Search results for "DISCOVERY"

Über Basisch substituierte Tryptamine und Tryptophole 2. Mitt.: Über die Synthese in 2-Stellung basisch substituierter Tryptopholderivate

1969

Die Darstellung von 2-(N-Piperidinomethyl)-tryptophol-Derivaten aus 2-Methyltryptophol wird beschrieben. Tryptamines and Tryptophols with basic Substituents, Part II The synthesis of 2-(N-piperidinomethyl)-tryptophol-derivatives from 2-methyltryptophol is described.

Zur Analytik der Mutterkornalkaloide 5. Mitt.: Trennung der hydrierten Alkaloide

1964

The acidity of calix[5]arenes and their linear analogues

1999

Abstract Five new calix[5]arenes containing a single p-nitrophenol unit as the most acidic phenolic unit have been synthesised by (3+2) fragment condensation of a trimer with a p-nitrophenol in the middle with various bishydroxymethylated alkanediyl diphenols. Their first acid constant (pKal) has been determined in 2-methoxyethanol/water (9:1) at 22°C by optical titration. The pKal values are distinctly lower (ΔpKa > 2) than for the trimer, while no difference has been found in comparison to structurally analogous calix[4]arenes. Rigidification of the calix[5]arene skeleton by introducing a single alkanediyl bridge opposite to the p-nitrophenol unit has no effect on pKal. All values are in …

Der Einfluss kondensierter Phosphate auf die Eisen-Resorption

1959

Es sollte untersucht werden, ob die kondensierten Phosphate Tetranatriumpyrophosphat, Natriumtripolyphosphat, Hexametaphosphat, Kaliummetaphosphat und Plasmal die Eisenresorption beeintrachtigen. Als Masstab fur diesselbe galten die Hamoglobin- und Erythrocytenregeneration und die Gewichtszunahme anamischer Ratten. Die Anamie wurde durch Phenylhydrazinhydrochlorid-Injektionen bzw. eine eisenarme Ernahrung (Milchdiat) hervorgerufen. Bei den herrschenden Versuchsbedingungen konnte ein nachteiliger Einflus der getesteten Substanzen auf die Eisenresorption nicht nachgewiesen werden. Auf Grund dieser Versuche und allgemeiner Uberlegungen wurde geschlossen, das dies uberhaupt unter physiologische…

Synthesis of a novel ditopic ligand incorporating directly bonded 1,10-phenanthroline and 2,2′:6′,2″-terpyridine units

2006

Abstract The synthesis of a rigid ditopic ligand incorporating a 1,10-phenanthroline directly connected through its 3-position to the 5-position of a 2,2′:6′,2″-terpyridine is described. The synthesis is based on a series of palladium(0)-catalyzed cross-coupling reactions (Stille and Suzuki couplings) starting from 1,10-phenanthroline and bromo-substituted pyridines.

Zur Frage der Resorption von Polyphosphaten

1965

Zur Klarung der Frage nach der Resorption von Polyphosphaten wurden Losungen von32P-markiertem Diphosphat, Triphosphat und einem Natriumpolyphosphat mit 64% P2O5 Ratten mit der Schlundsonde appliziert. Nach einer Verweildauer von 1, 2, 4, 8 und 16 Std dieser Polyphosphate im Magen-Darmtrakt wurden die Ratten dekapitiert und das erhaltene Frischblut radiometrisch und papierchromatographisch untersucht. Im enteiweisten Vollblut konnten nur Monophosphat und AMP nachgewiesen werden, d. h. es wird ausschlieslich anorganisches Monophosphat resorbiert, das durch enzymatische Aufspaltung der Polyphosphate gebildet wird. Dieses Monophosphat wird dann in die organische Bindung der AMP ubergefuhrt und…

Synthesis of 5-substituted 2,3-dihydrobenzofurans in a one-pot oxidation/cyclization reaction

2011

Variously substituted 2,3-dihydrobenzofurans have been synthesized according to a sequential one-pot oxidation/cyclization procedure between para-aminophenol derivatives and an azadiene. Variously substituted 2,3-dihydrobenzofurans have been synthesized according to a sequential one-pot oxidation/cyclization procedure between para-aminophenol derivatives and an azadiene. © 2011 Elsevier Ltd. All rights reserved.

Radioactively labelled epoxides. Part VI. tritium-labelled mono- and dimethyl substituted phenyl oxiranes (styrene oxides)

1988

Tritium-labelled (E)- and (Z)-2,3-dimethyl-2-phenyl oxirane 4, (E)- and (Z)-2-methyl-3-phenyl oxirane 7 and 2,2-dimethyl-3-phenyl oxirane 11 have been prepared by reduction of the corresponding bromoketones with sodium borotritide to the corresponding bromohydrins followed by cyclization to the oxiranes. These oxiranes were successfully used as diagnostic substrates to distinguish between different forms of epoxide hydrolase and glutathione transferase.

Efficient synthesis of 2-bromo-1-[18F]fluoroethane and its application in the automated preparation of 18F-fluoroethylated radiopharmaceuticals

2001

An efficient synthesis of 2-bromo-1-[18F]fluoroethane from commercially available 1,2-dibromoethane and its integration into an automated preparation device was developed for the routine synthesis of 18F-fluoroethylated radiopharmaceuticals. The precursor 1,2-dibromoethane was reacted with the [18F]fluoride/Kryptofix®2.2.2./carbonate-complex in acetonitrile at 70°C for 3 minutes. The crude reaction mixture was diluted with water, loaded on a LiChrolute ®EN-cartridge, eluated with acetonitrile and passed through an Alumina ®B-cartridge. The method can provide 2-bromo-1-[18F]fluoroethane with 98% radiochemical purity completely free of 1, 2-dibromoethan within 10 min, thus avoiding a purifyin…

A facile route to new potential helicating ligands

1998

Abstract The synthesis of new bitriazolopyridines, 6,6′-disubstituted-2,2′-bipyridines and 2-pyridyl-6-(2-pyridylcarbonyl)-2-pyridylmethanone potential helicating ligands from 3-(2-aryl)-[1,2,3]triazolo[1,5-a]pyridines is described.