triethylamine; thiourea in tetrahydrofuran Ambient temperature;

1: With triethylamine in tetrahydrofuran T=20°C; 0.5 h; PS-DVB resin; 2: in dichloromethane T=100°C; 0.333333 h; PS-DVB resin;

1: 95 percent 2: H2, boric acid / Raney-Ni / methanol; H2O / 4 h / Ambient temperature 3: 82 percent View Scheme

1: 1.) triethylamine / 1.) toluene, 0 deg C, 15 min. 2.) 25 deg C, 16 h 2: 85 percent / B(OH)3, H2 / Raney nickel / methanol; H2O / 2.5 h 3: 77 percent / BF3*O(C2H5)2 / CH2Cl2 / 1 h / 0 °C View Scheme