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James J. Li R. Alan Chrusciel Monica B. Norton David B. Reitz Timothy J. Hagen Sofya Tsymbalov E. Ann Hallinan 《Journal of heterocyclic chemistry》1994,31(6):1689-1696
Lithiation of 8-chlorodibenz[b,f][1,4]oxazepine-10-tert-butylcarbamate ( 1 ) is described. Electrophilic substitution of the resulting N-Boc dibenzoxazepine α- lithioamine 2 with ketones, aldehydes, nitriles, iso-cyanates and imines, followed by an in-situ cyclization, gave fused carbamates 5–26 , fused 2H-imidazol-2-ones 27–29 , fused hydantoins 30–32 , and fused ureas 33–35 , respectively, in 11–66% yield. 相似文献
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Herwig G. Winkler Hagen T. Spath Prof. Dr. Karl Torkar 《Monatshefte für Chemie / Chemical Monthly》1975,106(2):535-545
The phase diagrams of the systems CsN3/Zn(N3)2 and KN3/Zn(N3)2 have been obtained employing the microscopic technique ofL. Kofler andA. Kofler. Within the system CsN3/Zn(N3)2 three eutectics at 148°C, 142°C, and 210°C were found. Besides Cs2Zn(N3)4, melting incongruently in the interval 153°C to 170°C, there exist two further compounds of the most probable composition Cs3Zn2(N3)7 and CsZn2(N3)5, melting congruently at 170°C and 210°C, resp. In the system KN3/Zn(N3)2 there exist two eutectics at 203°C and 172°C and two compounds, one of them, i.e. K2Zn(N3)4, melting congruently at 206°C, the other one, with composition KZn3(N3)7 or KZn4(N3)9, melting incongruently at 210°C.
Mit 8 Abbildungen
Herrn Professor Dr.Heribert Grubitsch zum 70. Geburtstag gewidmet. 相似文献
Mit 8 Abbildungen
Herrn Professor Dr.Heribert Grubitsch zum 70. Geburtstag gewidmet. 相似文献
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Rosenthal SJ Tomlinson I Adkins EM Schroeter S Adams S Swafford L McBride J Wang Y DeFelice LJ Blakely RD 《Journal of the American Chemical Society》2002,124(17):4586-4594
To explore the potential for use of ligand-conjugated nanocrystals to target cell surface receptors, ion channels, and transporters, we explored the ability of serotonin-labeled CdSe nanocrystals (SNACs) to interact with antidepressant-sensitive, human and Drosophila serotonin transporters (hSERT, dSERT) expressed in HeLa and HEK-293 cells. Unlike unconjugated nanocrystals, SNACs were found to dose-dependently inhibit transport of radiolabeled serotonin by hSERT and dSERT, with an estimated half-maximal activity (EC(50)) of 33 (dSERT) and 99 microM (hSERT). When serotonin was conjugated to the nanocrystal through a linker arm (LSNACs), the EC(50) for hSERT was determined to be 115 microM. Electrophysiology measurements indicated that LSNACs did not elicit currents from the serotonin-3 (5HT(3)) receptor but did produce currents when exposed to the transporter, which are similar to those elicited by antagonists. Moreover, fluorescent LSNACs were found to label SERT-transfected cells but did not label either nontransfected cells or transfected cells coincubated with the high-affinity SERT antagonist paroxetine. These findings support further consideration of ligand-conjugated nanocrystals as versatile probes of membrane proteins in living cells. 相似文献
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Egon Fanghnel Hagen Bartossek Ute Baumeister Matthias Biedermann Helmut Hartung 《Journal of heterocyclic chemistry》1998,35(6):1449-1454
The first synthesis of substituted 2,2-dioxo-1-phenyl-1H-thieno[3,4-c][1,2]thiazines 2 and some of their reactions are achieved. Compounds 2 were prepared from the 3,5-dimethyl-1,1-dioxo-1,2-thiazine-4-carbaldehydes 1 by reaction with sulfur and triethyl amine in dimethylformamide under mild conditions. They were characterized spectroscopically and by X-ray structure analysis. The formylation, chlorination and oxidation of 2 are reported. 相似文献
10.
Intensive studies on the diazomethane methylation of the common ribonucleosides uridine, cytidine, adenosine, and guanosine and its derivatives were performed to obtain preferentially the 2′-O-methyl isomers. Methylation of 5′-O-(monomethoxytrityl)-N2-(4-nitrophenyl)ethoxycarbonyl-O6-[2-(4-nitrophenyl)ethyl]-guanosine ( 1 ) with diazomethane resulted in an almost quantitative yield of the 2′- and 3′-O-methyl isomers which could be separated by simple silica-gel flash chromatography (Scheme 1). Adenosine, cytidine, and uridine were methylated with diazomethane with and without protection of the 5′ -O-position by a mono- or dimethoxytrityl group and the aglycone moiety of adenosine and cytidine by the 2-(4-nitrophenyl)ethoxycarbonyl (npeoc) group (Schemes 2–4). Attempts to increase the formation of the 2′-O-methyl isomer as much as possible were based upon various solvents, temperatures, catalysts, and concentration of the catalysts during the methylation reaction. 相似文献