4-(dimethylamino)-4-phenyl-spiro[cyclohexane-1,8'-(5,6,8,9-tetrahydro-thiopyrano[3,4-b]-7-azaindole)]   、                                                                                      
柠檬酸                                                                                                                                                                                              以
                                                                                         
二氯甲烷   、                                                                                         
乙酸乙酯                                                                                  为溶剂,
                                                                                                                                                    反应 17.0h,
                                                                                                                以92%的产率得到4-(dimethylamino)-4-phenyl-spiro[cyclohexane-1,8'-(5,6,8,9-tetrahydro-thiopyrano[3,4-b]-7-azaindole)] citrate