in tetrahydrofuran T=-78 - 0°C;

1: 4-bromo-3,5-dimethyl-1-phenyl-1H-pyrazole With n-butyllithium; N,N,N',N,-tetramethylethylenediamine in tetrahydrofuran T=-78°C; 5 h; 2: dimethyl(phenyl)silyl chloride in tetrahydrofuran T=-78 - 0°C;