polyphosphate ester T=110 - 150°C; 1 h;

1: orthopropionic acid triethyl ester With ytterbium(III) triflate in N,N-dimethyl acetamide T=55°C; Inert atmosphere; 2: 3,6-diamino-2,5-dibromo-1,4-hydroquinone With pyridine in dimethyl sulfoxide T=55°C; 2.75 h; Inert atmosphere;

polyphosphate ester T=100°C; 1 h;

1: 74 percent / NH3 / ethanol / 8 h / Heating 2: 90 percent / Na2S2O4, H2O 3: 76 percent / molecular sieves / tetrahydrofuran / 2 h / Heating; molecular sieves 4: 76 percent / polyphosphate ester (PPE) / 1 h / 110 - 150 °C View Scheme

1: 76 percent / molecular sieves / tetrahydrofuran / 2 h / Heating; molecular sieves 2: 76 percent / polyphosphate ester (PPE) / 1 h / 110 - 150 °C View Scheme

n-butyllithium 1.) THF, hexane, -78 deg C, 1 h, 2.) THf, hexane, room temp., 24 h; Yield given. Multistep reaction;

1: 1.) n-butyllithium / 1.) THF, hexane, -78 deg C, 1 h, 2.) THf, hexane, room temp., 24 h 2: 1.) n-butyllithium, 2.) CuI / 1.) THF, hexane, -78 deg C, 1 h, 2.) THF, hexane, room temp., a) 1.5 h, b) 45-50 deg C, 18 h 3: 1.) ZnCl2, 4 N HCl, 2.) Na2CO3, O2 / 1.) ethanol, reflux, 96 h, 2.) room temp., 5 h View Scheme