4 A molecular sieve; sodium tris(acetoxy)borohydride in 1,2-dichloro-ethane T=20°C; Cyclization; reductive amination;

T=135°C;

1: 80 percent / DMSO; (COCl)2; Et3N / CH2Cl2 / 0.75 h / -78 - 20 °C 2: 70 percent / 4 Angstroem molecular sieves; sodium triacetoxyborohydride / 1,2-dichloro-ethane / 20 °C View Scheme

1: 83 percent / sat. NaHCO3 / ethyl acetate / 0.33 h / 0 °C 2: 80 percent / DMSO; (COCl)2; Et3N / CH2Cl2 / 0.75 h / -78 - 20 °C 3: 70 percent / 4 Angstroem molecular sieves; sodium triacetoxyborohydride / 1,2-dichloro-ethane / 20 °C View Scheme

in water; acetonitrile 3 h; Heating;

ruthenium(IV) oxide; sodium periodate in tetrachloromethane Ambient temperature;