phosphorus pentachloride; ammonia 1.) 25 - 200 deg C, 2.) methanol, 393 K, 2.5 h, bomb; Yield given. Multistep reaction;

Multi-step reaction with 2 steps 1: 96 percent / triethylamine / CH2Cl2 / 1.33 h / -0.1 °C2: 76 percent / phosphorus tribromide / CH2Cl2 / 16 h / Ambient temperature