1: 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,4-dimethyl-1H-pyrazole With sodium hexamethyldisilazane in tetrahydrofuran T=20°C; 0.0833333 h; 2: ethyl iodide in tetrahydrofuran T=70°C; 16 h;

acetic acid T=60°C;

1: bromination-dehydrobromination 2: 98 percent / acetic acid / 60 °C View Scheme

sodium hydroxide; monohydrazine sulfate