1: 4-chloro pyridine hydrochloride With sodium hydroxide in tetrahydrofuran; water 2: With lithium diisopropyl amide in tetrahydrofuran; n-heptane; ethylbenzene T=-78°C; 3: N-Methoxy-N-methyl-benzamide in tetrahydrofuran; n-heptane; ethylbenzene T=-78 - 20°C;

1.1: diisopropylamine; BuLi / diethyl ether; hexane / 4 h / -60 °C 1.2: 90 percent / diethyl ether; hexane / -60 - 20 °C 2.1: CrO3 / acetone / 3 h / 20 °C View Scheme

1: N,N-dimethyl-formamide With trichlorophosphate in 1,2-dichloro-ethane T=0°C; Vilsmeier reaction; 0.25 h; 2: 2-(aminomethylene)-1-phenylbutane-1,3-dione in 1,2-dichloro-ethane T=70°C; Vilsmeier reaction;

1.1: diisopropylamine; BuLi / diethyl ether; hexane / 4 h / -60 °C 1.2: 90 percent / diethyl ether; hexane / -60 - 20 °C 2.1: CrO3 / acetone / 3 h / 20 °C View Scheme

lithium diisopropyl amide in tetrahydrofuran T=-78 - 20°C;

potassium acetate in acetic acid 1 h; Heating;