Search results for "Zole"
showing 10 items of 2482 documents
ChemInform Abstract: Ru(bpy)2Cl2: A Catalyst Able to Shift the Course of the Photorearrangement in the Boulton-Katritzky Reaction.
2016
Abstract The Boulton–Katritzky reaction represents one of the most popular and efficient strategies used to realize azole-into-azole conversions. For example, under different experimental conditions, it allows the rearrangement of Z-arylhydrazones of 3-benzoyl-5-phenyl-1,2,4-oxadiazoles (1) into 2-aryl-4-benzoylamino-5-phenyl-2H-1,2,3-triazoles (2) in very high yields. Moreover, we have recently realized this conversion also by UV-photostimulation. Now we have enlarged the scope of the reaction irradiating with visible or UV light an acetonitrile solution of some Z-arylhydrazones (1a–e) in the presence of catalytic amounts of Ru(bpy)2Cl2. We have observed the unexpected formation of the 1-a…
Studies on the synthesis of heterocyclic compounds. Part IV. Further investigation of the pschorr reaction with some pyrazole derivatives
1980
Thermal decomposition of the diazonium sulfate derived from N-methyl-(1-phenyl-3-methylpyrazol-5-yl)-2-aminobenzamide afforded products formulated as 1-phenyl-3-methyl[2]benzopyrano[4,3-c]pyrazol-5-one (yield 10%), 1,4-dimethyl-3-phenylpyrazolo[3,4-c]isoquinolin-5-one (yield 10%), N-methyl-(1-phenyl-3-methylpyrazol-5-yl)-2-hydroxybenzamide (yield 8%) and 4′-hydroxy-2,3′-dimethyl-1′-phenylspiro[isoindoline-1,5′-[2]-pyrazolin]-3-one (yield 20%). Decomposition of the diazonium sulfate derived from N-methyl-(1,3-diphenylpyrazol-5-yl)-2-aminobenzamide gave products formulated as 7,9-dimethyldibenzo[e,g]pyrazolo[1,5-a][1,3]-diazocin-10-(9H)one (yield 8%), 4-methyl-1,3-diphenylpyrazolo[3,4-c]isoqu…
Antibakterielle Wirkstoffe, 6. Mitt.1) 2,4-Unsymmetrisch dialkylierte Pyrimido[1,2-a]benzimidazole
1982
Durch Kondensation von 2-Aminobenzimidazol (1) mit 2,4-Hexandion (2a) entsteht das Isomerenpaar 3a/3b, mit 6-Methyl-2,4-heptandion (2b) das Isomerengemisch 3c/3d, wahrend mit 1-Phenyl-2,4-pentandion (2c) die Isomere 3e und 3f gebildet werden. Die Trennung der Isomere ist durch Saulenchromatographie, die Strukturfestlegung auf spektroskopischem Wege, moglich. 2-Imino-2H-s-triazino[2,1-b]benzoxazol weist antibakterielle Wirksamkeit auf. Antibacterial Drugs, VI: 2,4-Unsymmetrically Dialkylated Pyrimido[1,2-α]benzimidazoles Condensation of 2-aminobenzimidazole (1) with 2,4-hexanedione (2a) leads to the pair of isomers 3a/3b. Condensation with 6-methyl-2,4-heptanedione (2b) yields the isomers 3c…
Studies in organic mass spectrometry. IV. Electron impact induced fragmentation of 2-substituted 3-(5-isoxazolyl)-4(3H)-quinazolinones of pharmaceuti…
1984
The fragmentation under electron impact of thirteen 2-substituted-3-(5-isoxazolyl)-4(3H)-quinazolinones has been investigated with the aid of metastable ion detection and high resolution measurements. Molecular ions are always abundant and the main primary fragmentation route involves acetonitrile elimination through isoxazole ring opening. The other common processes, particularly those leading to the abundant [R-C8H4N2]+ ion (b or b'), as well as those due to the nature of the 2-substituent are reported and discussed.
