1: 52.6 percent / P2O5 / 2 h / Heating 2: 51.2 percent / 10percent Pd/C / 2 h / Heating View Scheme

phosphorus pentoxide 2 h; Heating;

2,2,6,6-tetramethyl-piperidine-N-oxyl; dimethylsulfide; oxygen; copper(I) bromide dimethylsulfide complex; 6,6'-bis(C8F17(CH2)4)-2,2'-bipyridine in chlorobenzene T=90°C;