sulfuric acid T=0°C;

sodium hydroxide; thionyl chloride 1.) reflux, 2 h, 2.) H2O, CH3OH, RT, 19 h; Yield given. Multistep reaction;

1: 97 percent / oxalyl chloride, DMF / toluene / 1 h / Ambient temperature 2: 95 percent / conc. NH4OH / CH2Cl2 / 24 h / Ambient temperature 3: 74 percent / pyridine / 0.5 h / Ambient temperature 4: 1.) SOCl2, 2.) 1 N NaOH / 1.) reflux, 2 h, 2.) H2O, CH3OH, RT, 19 h View Scheme

1: 95 percent / conc. NH4OH / CH2Cl2 / 24 h / Ambient temperature 2: 74 percent / pyridine / 0.5 h / Ambient temperature 3: 1.) SOCl2, 2.) 1 N NaOH / 1.) reflux, 2 h, 2.) H2O, CH3OH, RT, 19 h View Scheme

1: 82 percent / conc. H2SO4 / 0.08 h / Heating 2: 97 percent / oxalyl chloride, DMF / toluene / 1 h / Ambient temperature 3: 95 percent / conc. NH4OH / CH2Cl2 / 24 h / Ambient temperature 4: 74 percent / pyridine / 0.5 h / Ambient temperature 5: 1.) SOCl2, 2.) 1 N NaOH / 1.) reflux, 2 h, 2.) H2O, CH3OH, RT, 19 h View Scheme

1: 74 percent / pyridine / 0.5 h / Ambient temperature 2: 1.) SOCl2, 2.) 1 N NaOH / 1.) reflux, 2 h, 2.) H2O, CH3OH, RT, 19 h View Scheme

T=200°C;