Phosphorus tribromide → US9433622, Dmx-156

Participants

Reaction Steps

Compound 82 (40 mg, 0.10 mmol) was dissolved in MeCN (5 mL). Phosphorous tribromide (50 μL, 0.53 mmol) was added and the reaction mixture was heated under reflux for 0.5 hours. The reaction was cooled to rt and 2-oxopiperazine (100 mg, 0.99 mmol) was added and the reaction mixture stirred at rt for 16 hours. The solvent was removed in vacuo and the residue purified by reverse phase preparative LC-MS. Fractions contained the desired product were combined and the MeOH removed in vacuo. The resulting aqueous solution was frozen (−78° C.) and the solvent evaporated in vacuo (freeze dried). The title compound (3 mg, 6%) was obtained as an off-white solid. LCMS, Rt=6.15 min (MeOH-FA method), m/z 474 (MH+).

Provenance & Evidence