1: N,N-dimethyl-formamide With trichlorophosphate in 1,2-dichloro-ethane T=0 - 20°C; 0.35 h; 2: 1H-pyrrole-2-carboxylic acid benzyl ester in 1,2-dichloro-ethane 0.333333 h; Heating; 3: With sodium acetate in 1,2-dichloro-ethane 0.25 h; Heating; Further stages.;

trichlorophosphate in dichloromethane T=0 - 20°C; Vilsmeier-Haack reaction; 27 h;

1.1: KOH / dimethylsulfoxide 1.2: 100 percent / dimethylsulfoxide / 1 h / 20 °C 2.1: POCl3 / 1,2-dichloro-ethane / 0.35 h / 0 - 20 °C 2.2: 1,2-dichloro-ethane / 0.33 h / Heating 2.3: 62 percent / aq. NaOAc / 1,2-dichloro-ethane / 0.25 h / Heating View Scheme

1.1: KOH / dimethylsulfoxide 1.2: 100 percent / dimethylsulfoxide / 1 h / 20 °C 2.1: POCl3 / 1,2-dichloro-ethane / 0.35 h / 0 - 20 °C 2.2: 1,2-dichloro-ethane / 0.33 h / Heating 2.3: 62 percent / aq. NaOAc / 1,2-dichloro-ethane / 0.25 h / Heating View Scheme

potassium permanganate in water; acetone T=20 - 40°C; 2 h;