1: 44 percent / conc. H2SO4/H2SO4 (20percent SO3) (1:1); H2SO4 (20percent SO3)/100percent HNO3 / 1 h / Heating 2: 95 percent / Na / methanol / 1 h / Ambient temperature 3: 58 percent / PCl3 / CHCl3 / 2 h / Heating View Scheme

1: 44 percent / conc. H2SO4/H2SO4 (20percent SO3) (1:1); H2SO4 (20percent SO3)/100percent HNO3 / 1 h / Heating 2: 36 percent / PCl3 / CHCl3 / 2 h / Heating View Scheme

1: 44 percent / conc. H2SO4/H2SO4 (20percent SO3) (1:1); H2SO4 (20percent SO3)/100percent HNO3 / 1 h / Heating 2: 1.) Na, 2.) PCl3 / 1.) MeOH, 24 h, room temp. 2.) chloroform, 2 h, reflux View Scheme

sulfuric acid; sulfur trioxide; nitric acid 1 h; Heating;

1: 44 percent / conc. H2SO4/H2SO4 (20percent SO3) (1:1); H2SO4 (20percent SO3)/100percent HNO3 / 1 h / Heating 2: 1.) Na, 2.) PCl3 / 1.) MeOH, 24 h, room temp. 2.) chloroform, 2 h, reflux 3: 15 percent / NiCl2*6H2O/(C6H5)3P, Zn, KI / dimethylformamide / 12 h / 50 °C View Scheme

dihydrogen peroxide; acetic anhydride T=80°C; 12 h;

1: 82 percent / 15percent H2O2, conc. HCl 2: 38 percent 3: 54 percent / acetic anhydride, 30percent H2O2 View Scheme

1: 38 percent 2: 54 percent / acetic anhydride, 30percent H2O2 View Scheme

1: 44 percent / conc. H2SO4/H2SO4 (20percent SO3) (1:1); H2SO4 (20percent SO3)/100percent HNO3 / 1 h / Heating 2: 1.) Na, 2.) PCl3 / 1.) MeOH, 24 h, room temp. 2.) chloroform, 2 h, reflux 3: 52 percent / NiCl2*6H2O/(C6H5)3P, Zn, KI / dimethylformamide / 12 h / 50 °C 4: 53 percent / 30percent H2O2, (CH3CO)2O, / 14 h / 100 °C 5: 77 percent / 33percent HBr/CH3COOH / 5 h / Heating View Scheme

1: 44 percent / conc. H2SO4/H2SO4 (20percent SO3) (1:1); H2SO4 (20percent SO3)/100percent HNO3 / 1 h / Heating 2: 1.) Na, 2.) PCl3 / 1.) MeOH, 24 h, room temp. 2.) chloroform, 2 h, reflux 3: 52 percent / NiCl2*6H2O/(C6H5)3P, Zn, KI / dimethylformamide / 12 h / 50 °C View Scheme