4-dimethylaminophenylamine dihydrochloride   、                                                                                      
7-formyl-4-methyl-3-methylthio-2,2-dioxo-1-phenyl-1H-thieno<3,4-c><1,2>thiazine                                                                                                                                                              在
                                                                                                                                                                                 
氢氧化钾                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
乙醇                                                                                  为溶剂,
                                                                                                                                                    反应 4.0h,
                                                                                                                以92%的产率得到4-methyl-3-methylthio-7-(4-N,N-dimethylaminoanilinomethylidene)-2,2-dioxo-1-phenyl-1H-thieno<3,4-c><1,2>thiazine