lithium diisopropyl amide in tetrahydrofuran T=-20°C; 1 h;

1: 1'-methylspiro[cyclohexa[2,5]diene-1,3'-indolin]-2'-one With lithium diisopropyl amide in tetrahydrofuran T=-40°C; 1 h; 2: methyl iodide in tetrahydrofuran