3-methyl-7-(3-methyl-2-buten-1-yl)-8-[3-(tert-butyloxy-carbonylamino)-piperidin-1-yl]-3,7-dihydro-1H-purine-2,6-dione   、                                                                                      
4-bromomethyl-1-methyl-1H-benzo[c][1,2]thiazine-2,2-dioxide                                                                                                                                                              在
                                                                                                                                                                                 
potassium carbonate                                                                                                                                  作用下,
                                                                                                                以
                                                                                         DMF (N,N-dimethyl-formamide)                                                                                  为溶剂,
                                                                                                                                                    反应 57.0h,
                                                                                                                以59%的产率得到1-[(1-methyl-2,2-dioxo-1H-benzo[c][1,2]thiazin-4-yl)methyl]-3-methyl-7-(3-methyl-2-buten-1-yl)-8-[3-(tert-butyloxycarbonylamino)-piperidin-1-yl]-3,7-dihydro-1H-purine-2,6-dione