tert-butyl 3-[(2S)-2-amino-2-methylacetylamino]-1-azetidinecarboxylate   、                                                                                      4-nitrobenzyl [(4-nitrobenzyloxy)carbonylimino-pyrazol-1-ylmethyl]carbamate                                                                                                                                                                                              以
                                                                                         
四氢呋喃                                                                                  为溶剂,
                                                                                                                                                                                        以whereby 1.32 g of the title compound were obtained as an amorphous substance的产率得到tert-Butyl 3-[(2S)-2-[2,3-Di(4-nitrobenzyloxycarbonyl)guanidino]-2-methylacetylamino]-1-azetidinecarboxylate