3-({(2S)-2-[(tert-butoxycarbonyl)amino]propyl}oxy)isoxazole-5-carboxylic acid   、                                                                                      
4-氨基间苯二酚 盐酸盐                                                                                                                                                                                                                                                                                                          以in the same manner as in Example 2, step C, the title compound was obtained的产率得到tert-butyl [(1S)-2-({5-[(2,4-dihydroxyphenyl)carbamoyl]isoxazol-3-yl}oxy)-1-methylethyl]carbamate