甲醇   、                                                                                      
1-[9-(4-chlorophenyl)-8-(2-chlorophenyl)-9H-purin-6-yl]-4-methyl-aminopiperidine-4-carboxylic acid amide                                                                                                                                                              在
                                                                                                                                         Amberlyst 15                                                                                                                                                                          作用下,
                                                                                                                                                                                        反应 20.0h,
                                                                                                                以55%的产率得到1-[9-(4-chlorophenyl)-8-(2-chlorophenyl)-9H-purin-6-yl]-4-methylaminopiperidine-4-carboxylic acid methyl ester