重氮甲烷   、                                                                                      
2-Acetyl-5-benzoyl-6-imino-3-methyl-5,6-dihydro-pyrazolo[5,1-b]thiazole-7-carboxylic acid ethyl ester                                                                                                                                                                                              以
                                                                                         
1,4-二氧六环   、                                                                                         
乙醚                                                                                  为溶剂,
                                                                                                                                                                                        以91%的产率得到2-Acetyl-5-benzoyl-3-methyl-6-[(E)-methylimino]-5,6-dihydro-pyrazolo[5,1-b]thiazole-7-carboxylic acid ethyl ester