1: 3,5-dichloro-2-hydroxy-benzaldehyde With potassium carbonate in DMF (N,N-dimethyl-formamide) 0.5 h; 2: methyl iodide in DMF (N,N-dimethyl-formamide) T=0°C; 1 h; 3: in DMF (N,N-dimethyl-formamide) T=20°C; 19 h;

potassium hydroxide T=30 - 40°C;