1: 5-bromo-6-methyl-1H-indazole With sodium hydride in tetrahydrofuran; mineral oil T=20°C; 0.25 h; 2: methyl iodide in tetrahydrofuran; mineral oil 1.5 h; Cooling with ice;

1.1: toluene / 1 h / 100 °C 2.1: bromine / acetic acid / 3 h / 20 °C 3.1: acetic anhydride; potassium acetate; iso-amyl nitrate / 18-crown-6 ether / chloroform / 3 h / 65 °C 4.1: hydrogenchloride / water; methanol / 1 h / 100 °C 4.2: Cooling with ice 5.1: sodium hydride / tetrahydrofuran; mineral oil / 0.25 h / 20 °C 5.2: 1.5 h / Cooling with ice View Scheme

1.1: bromine / acetic acid / 3 h / 20 °C 2.1: acetic anhydride; potassium acetate; iso-amyl nitrate / 18-crown-6 ether / chloroform / 3 h / 65 °C 3.1: hydrogenchloride / water; methanol / 1 h / 100 °C 3.2: Cooling with ice 4.1: sodium hydride / tetrahydrofuran; mineral oil / 0.25 h / 20 °C 4.2: 1.5 h / Cooling with ice View Scheme

1.1: hydrogenchloride / water; methanol / 1 h / 100 °C 1.2: Cooling with ice 2.1: sodium hydride / tetrahydrofuran; mineral oil / 0.25 h / 20 °C 2.2: 1.5 h / Cooling with ice View Scheme