the benzyl alcohol in question, 2-amino-5-bromobenzyl alcohol, is obtained from the corresponding benzoic acid via lithium aluminium hydride reduction in tetrahydrofuran. bleah! LAH isn't fun stuff. reacts explosively with water, and in fact the moisture from air is capable of setting the stuff on fire
but the TEMPO oxidation is straightforward. other oxidizing reagents might be expected to attack the aniline ring (aminobenzenes or anilines are notoriously sensitive to oxidation)
TEMPO and its relatives are generally used catalytically, in small quantity. this catalytic quantity of the nitroxyl radical get oxidized _in situ_ to the active oxidizing agent, an N-oxammonium ion, by a co-oxidant present in excess. here? the auxiliary oxidant is simply air. copper(I) trifluoromethanesulfonate, 2,2'-bipyridyl, and N-methylimidazole in acetonitrile form some kind of system here that must bind molecular oxygen usefully so that it can oxidize the TEMPO
well, that's a fun one