hydrogen; nickel in methanol; acetic acid T=25°C; P=3102.97 Torr; 20 h;

1: dibenzyl (R)-1-(1-benzyl-2-hydroxyethyl)hydrazine-1,2-dicarboxylate With hydrogen; acetic acid; nickel in methanol T=20°C; 16 h; 2: phosgene With triethylamine in dichloromethane T=0 - 20°C; Further stages.;