methanol; boron trifluoride in dichloromethane T=0°C; 2 h;

Multi-step reaction with 3 steps 1: HCl/methanol / 1 h / Heating2: 100 percent / pyridine / 48 h / Ambient temperature3: 1.) KOH / 1.) DMSO, 2.) DMSO, 30 min. 20 deg C