劳森试剂   、                                                                                      
ethyl 6,7-dimethoxy-4-(3,4-dimethoxyphenyl)-2(1H)-quinolone-3-carboxylate                                                                                                                                                                                              以
                                                                                         
甲苯                                                                                  为溶剂,
                                                                                                                                                    反应 18.0h,
                                                                                                                以to give ethyl 6,7-dimethoxy-4-(3,4-dimethoxyphenyl)-2-mercaptoquinoline-3-carboxylate (5.0 g, 70%) which的产率得到ethyl 6,7-dimethoxy-4-(3,4-dimethoxyphenyl)-2-mercaptoquinoline-3-carboxylate