Search results for "DISCOVERY"
showing 10 items of 4119 documents
Stereocontrolled approach to quinuclidine derivatives
1998
Abstract Asymmetric Michael-type cyclization of chiral enamino ester (S)-7 furnished the quinuclidinone derivative (3R, 4S)-5, with a high degree of stereoselectivity.
Synthesis and NMR configurational study of imidazo[2,1-b]thiazoles from 1H-1,4-diazepine-7(6H)-thiones
1993
Abstract A thermal intramolecular cyclization of 1-vinyl2,3-dihydro-3 H -imidazole-2-thiones to imidazo[2,1-b]thiazoles is reported. A heteronuclear correlation study of these systems was made in order to establish the configuration of the products.
Iodine oxidative coupling of diene and triene-diolates of unsaturated carboxylic acids.
1991
Abstract Oxidative Coupling of the dianions of unsaturated carboxylic acids 1 , and 4 with iodine, which provides a convenient and facile preparation of γ,γ and e,e-dicarboxylic acids 2 and 5, apparently occurs through SET substitution of intermediate iodo-carboxylates.
Der 2-(4-pyridyl)Ethoxycarbonyl-(4-Pyoc)-rest - eine hydrophile, säure- und basenstabile aminoschutzgruppe für die peptidsynthese
1984
Abstract The title amino blocking function is stable under basic and acidic conditions frequently used in the peptide synthesis. Its hydrophilicity permits an effective peptide synthesis in water. After the easy conversion to the pyridinium form the 4-Pyoc group can be removed by morpholine.
H2-Antihistaminika, 7. Mitt. Synthese und H2-antihistaminische Wirkung N,N′-substituierter Thioharnstoffe, Cyanoguanidine und Dithiooxamide
1981
Es wurden N′-substituierte Thioharnstoffe, Cyanoguanidine und Dithiooxamide mit einem 5-Methyl-4-imidazolyl-methylthioethyl-Substituenten dargestellt und auf H2-antihistaminische Wirksamkeit untersucht. H2-Antihistaminics, VII: Synthesis and H2-Antihistaminic Activity of N,N′-Substituted Thioureas, Cyanoguanidines and Dithiooxamides N′-Substituted thioureas, cyanoguanidines and dithiooxamides with a 5-methyl-4-imidazolylmethylthioethyl substituent were prepared and tested for their H2-antihistaminic activity.
On the electrochemical reduction of carbon dioxide and ethylene
1973
Die gemeinsame Elektrolyse von Athylen (I) und Kohlendioxid (II) liefert je nach den angewandten Bedingungen Mischungen aus Oxalsaure (III) und Bemsteinsaure (IV).
Synthesis of Novel Triazolopyridylboronic Acids and Esters. Study of Potential Application to Suzuki-Type Reactions.
2004
This paper describes a general method for the synthesis of novel [1,2,3]triazolo[1,5-a]pyridylboronic acids and esters, and the first results on Suzuki cross-coupling reactions with these new compounds and [1,2,3]triazolo[5,1-a]isoquinolylboronic acid, reacting with a variety of aryl halides as a route to 7-aryltriazolopyridines and 5-aryltriazoloisoquinolines.
The Renaissance of the 68Ge/68Ga Radionuclide Generator Initiates New Developments in 68Ga Radiopharmaceutical Chemistry
2010
⁶⁸Ge/⁶⁸Ga radionuclide generators have been investigated for almost fifty years now, since the cyclotron-independent availability of positron emitting ⁶⁸Ga via the ⁶⁸Ge/⁶⁸Ga system had always attracted researches working in basic nuclear chemistry as well as radiopharmaceutical chemistry. However, it took decades and generations of research (and researchers) to finally approach a reliable level of ⁶⁸Ge/⁶⁸Ga generator designs, adequate to the modern requirements of radiometal labeling chemistry. ⁶⁸Ga radiopharmacy now is awaking from a sort of hibernation. The exciting perspective for the ⁶⁸Ge/⁶⁸Ga generator, now - more than ever, asks for systematic chemical, radiochemical, technological an…
Unequivocal determination of isomeric products of reaction between 3-methyl-1-phenyl-2-pyrazoline-4,5-dione and aromatic 1,2-diamines
1999
Abstract Regioselectivity of condensation of 3-methyl-1-phenyl-2-pyrazoline-4,5-dione with aromatic 1,2-diamines is dependent on substituent present. Isomeric 3-methyl-1-phenyl-1H-pyrazolo-[3,4-b]-quinoxaline products are distinguished by comparison of their 2D z-gradient selected 1H, 15N HMBC (Heteronuclear Multiple Bond Correlation) spectra. Multiplicity of H5 signal, which is recognizable by the cross-peak for CH3(3)-N4 and H5-N4 interactions, indicates substitution in position 6 or 7. The applied method is expected to be useful for structure determinations in other positional isomers.
H2-Antihistaminika, 25. Mitt. Synthese und H2-antagonistische Wirkung monosubstituierter 1,2,4-Oxadiazol-3,5-diamine
1985
Es wurden die N3- bzw. N5-substituierten 1,2,4-Oxadiazol-3,5-diamine 4a-e und 5a-e dargestellt und auf Histamin-H2-antagonistische Aktivitat untersucht. H2-Antihistaminics, XXV: Synthesis and H2-Antagonistic Activity of Monosubstituted 1,2,4-Oxadiazole-3,5-diamines The N3-or N5-substituted 1,2,4-Oxadiazole-3,5-diamines 4a-e and 5a-e were prepared and tested for histamine H2-antagonistic activity.