The reaction of 8-(6-bromocaproamido)-6-methoxyquinoline (I) with N-(3-hydroxy-n-butyl)piperazine (II) by means of triethylamine in refluxing benzene gives 8-[6-[4-(3-hydroxy-n-butyl)piperazin-1-yl]-1-oxohexylamino]-6-methoxyquinoline (III), which is reduced with LiAlH4 in refluxing THF