sodium chloride; sulfuric acid in methanol

potassium nitrate in sulfuric acid

potassium hydroxide

1: H2SO4; HNO3 / 130 °C 2: methanol. KOH View Scheme

1: SOCl2 / 0.5 h / Heating 2: Et3N / CH2Cl2 / 0.25 h / Ambient temperature 3: 81 percent / Sn, HCl aq. / 4 h / 50 °C 4: Et3N / CH2Cl2 / 0.25 h 5: 29 percent / TFA / 3 h / Ambient temperature View Scheme

in methanol; argon

1: SOCl2 / 0.5 h / Heating 2: Et3N / CH2Cl2 / 0.25 h / Ambient temperature 3: 81 percent / Sn, HCl aq. / 4 h / 50 °C 4: CH2Cl2 / 0.25 h / Ambient temperature 5: 1.) NaH, 2.) 10percent K2CO3 aq. / 1.) DMF, RT, 30 min, 2.) MeOH, reflux, 15 min 6: 13 percent / Et3N / CH2Cl2 / 0.25 h 7: TFA / 1.) reflux, 2.) 50 deg C, 30 min View Scheme