3-Benzylamino-4-phenyl-5-nitrobenzoesaeure   、                                                                                      
5-nitro-4-phenyl-3-(pyridin-2-ylmethylthio)benzoic acid                                                                                                                                                                                                                                                                                                          以5-amino-4-phenyl-3-(2-pyridylmethylthio)-benzoic acid is obtained with a melting point of 210°-211° C.的产率得到5-amino-4-phenyl-3-(2-pyridylmethylthio)benzoic acid