4-methoxypyridine-N-oxide; Cu(NCMe)4NTf2 in acetonitrile T=82°C; 3 h;

pyridine in benzene Heating;

1: 1.) mCPBA; 2.) trifluoroacetic anhydride / 1.) CH2Cl2, 0 deg C, 1 h; 2.) 0 deg C -> r.t., overnight 2: 80 percent / diethyl ether / 0.5 h / -20 - -17 °C 3: mCPBA / CH2Cl2 / -15 °C 4: 79 percent / pyridine / benzene / Heating View Scheme

1: 80 percent / diethyl ether / 0.5 h / -20 - -17 °C 2: mCPBA / CH2Cl2 / -15 °C 3: 79 percent / pyridine / benzene / Heating View Scheme

1: mCPBA / CH2Cl2 / -15 °C 2: 79 percent / pyridine / benzene / Heating View Scheme

1: 1) diisopropylamine, butyllithium / 1) THF, hexane, 78 deg C, 10 min, 2) THF, HMPA, to r.t. in 10 h 2: 1.617 g / mCPBA / CH2Cl2 / 0.5 h 3: 98 percent / trifluoroacetic anhydride / CH2Cl2 / 12 h 4: 1) Cu(I)I / 1) hexane, 2) THF 5: mCPBA / CH2Cl2 / 0.17 h / -10 °C 6: pyridine / benzene / 1.5 h / Heating View Scheme

1: 98 percent / trifluoroacetic anhydride / CH2Cl2 / 12 h 2: 1) Cu(I)I / 1) hexane, 2) THF 3: mCPBA / CH2Cl2 / 0.17 h / -10 °C 4: pyridine / benzene / 1.5 h / Heating View Scheme