1: piperazine-1-carboxylic acid tert-butyl ester With sodium hydride in DMF (N,N-dimethyl-formamide) T=0 - 20°C; 1 h; 2: [3-(bromomethyl)-phenoxy]dimethyl(1,1-dimethylethyl)silane in DMF (N,N-dimethyl-formamide) T=20°C; 24 h; 3: With water in DMF (N,N-dimethyl-formamide) 0.5 h;