9-{(3AR,4R,6S,6AS)-6-[(ethylamino)carbonyl]-2,2-dimethyltetrahydrofuro[3,4-d][1,3]dioxol-4-yl}-6-[(2,2-diphenylethyl)amino]-9H-purine-2-carboxylic acid   、                                                                                      
N-甲基二环己基胺                                                                                                                                                                                              以
                                                                                         
丁酮                                                                                  为溶剂,
                                                                                                                                                                                        以43.9 kg的产率得到N-cyclohexyl-N-methylcyclohexanamine 6-((2,2-diphenylethyl)amino)-9-((3aR,4R,6S,6aS)-6-(ethylcarbamoyl)-2,2-dimethyltetrahydrofuro[3,4-d][1,3]dioxol-4-yl)-9H-purine-2-carboxylate