N-{6'-fluoro-4',9'-dihydro-4-butyl-spiro[cyclohexane-1,1'(3'H)-pyrano[3,4-b]indol]-4-yl}-piperidine 、
柠檬酸 以
异丙醇 为溶剂,
以49%的产率得到N-{6'-fluoro-4',9'-dihydro-4-butyl-spiro[cyclohexane-1,1'(3'H)-pyrano[3,4-b]indol]-4-yl}-piperidine 2-hydroxy-1,2,3-propanetricarboxylate