重氮甲烷   、                                                                                      
5-(4-Chloro-benzoyl)-6-imino-3-methyl-5,6-dihydro-pyrazolo[5,1-b]thiazole-2,7-dicarboxylic acid 2-ethyl ester 7-methyl ester                                                                                                                                                                                              以
                                                                                         
1,4-二氧六环   、                                                                                         
乙醚                                                                                  为溶剂,
                                                                                                                                                                                        以96%的产率得到5-(4-Chloro-benzoyl)-3-methyl-6-[(E)-methylimino]-5,6-dihydro-pyrazolo[5,1-b]thiazole-2,7-dicarboxylic acid 2-ethyl ester 7-methyl ester