Alright, after some testing, here we go:
AOBD2:
#Modifying AOBD research
#Ore Purification
mods.thaumcraft.Research.moveResearch("PUREORE", "ALCHEMY", -6, 7);
mods.thaumcraft.Research.clearPrereqs("PUREORE");
mods.thaumcraft.Research.addPrereq("PUREORE", "PUREGOLD", false)...