1: 5-bromo-1-methyl-1H-indazole With n-butyllithium; n-butyl-magnesium chloride in tetrahydrofuran; hexanes; toluene T=-30 - 10°C; 2 h; 2: N,N-dimethyl-formamide in tetrahydrofuran; hexanes; toluene T=-10°C; 1 h; 3: With hydrogenchloride; sodium hydrogencarbonate more than 3 stages;

1: With diisobutyl-aluminum chloride in toluene T=-70 - -60°C; 4.33333 h; 2: With acetic acid in toluene

1.1: potassium carbonate / ethylene glycol dimethyl ether / 5 h / 40 °C 2.1: hydrazine hydrate / Reflux 3.1: sodium hydride / tetrahydrofuran / 1 h / 0 °C 3.2: 2 h / 0 - 20 °C 4.1: n-butyllithium; ethylmagnesium bromide / toluene; tetrahydrofuran / 1 h / -10 °C 4.2: 2 h / -10 - 20 °C View Scheme

1.1: sodium hydride / tetrahydrofuran / 1 h / 0 °C 1.2: 2 h / 0 - 20 °C 2.1: n-butyllithium; ethylmagnesium bromide / toluene; tetrahydrofuran / 1 h / -10 °C 2.2: 2 h / -10 - 20 °C View Scheme

1: diethyl ether; tetrahydrofuran / 2 h / 0 - 20 °C 2: Dess-Martin periodane / tetrahydrofuran / 2 h View Scheme