Synthesis of aminothiazole derived morphinans

Two aminothiazole derived morphinans 9 and 11 were prepared for our ongoing opioid ligands study. The synthesis was initiated from levorphanol 1, which was first triflated, and then subjected to Pd-catalyzed reduction followed by nitration. The resulting two nitrated isomers were characterized by analogy to known compounds. The formation of the aminothiazole ring occurred highly selectively to yield only one product from each of the anilines 6 and 7.