bis-trimethylsilyl ether; phosphorus pentoxide in dichloromethane 24 h; Heating;

1: 1) carbonyldiimidazole, 2) NH3 / 1) CH2Cl2, r.t., 2 h, 2) CH2Cl2, 30 min 2: 58 percent / P2O5, hexamethyldisiloxane / CH2Cl2 / 24 h / Heating View Scheme