thionyl chloride; N,N-dimethyl-formamide 8 h; Heating;

1: 90percent H2SO4 / 3 h / 60 - 70 °C 2: 2.) 2M aq. NaOH / 1.) 170 deg C, 1.5 d, 2.) 90 deg C, 5 min 3: 57 percent / 50percent HBF4, NaNO2 / 1.) 0 deg C, 2.5 h, 2.) -20 deg C, 16 h 4: SOCl2, DMF / 8 h / Heating View Scheme

1: 2.) 2M aq. NaOH / 1.) 170 deg C, 1.5 d, 2.) 90 deg C, 5 min 2: 57 percent / 50percent HBF4, NaNO2 / 1.) 0 deg C, 2.5 h, 2.) -20 deg C, 16 h 3: SOCl2, DMF / 8 h / Heating View Scheme

1: 57 percent / 50percent HBF4, NaNO2 / 1.) 0 deg C, 2.5 h, 2.) -20 deg C, 16 h 2: SOCl2, DMF / 8 h / Heating View Scheme