolda Costa Hercílio G. de Melo Joe A. Crayston César V. Franco 《Journal of Solid State Electrochemistry》2004,8(4):244-251
The electropolymerization of trans-[RuCl2(vpy)4] (vpy=4-vinylpyridine) monomer on Nd-Fe-B magnets was studied by electrochemical impedance spectroscopy (EIS). Impedance diagrams obtained during the polymerization process were used to monitor film formation. The EIS results gave insight into the electrochemical phenomena occurring at the magnet surface as the polymerization process progressed. The film structure and morphology were also studied by X-ray photoelectron spectroscopy, scanning electron microscopy and Raman spectroscopy. The Raman spectroscopy results showed that the polymerization takes place at the vinyl groups of the monomer and also that the redox polymer structure is very similar to that of the monomer. The ratio of the intensity of the XPS peaks for fluorine (from the electrolyte PF6
–) and ruthenium present in the film showed that the polymer on Nd-Fe-B contained an equal proportion of Ru2+ and Ru3+, indicating that part of the film is positively charged, i.e. {[RuCl2(vpy)4]+}
n
. 相似文献
77.
The chemical fixation of CO2 with mono-substituted terminal epoxides or cyclohexene oxide to form cyclic carbonates under the ZnCl2/[BMIm]Br catalyst system without using additional organic solvents was achieved in excellent selectivity (>98%) and TOF (5410 h−1) and the catalyst could be used six times almost without losing its catalytic activity and selectivity. Besides, the pure cis-cyclic carbonate of cyclohexene oxide was obtained in this catalyst system. 相似文献
78.
79.
V. F. Traven N. Ya. Podkhalyuzina D. S. Kanevskii 《Chemistry of Heterocyclic Compounds》2003,39(7):866-871
5,7-Dihydroxy-4-methyl- and 5,7-dihydroxy-4-trifluoromethylcoumarins are starting compounds in the synthesis of new 10-methyl-8H-difuro[2,3-f;2,3-h]-8-ones and 10-trifluoromethyl-8H-difuro-[2,3-f;2,3-h]chromen-8-ones with high yields. 相似文献
80.
V. I. Terenin E. A. Sumtsova M. A. Kovalkina S. Z. Vatsadze E. V. Kabanova A. P. Pleshkova N. V. Zyk 《Chemistry of Heterocyclic Compounds》2003,39(11):1487-1491
A series of previously unreported aldehydes has been prepared by the formylation reaction of dipyrrolo[1,2-a;2':,1'-c]pyrazines and their 5,6-dihydro analogs by DMF and phosphorus oxychloride. 相似文献