ChemInform Abstract: Mass Spectrometry of 3,4-Dihydroquinazolin-4-ones of Pharmaceutical Interest. Part 3. Electron Ionization Mass Spectra of 2-Subs…
2010
The fragmentation reactions induced by electron impact of eighteen title compounds has been investigated with the aid of low beam energy spectra (14 eV, nom. value), metastable ion detection, high resolution measurements and labelling experiments. The loss of the 4-carbonyl oxygen together with the 3-substituent, which constitutes a characteristic fragmentation route of 3-aryl and 3-heteroaromatic substituted-4(3H)-quinazolinones, is again observed, but the presence of a carboxyethyl group at the 4′-position of the pyrazole ring is responsible of an anomalous loss of 47 daltons from the molecular ion. Lastly, a comparison with the previously described behaviour of 3-(5′-isoxazolyl) derivati…
Divide and Protect: Passivating Cu(111) by Cu-(benzotriazole)2
2012
Binding of benzotriazolate anion (BTA) to copper complexes and Cu(111) surface was investigated by density functional theory calculations. [BTACuBTA]1– was found to be a very stable complex that BT...
Task Specific Dicationic Ionic Liquids: Recyclable Reaction Media for the Mononuclear Rearrangement of Heterocycles
2014
Nine functionalized dicationic ionic liquids were used to study the base catalyzed mononuclear rearrangement of (Z)-phenylhydrazone of 3-benzoyl-5-phenyl-1,2,4-oxadiazole into the corresponding triazole at 363 K. Ionic liquids were characterized by the presence of 1-(1-imidazolylmethyl)-3,5-di[1-(3'-octylimidazolylmethyl)]benzene cation, bearing on the structure a neutral imidazole unit as basic functionality. Besides anions generally used for monocationic ionic liquids, such as [Br(-)], [BF4(-)], and [NTf2(-)], also dianions having a rigid aromatic spacer such as 1,4-benzenedicarboxylate, 2,6-naphthalenedicarboxylate, and 1,5- and 2,6-naphthalenedisulfonate were taken into account. Further…
ChemInform Abstract: Synthesis of Trifluoromethylated 2-Benzoyl- and 2-Aminoimidazoles from Ring Rearrangement of 1,2,4-Oxadiazole Derivatives.
2008
Abstract Fluoroalkylated 2-ylamino-imidazoles have been synthesized by reaction of 3-amino-5-phenyl-1,2,4-oxadiazole with fluorinated β-dicarbonyl compounds and subsequent base-induced Boulton–Katritzky Rearrangement (BKR) of the isolated β-enaminocarbonyl intermediate. Alternatively, one-pot reactions performed in the presence of Montmorillonite K10 favoured the condensation at the 3-amino moiety of the oxadiazole and, in some cases, allowed the direct synthesis of 2-benzoylamino-imidazoles. Hydrolysis of 2-benzoylamino-imidazoles easily yielded fluorinated 2-amino-imidazoles targets.
Synthesis of trifluoromethylated 2-benzoyl- and 2-aminoimidazoles from ring rearrangement of 1,2,4-oxadiazole derivatives
2008
Abstract Fluoroalkylated 2-ylamino-imidazoles have been synthesized by reaction of 3-amino-5-phenyl-1,2,4-oxadiazole with fluorinated β-dicarbonyl compounds and subsequent base-induced Boulton–Katritzky Rearrangement (BKR) of the isolated β-enaminocarbonyl intermediate. Alternatively, one-pot reactions performed in the presence of Montmorillonite K10 favoured the condensation at the 3-amino moiety of the oxadiazole and, in some cases, allowed the direct synthesis of 2-benzoylamino-imidazoles. Hydrolysis of 2-benzoylamino-imidazoles easily yielded fluorinated 2-amino-imidazoles targets.
Fluorinated Pyrazoles and Indazoles
2014
The synthesis of fluorine containing pyrazoles has been boosted in the past decades due to the interesting properties that confer these building blocks in pharmaceutical and agricultural active ingredients. There are two main methods for the synthesis of fluorine-containing organic compounds, namely, the direct replacement of an atom or functional group such as diazo, hydroxyl, halogen or hydrogen by fluorine, and the modification of fluorine-containing building blocks. In the case of fluorinated pyrazoles the latter approach is the most commonly applied. This chapter deals primarily with the pivotal procedures that allow the preparation of fluoro- and fluoroalkyl- pyrazoles. Their benzocon…