1: 1.) POCl3, 2.) KOAc / 1.) CH2Cl2, reflux, 40 min, 2.) CH2Cl2, water, reflux, 20 min 2: 55 percent / sulfur / various solvent(s) / 2 h / Heating View Scheme

With  potassium acetate; trichlorophosphate  1.) CH2Cl2, reflux, 40 min, 2.) CH2Cl2, water, reflux, 20 min;  Yield given. Multistep reaction;