1: trimethylsilyl ethanol With sodium hydride in tetrahydrofuran 2: 2,2,2-trichloro-1-(4-nitro-1H-pyrrol-2-yl)-ethanone in tetrahydrofuran T=20°C; 14 h; Further stages.;

1.1: 55 percent / HNO3; Ac2O / 20 °C 2.1: NaH / tetrahydrofuran 2.2: 97 percent / tetrahydrofuran / 14 h / 20 °C View Scheme