ethyl 8,9-difluoro-4-methyl-1-oxo-1,4-dihydrobenzo[f] [1,7]naphthyridine-2-carboxylate   、                                                                                      
1-(4-氟苯基)哌嗪   、                                                                                                                                                                                                                                                    在
                                                                                                                                                                                 
二氯甲烷   、                                                                                                  
水   、                                                                                                  
Sodium sulfate-III   、                                                                                                  silica gel                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
二甲基亚砜                                                                                  为溶剂,
                                                                                                                                                            20.0~90.0 ℃
                                                                                                                            、693.27 kPa
                                                                                条件下,
                                                                                                                反应 96.0h,
                                                                                                                以0.77 g of ethyl 9-fluoro-8-[4-(4-fluorophenyl)piperazin-1-yl]-4-methyl-1-oxo-1,4-dihydrobenzo[f][1,7]naphthyridine-2-carboxylate was obtained in the form of yellow crystals, which melted at 300° C.的产率得到ethyl 9-fluoro-8-[4-(4-fluorophenyl)piperazin-1-yl]-4-methyl-1-oxo-1,4-dihydrobenzo[f] [1,7]naphthyridine-2-carboxylate