Synthesis of 2,3-Disubstituted 6-Aminoquinoxalines and Their Application to New Fluorescence Derivatization Reagents for Carboxylic Acids
作者:Akira Katoh、Motoki Takahashi、Junko Ohkanda
DOI:10.1246/cl.1996.369
日期:1996.5
Fluorescent 2,3-disubstituted 6-aminoquinoxalines were synthesized by reaction of 2,3-dichloro-6-nitroquinoxaline with some nucleophiles and subsequent catalytic hydrogenation of the nitro group. Further, two of them were demonstrated to be new high-sensitive fluorescence derivatization reagents (1 fmol/1 μl injection volume) for long-chain carboxylic acids.
6-nitro-2,3-dipiperidinoquinoxaline: Its unexpected formation from 2-chloro-7-nitroquinozaline.
作者:J. Nasielski、C. Rypens
DOI:10.1016/s0040-4039(00)79653-5
日期:1991.3
Excess piperidine and 2-chloro-7-nitroquinoxaline 1 in diethyl ether give large amounts of the unexpected disubstitution product 6-nitro-2,3-di-piperidinoquinoxaline 3. The mechanism of this very unusual nucleophilic substitution of hydrogen is suggested to involve the oxidation of the dipiperidino-dihydroquinoxaline 10 by dissolved oxygen.