acetic anhydride; trifluoroacetic anhydride T=100°C; 13 h;

pyridine anschliessendes Erhitzen mit Acetanhydrid;

xylene

phosphorus pentachloride in tetrachloromethane Heating;

acetic anhydride 0.0833333 h; Heating; Yield given;

urea T=170 - 180°C; 0.75 h;

T=170 - 180°C;

2: N2H4+H2O View Scheme

1: pyridine / 3 h / 60 °C 2: 6.38 g / acetic anhydride; trifluoroacetic anhydride / 4 h / 100 °C 3: aluminum amalgam; water / tetrahydrofuran / 3 h / 20 °C 4: 251 mg / trifluoroacetic acid; triethylsilane / CH2Cl2 / 2 h / 0 °C 5: H2 / Pd/C / methanol / 24 h / 760 Torr 6: 700 mg / α-bromoacetophenone; triethylamine; 4-(dimethylamino)pyridine / acetonitrile / 4 h / 20 °C View Scheme

T=177°C; 2 h;