Abstract：
:Zaleplon is a pyrazolopyrimidine derivative and possesses sedative and hypnotic properties. Seven unknown impurities in zaleplon bulk drug at levels below 0.1% were detected by reverse-phase high performance liquid chromatography (HPLC). The starting material, 3-amino-4-cyanopyrazole and an intermediate, N-[3-[3-(dimethylamino)-1-oxo-2-propenyl]-phenyl]-N-ethylacetamide (DOPEA) were also present in the sample at a level below 0.1%. The molecular weights of impurities were determined by LC-MS analysis. These impurities were isolated from crude samples of zaleplon using reverse-phase preparative HPLC. Based on the spectral data the structures of these impurities were characterized as, N-(3-(3-(4-amino-2H-pyrazolo [3,4-d]pyrimidin-6-yl) pyrazolo[1,5-a] pyrimidin-7-yl)phenyl)-N-ethylacetamide (impurity I); N-[3-(3-carboxamidopyrazolo[1,5-a]pyrimidin-7-yl)phenyl]-N-ethylacetamide (impurity II); N-[3-(3-cyanopyrazolo[1,5-a]pyrimidin-7-yl)phenyl]acetamide (impurity III); N-[3-(3-cyanopyrazolo [1,5-a]pyrimidin-7-yl)phenyl]-N-methylacetamide (impurity IV); N-[3-(3-cyanopyrazolo[1,5-a] pyrimidin-5-yl)phenyl]-N-ethylacetamide (impurity V); N-[3-(3-cyanopyrazolo[1,5-a] pyrimidin-7-yl)phenyl]-N-ethylamine (impurity VI); N-[3-(3-cyano-6-[(E)-3-((N-ethyl-N-acetyl)amino)phenyl-3-oxoprop-1-enyl] pyrazolo[1,5-a]pyrimidin-7-yl) phenyl]-N-ethylacetamide (impurity VII). Structural elucidation of all impurities by spectral data ((1)H NMR, (13)C NMR, MS and IR) and formation of these impurities are discussed in detail.
journal_name
J Pharm Biomed Analjournal_title
Journal of pharmaceutical and biomedical analysisauthors
Bharathi Ch,Prabahar KJ,Prasad ChS,Kumar MS,Magesh S,Handa VK,Dandala R,Naidu Adoi
10.1016/j.jpba.2007.01.051subject
Has Abstractpub_date
2007-05-09 00:00:00pages
101-9issue
1eissn
0731-7085issn
1873-264Xpii
S0731-7085(07)00091-Xjournal_volume
44pub_type
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journal_title：Journal of pharmaceutical and biomedical analysis
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journal_title：Journal of pharmaceutical and biomedical analysis
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journal_title：Journal of pharmaceutical and biomedical analysis
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abstract：:Icariin, the major flavonoid constituent of the traditional Chinese medicine Epimedii Folium, is extensively researched owing to its comprehensive beneficial effects. This study aimed at identifying the in vivo metabolites and the metabolic profiling in rats after oral administration at a dose of icariin (100 mg/kg) w...
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journal_title：Journal of pharmaceutical and biomedical analysis
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