n-butyllithium; diisopropylamine in tetrahydrofuran; N,N'-dimethyl-N,N'-propyleneurea; hexane T=-78 - 25°C; Inert atmosphere; Product distribution / selectivity;

1: 80 percent / H2 / W 2 Raney nickel / methanol; tetrahydrofuran / 15 h / 100 - 105 °C / 82743.7 Torr 2: 1.) lithium diisopropylamide / 1.) THF, HMPT, -75 deg C, 40 min, 2.) THF, HMPT, -80 deg C to RT, 1.5 h View Scheme

1.1: diisopropylamine; n-butyllithium / hexane; N,N'-dimethyl-N,N'-propyleneurea; tetrahydrofuran / 1 h / -78 °C / Inert atmosphere 1.2: -78 - 25 °C 2.1: diisopropylamine; n-butyllithium / hexane; N,N'-dimethyl-N,N'-propyleneurea; tetrahydrofuran / -78 - 25 °C / Inert atmosphere View Scheme

1.1: chloro-trimethyl-silane / 96 h / 18 - 25 °C / Inert atmosphere 2.1: diisopropylamine; n-butyllithium / hexane; N,N'-dimethyl-N,N'-propyleneurea; tetrahydrofuran / 1 h / -78 °C / Inert atmosphere 2.2: -78 - 25 °C 3.1: diisopropylamine; n-butyllithium / hexane; N,N'-dimethyl-N,N'-propyleneurea; tetrahydrofuran / -78 - 25 °C / Inert atmosphere View Scheme

lithium diisopropyl amide 1.) THF, HMPT, -75 deg C, 40 min, 2.) THF, HMPT, -80 deg C to RT, 1.5 h; Yield given. Multistep reaction. Yields of byproduct given;

1: With Ba(OH)2·8H2O; water in ethanol Inert atmosphereReflux; 2: With hydrogenchloride in water T=18 - 25°C; pH=1 - 2;

barium dihydroxide in methanol; water 18 h; Ambient temperature;