34121-90-9Relevant academic research and scientific papers
Measurement and prediction of hydrophobicity parameters for highly lipophilic compounds: Application of the HPLC column-switching technique to measurement of log P of diarylpyrazines
Yamagami, Chisako,Araki, Kozue,Ohnishi, Kyoko,Hanasato, Kaoru,Inaba, Haruko,Aono, Masahiro,Ohta, Akihiro
, p. 1299 - 1304 (2007/10/03)
In the preparatory stage of structure-activity relationship (QSAR) studies of anti-platelet aggregant pyrazine derivatives, log P values (P: 1- octanol/water partition coefficient) of diarylpyrazines were measured by a newly developed HPLC column-switching technique. The system consists of two processes: (1) adsorption of the sample at the top end of a short precolumn, and then (2) quantifying the enriched analyte by a conventional analytical column. By using the log P values thus obtained, the correction factor for the steric hindrance caused by the vicinal diphenyl groups was estimated. The log k values (k; retention factor) were also measured with methanol-buffer (pH 7.4) eluents and related to log P. The eluent of 50% methanol content (M50) gave a good linear relationship over a wide range of log P (-0.3 log P 5.2), indicating that log k(M50) parameter is useful for predicting the log P value.
Studies on Pyrazines. Part 27. A New Deoxidative Nucleophilic Substitution of Pyrazine N-Oxides; Synthesis of Azidopyrazines with Trimethylsilyl Azide
Sato, Nobuhiro,Miwa, Naoko,Hirokawa, Noriko
, p. 885 - 888 (2007/10/02)
Azidopyrazines bearing amino, methoxy and/or phenylgroups have been synthesized by reaction of pyrazine N-oxides with trimethylsilyl azide in the presence of diethylcarbamoyl chloride in refluxing acetonitrile.In most cases, the azidation occurs only at t
Condensation Reactions of (1E,3E)-4-Amino-3-cyano-4-methoxy-1-phenyl-2-azabutadiene and Electrocyclizations of Diazatrienes
Freeman, Fillmore,Kim, Darrick S. H. L.
, p. 550 - 552 (2007/10/02)
(1E,3E)-4-Amino-3-cyano-4-methoxy-1-phenyl-2-azabutadiene (2) reacts with 2-methoxypropene in refluxing methylbenzene in the presence of catalytic pyridinium p-toluenesulfonate (PPTS) to give 2-cyano-5,5-dimethyl-3-methoxy-6-phenyl-4,5-dihydro-1,4-diazabe
Photochemical Reactions of Pyrazin-2(1H)-ones
Nishio, Takehiko,Nakajima, Naoko,Kondo, Masaji,Omote, Yoshimori,Kaftory, Menahem
, p. 391 - 396 (2007/10/02)
Irradiation of 1-alkyl-5,6-diarylpyrazin-2(1H)-ones (1a-c) in alcohol under oxygen gave N-alkylacetamide derivatives (2a-e) in 21-69percent yield.The formation of acetamide derivatives (2) arises via the endoperoxide intermediates (3), initially produced by the reaction of the pyrazin-2(1H)-ones (1), which act as their own sensitizer, with singlet oxygen followed by O-O bonds fission, alcohol addition, and rearrangement accompanied by the elimination of the corresponding nitrile derivative.The pyrazin-2(1H)-ones (1a-d) rapidly reacted with singlet oxygen to afford the stable endoperoxides (3a-d).On the other hand, the pyrazin-2(1H)-ones (1a-d) were inert to the photolysis in benzene or methanol under argon.
