Bridged cyanine dyes. Part 1. 1-(N-methyl-4-pyridinio)-3-(N-methylpyridylene)cyclopenta-1,4-dienes

1,3-Bis(N-methyl-4-pyridinio)propane is condensed with a series of α-diketones to form deep red monocyanine dyes 8 . In strongly acidic solutions C-protonation occurs at the central carbon atom. A similar condensation with α-ketoesters yields zwitterionic cyanines 12 with extinction coefficients exceeding 10⁵.     

(Z)-2-(1H-咪唑-1-基)-1-(2,3,4-三甲氧基)苯乙酮肟酯的设计与合成

三甲基苯乙酮肟;立体异构体;(Z)-2-(1H-咪唑-1-基)-1-(2;3;4-三甲氧基)苯乙酮肟酯的设计与合成     

Preparation,molecular structures,and characteristic properties of (E)-1-(2-furyl)- and (E)-1-(2-thienyl)-2-(3-guaiazulenyl)ethylenes and (E)-1-(3-furyl)- and (E)-1-(3-thienyl)-2-(3-guaiazulenyl)ethylenes

Wittig reactions of 2-furaldehyde (20) [and thiophene-2-carbaldehyde (21)] with (3-guaiazulenylmethyl)triphenylphosphonium bromide (19) in ethanol containing NaOEt at 25 °C for 24 h under argon give (E)-1-(2-furyl)-2-(3-guaiazulenyl)ethylene (22E) and (E)-1-(2-thienyl)-2-(3-guaiazulenyl)ethylene (23E) in 53 and 36% yields. Similarly, Wittig reactions of 3-furaldehyde (29) [and thiophene-3-carbaldehyde (30)] with 19 under the same reaction conditions as for 20 and 21 afford (E)-1-(3-furyl)-2-(3-guaiazulenyl)ethylene (31E) and (E)-1-(3-thienyl)-2-(3-guaiazulenyl)ethylene (32E) in 32 and 46% yields. Molecular structures and characteristic properties as well as preparation of the title E (i.e., one of the geometrical isomers) forms, with a view to comparative study, are reported. Moreover, reactions of those conjugated π-electron systems with TCNE (=tetracyanoethylene) in benzene [and in DMF (=N,N-dimethylformamide)] at 25 °C for 24 h under argon yield unique products, possessing interesting molecular structures, respectively, whose characteristic properties and crystal structures are documented, also.     

Palladium-catalyzed allylic oxidation of 1-(p-toluenesulfonyl)-2-propene and 1-(trimethylsilyl)-1-(p-toluenesulfonyl)-2-propene

The course of palladium-catalyzed oxidation of a terminal alkene by t-BuOOH or by O₂/H₂O is greatly modified when the allylic carbon bears a p-toluenesulfonyl substituent, and allylic oxidation results. Mechanistic explanations of this observation are proposed.     

4-(Arylaminothiocarbonyl)-1-(1-o-methoxyphenylcarbamido)-ethylpiperazines as anticonvulsants

Several 4-(arylaminothiocarbonyl)-1-(1-o-methoxyphenylcarbamido)-ethylpiperazines were synthesized and evaluated for their anticonvulsant activity against pentylenetetrazol-induced seizures in mice. The ability of substituted piperazines to inhibit in vitro respiratory activity of rat brain homogenates was also determined to study their structure-activity relationship.     

Arylsulfonylureido- und Arylsulfonylamidoacyl-Derivate von Hydroxy- und Oxo-cycloalkanen als potentielle Antidiabetica, 5. Mitt.: (1R)-, (1S)-, (1RS)-3-endo-Tosylureido-borneol und (1R)-3-endo-Tosylureido-isoborneol

Ohne Zusammenfassung

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Arylsulfonylureido- and Arylsulfonylamidoacyl Derivatives of Hydroxy cycloalkanes as potential antidiabetica (V): (1R)-, (1S)-, and (1RS)-3-endo-tosylureido borneol and (1R)-3-endo-tosylureido isoborneol

     

Optically active antifungal azoles. XIII. Synthesis of stereoisomers and metabolites of 1-[(1R,2R)-2-(2,4-difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazol-1-yl)propyl]-3-[4-(1H-1-tetrazolyl)phenyl]-2-imidazolidinone (TAK-456)

1-[(1R,2R)-2-(2,4-Difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazol-1-yl)propyl]-3-[4-(1H-1-tetrazolyl)phenyl]-2-imidazolidinone [(1R,2R)-1: TAK-456] is a new antifungal agent selected as a candidate for clinical trials. The three stereoisomers [(1S,2R)-, (1S,2S)- and (1R,2S)-1] of this compound were prepared as authentic samples to determine the enantiomeric and diastereomeric purity of TAK-456 as well as to compare their in vitro antifungal activity. Pharmacokinetic studies of TAK-456 using rats identified the existence of metabolites in the liver homogenate. The structures of the major metabolites were assigned as 4-hydroxy-2-imidazolidinone (3) and/or 5-hydroxy-2-imidazolidinone (4), based on HPLC and LC/MS/MS analyses. These hydroxylated compounds, 3 and 4, were prepared by reduction of the corresponding imidazolidinediones, 11 and 12, and confirmed to be identical to the metabolites by HPLC. In vitro antifungal activities of the three stereoisomers and the synthesized metabolites were considerably weaker than TAK-456.