(6-oxo-4-[(pyridin-4-ylmethylene)amino]-1,6-dihydropyrimidin-2-ylsulfanyl)phenylazoacetic acid ethyl ester   、                                                                                      
碘甲烷                                                                                                                                                              在
                                                                                                                                                                                 potassium hydroxide                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
乙醇                                                                                  为溶剂,
                                                                                                                                                    反应 6.5h,
                                                                                                                以68%的产率得到(1-methyl-6-oxo-4-[(pyridin-4-ylmethylene)amino]-1,6-dihydropyrimidin-2-ylsulfanyl)phenylazoacetic acid ethyl ester