1: concd HCl / methanol / 4 h / Heating 2: HCl / 2 h / Heating 3: 1.) aq. NaNO2, concd HCl, 2.) H3PO2 / 1.) DMF, 0 deg C, 2.) DMF, 0-5 deg C, 59 h View Scheme

sodium hydroxide in methanol 1 h; Heating;

1: concd HCl / methanol / 4 h / Heating 2: HCl / 2 h / Heating 3: 63 percent / aq. NaOH / methanol / 1 h / Heating View Scheme

1: concd HCl / methanol / 4 h / Heating 2: HCl / 2 h / Heating 3: 1.) aq. NaNO2, concd HCl, 2.) Cu2Cl2, aq. KCl / 1.) acetone, 0-5 deg C, 2.) acetone, a) 0-5 deg C, 2 h, b) 70-80 deg C, 0.5 h View Scheme

1: concd HCl / methanol / 4 h / Heating 2: HCl / 2 h / Heating 3: 1.) a) 43percent HBF4, b) aq. NaNO2 / 1.) 0-5 deg C, a) 10 min, b) 20 min, 2.) 80-140 deg C, 0.5 h 4: 87 percent / aq. NaOH / methanol / 1 h / Heating View Scheme

1: concd HCl / methanol / 4 h / Heating 2: HCl / 2 h / Heating 3: 1.) aq. NaNO2, concd HCl, 2.) Cu2Cl2, aq. KCl / 1.) acetone, 0-5 deg C, 2.) acetone, a) 0-5 deg C, 2 h, b) 70-80 deg C, 0.5 h 4: HCl / 2 h / Heating 5: 70 percent / aq. NaOH, n-Bu4N(HSO4) / CH2Cl2 / 4 h / Ambient temperature 6: 84 percent / aq. NaOH / methanol / 1 h / Heating View Scheme

1: concd HCl / methanol / 4 h / Heating 2: HCl / 2 h / Heating 3: 1.) a) 43percent HBF4, b) aq. NaNO2 / 1.) 0-5 deg C, a) 10 min, b) 20 min, 2.) 80-140 deg C, 0.5 h 4: 75 percent / aq. NaOH, n-Bu4N(HSO4) / CH2Cl2 / 4 h / Ambient temperature 5: 68 percent / aq. NaOH / methanol / 1 h / Heating View Scheme

1: concd HCl / methanol / 4 h / Heating 2: HCl / 2 h / Heating 3: 1.) aq. NaNO2, concd HCl, 2.) H3PO2 / 1.) DMF, 0 deg C, 2.) DMF, 0-5 deg C, 59 h 4: HCl / 1 h / Heating 5: 66 percent / aq. NaOH, n-Bu4N(HSO4) / CH2Cl2 / 4 h / Ambient temperature 6: 71 percent / aq. NaOH / methanol / 1 h / Heating View Scheme