(R)-4-(2-methylpiperazin-1-yl)-1-phenylpyrido[3,4-d]pyridazine   、                                                                                      
三乙胺   、                                                                                      
二甲氨基甲酰氯                                                                                                                                                                                                                                                                                                          以afforded (R)—N,N,3-trimethyl-4-(1-phenylpyrido[4,3-d]pyridazin-4-yl)piperazine-1-carboxamide 39的产率得到(R)-N,N,3-trimethyl-4-(1-phenylpyrido[4,3-d]pyridazin-4-yl)piperazine-1-carboxamide