Ethyl 5-(2,4-bis(benzyloxy)-5-chlorophenyl)-3-(ethylcarbamoyl)-4,5'-biisoxazole-3'-carboxylate   、                                                                                      
三氯化硼                                                                                                                                                              在
                                                                                                                                                                                 crude product   、                                                                                                  silica gel                                                                                                                                  作用下,
                                                                                                                                                                                                                            以to afford the title compound (7.2 mg, 0.017 mmol) in a yield of 48%的产率得到ethyl 5-(5-chloro-2,4-dihydroxyphenyl)-3-(ethylcarbamoyl)-4,5'-biisoxazole-3'-carboxylate