A novel methodology is described for the sampling and analysis of diacetyl, 2,3-pentanedione, 2,3-hexanedione, and 2,3-heptanedione. These analytes were collected on o-phenylenediamine-treated silica gel tubes and quantitatively recovered as the corresponding quinoxaline derivatives. After derivatization, the sorbent was desorbed in 3 mL of ethanol solvent and analyzed using gas chromatography/...

Four new quinoxaline-spanned cavitands having a diester hydrogen phosphate group were successfully synthesised. These phosphorous derivatives applied in Brønsted acid-assisted catalytic conjugate addition reactions. The results ranked with the control of diphenyl as well among those four cavitands. structure–activity relationship revealed that catalyst centre surrounded by two trans-positioned ...

To investigate the cytotoxicity mechanism of quinocetone from the perspective of chemical structure, quinocetone and other new quinoxaline-1, 4-dioxide derivatives were synthesized, and evaluated for their activities, and analysed for the metabolic characteristics. Quinocetone and other new quinoxaline-1,4-dioxide derivatives were synthesized, and evaluated for their activities, and analysed fo...

selectfluor [1-(chloro methyl) -4-flouro -1,4-di azonia bicyclo[2,2,2] octane bis (tetraflouro-borate)] catalyzed the preparation of quinoxaline and 2,3-dihydo pyrazine derivatives through one -pot condensation of 1,2-di amines with 1,2-di carbonyls in solvent and under solvent- free conditions. this catalyst is commercially available, inexpensive, reusable, stable to air and moisture, and rela...