1.1: 70 percent / PBu3 / tetrahydrofuran 2.1: 4 Angstroem molecular sieves; cumene hydroperoxide / vanadyl acetylacetonate / CH2Cl2 / 0.5 h / -10 °C 2.2: 86 percent / Bu3P / CH2Cl2 / 0.08 h / -10 °C View Scheme

[2,2']bipyridinyl; 2,2,6,6-tetramethyl-1-piperidinyloxy, free radical; 5,6,9,10-tetrahydro-4H,8H-pyrido[3,2,1-ij][1,6]naphthyridine; oxygen; copper(I) bromide in acetonitrile T=20°C; 16.5 h; Schlenk technique;

pyridine; methanesulfonyl chloride in dichloromethane T=5°C; 18 h; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

diethylzinc

1: With 4-(N,N-dimethlyamino)pyridine; [2,2']bipyridinyl; 2,2,6,6-tetramethyl-1-piperidinyloxy, free radical; oxygen; copper(I) bromide in acetonitrile T=20°C; 13 h; Schlenk technique; 2: With sodium chlorite; sodium dihydrogenphosphate; dihydrogen peroxide in water; acetonitrile T=0 - 20°C; 9.5 h;

Yield given. Multistep reaction;

C30H24N2O7W; dihydrogen peroxide in water; acetonitrile 14 h; Reflux;

dihydrogen peroxide; [3H]-Tetraphenylphosphonium; sodium hydrogencarbonate; WO(O2)2(QO) in acetonitrile T=78°C; 1 h; Product distribution; Further Variations:Temperaturestime;