4-{[(2S)-6-bromo-2-ethyl-3-oxo-3,4-dihydroquinoxalin-1(2H)-yl]sulfonyl}phenyl ethyl carbonate 、
碘乙烷 、 (3S)-3-ethyl-6-fluoro-4-[(4-hydroxyphenyl)sulfonyl]-1-propyl-3,4-dihydroquinoxalin-2(1H)-one 以to yield (3S)-7-bromo-1,3-diethyl-4-[(4-hydroxyphenyl)sulfonyl]-3,4-dihydroquinoxalin-2(1H)-one的产率得到(3S)-7-bromo-1,3-diethyl-4-[(4-hydroxyphenyl)sulfonyl]-3,4-dihydroquinoxalin-2(1H)-one