You are trying to use the ceintf command to write constraint equations between the link180 nodes and solid65 elements. This isn't really merging, it's more like just connecting.  If the link180 nodes were coincident with the solid65 nodes you wouldn't need the ceintf, you could actually merge them with the nummrg command. When using ceintf the solid65 elements and link180 nodes need to be selected. So you are missing an nsle command:
esel,s,enam,,180
nsle
esel,s,enam,,65
ceintf
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