Synthesis of some β-nitro-meso-tetraphenylporphyrin derivatives

A selective electrophilic nitration of meso-tetraarylporphyrin copper(II) and nickel(II) complexes, bearing in meso-aryl rings a variety of substituents (3- NO 2, 3- CH 3, 3- Cl , 2,3,4,5,6-pentafluoro-, and 2,6-dichloro-), is described. The reactions of the above porphyrinates, carried out in CHCl 3 at room temperature, with aqueous HNO 3 (concentration 15-50%), resulted in the formation of the respective mono-β-nitrated products, in good or very good yield (74-93%). All the synthesized compounds were demetallated in CF 3 CO 2 H/H 2 SO 4 mixture to give β-nitro-substituted porphyrin free bases – very versatile substrates for further chemical transformations.