草酸   、                                                                                      (2S)-(+)1-(1H-2-carboxamidoindol-4-yl)oxy-3-[(2S,4S)-4-(4-methoxybenzo[b]thiophen-2-yl)-2-methylpiperidinyl]-2-propanol                                                                                                                                                                                              以
                                                                                         
乙酸乙酯                                                                                  为溶剂,
                                                                                                                                                                                        生成                                                 
(2S)-(+)1-(1H-2-carboxamidoindol-4-yl)oxy-3-[(2S,4S)-4-(4-methoxybenzo[b]thiophen-2-yl)-2-methylpiperidinyl]-2-propanol oxalate