(3S)-1,3-diethyl-7-fluoro-4-[(4-methoxyphenyl)sulfonyl]-3,4-dihydroquinoxalin-2(1H)-one   、                                                                                      (3S)-3-ethyl-7-fluoro-4-[(4-hydroxyphenyl)sulfonyl]-1-methyl-3,4-dihydroquinoxalin-2(1H)-one                                                                                                                                                                                                                                                                                                          以to yield (3S)-1,3-Diethyl-7-fluoro-4-[(4-hydroxyphenyl)sulfonyl]-3,4-dihydroquinoxalin-2(1 h)-one的产率得到(3S)-1,3-diethyl-7-fluoro-4-[(4-hydroxyphenyl)sulfonyl]-3,4-dihydroquinoxalin-2(1H)-one