2,2,6,6-tetramethylpiperidine-1-oxyl in benzene byproducts: 2,2,6,6-tetramethylpiperidine-1-ol; piperidyl-compound was added to a soln. of complex in C6H6 under N2, themixt. was stirred at room temp. for 30 min, an excess of iodine was add ed; column chromy.;

iodine; sodium acetate in 1,2-dichloro-ethane dropwise addn. of a soln. of Rh-complex to a suspn. of ligand and NaO2CCH3 under Ar, refluxing (48 h), addn. of I2 in two stages, stirring (room temp., 3 h); filtration, concg., chromy. (Al2O3, CHCl3);