Selectively C-deuterated indigotins

Selectively C-deuterated indigotins were synthesized from halogenated indig otins la-e as precursors. The described reactions - used already by the anc ient purple dyers - allowed the introduction of D-atoms at defined position s of the indigo molecule. The exchange of halogen atoms by D-atoms was indu ced by UV irradiation of the leuco compounds 2a-c and 3a-c in D2O. The resu lting leuco forms Ja-e were oxidized to the deuterated indigotins 5a-c. Som e conclusions were drawn as to the kinetics of the reaction. The physical p roperties of the new compounds were determined.