1: 4-fluoroaniline With hydrogenchloride; sodium nitrite in water T=-5 - 0°C; 0.25 h; 2: With sodium acetate in water pH=3 - 4; 3: 2-ethylacetoacetic acid ethyl ester With hydrogenchloride; potassium hydroxide more than 3 stages;

1: 4-fluoroaniline With hydrogenchloride; sodium nitrite in water T=0°C; 2: ethyl 3-oxo-hexanoate With potassium hydroxide in ethanol; water T=0°C; pH=5 - 6;

hydrogenchloride; potassium hydroxide; sodium nitrite in ethanol; water T=0°C; 3 h;

hydrogenchloride in water T=70°C; Fischer indole synthesis; 16 h;

1.1: isopropylmagnesium chloride / tetrahydrofuran / 2 h / -20 - 0 °C / Inert atmosphere 1.2: 3 h / 0 - 20 °C / Inert atmosphere 1.3: Inert atmosphere 2.1: hydrogenchloride / water / 16 h / 70 °C View Scheme