Synthesis of new p-quinone methide containing morpholine fragment: access to (diarylmethyl)phosphonamidates with antitumor activity

Novel (diarylmethyl)phosphonamidates containing 2,6-ditert-butylphenol and heterocycle moieties were synthesized by 1,6-conjugate addition of phosphorylated p-quinone methide with morpholine fragment to 2,6-diaminopyridine or 1,3-diaminobenzene. In the case of an acid-catalyzed reaction of p-quinone methide with sesamol, morpholine was cleaved to form 1,2-benzoxaphosphole substituent. Cytotoxic effects of starting compounds and obtained products were evaluated towards human cancer and normal cells.