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: POCl3 / 1,2-dichloro-ethane / 0.35 h / 0 - 20 °C 1.2: 1,2-dichloro-ethane / 0.33 h / Heating 1.3: 62 percent / aq. NaOAc / 1,2-dichloro-ethane / 0.25 h / Heating 2.1: 61 percent / aq. KH2PO4; KMnO4 / 2-methyl-propan-2-ol / 0.58 h / 20 °C View Scheme