1,3-Benzodioxole-N-phthalimido DL-threo-Droxidopa-d3 is an intermediate in synthesizing DL-threo-Droxidopa-d3 (D689953). It is an isotope labelled compound of DL-threo-Droxidopa (D689950), a synthetic amino acid precursor of Norepinephrine. An antiparkinson.