5-[1-(2,4-Dichloro-phenyl)-meth-(Z)-ylidene]-4-hydroxy-2-oxo-2,5-dihydro-1H-pyrrole-3-carboxylic acid methyl ester                                                                                                                                                              在
                                                                                                                                                                                 
溴                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
溶剂黄146                                                                                  为溶剂,
                                                                                                                                                    反应 1.0h,
                                                                                                                以85%的产率得到5-[1-Bromo-1-(2,4-dichloro-phenyl)-meth-(Z)-ylidene]-4-hydroxy-2-oxo-2,5-dihydro-1H-pyrrole-3-carboxylic acid methyl ester