1: 80 percent / methanol / 3 h / Heating 2: 86 percent / 0.1 N HCl / trifluoroacetic acid / 0.5 h / 55 °C 3: 1.) sodium dithionite, 2.) 0.1 N NaOH / 1.) DMF/H2O, 55 deg C, 2.) 1 h View Scheme

1: 80 percent / methanol / 4 h / Heating 2: 86 percent / 0.1 N HCl / trifluoroacetic acid / 55 °C View Scheme