Synthesis and first characterization of N-alkyldiaminoresorcinols

We report the synthesis and first characterization of N-alkyldiaminoresorcinols (or 4,6-bis-dialkylaminobenzene-1,3-diols C6H2(NHR)2(OH)2) (10a, R = CH2-2-Py; 10b, R = CH2-3-Py; 10c, R = CH2-4-Py) which result from one-pot stepwise reactions: (i) air–oxidation of diaminoresorcinol 3, (ii) transamination reaction leading to the corresponding functional 6π+6π quinonemonoimine zwitterions C6H2(NHR)2(O)2 (9a, R = CH2-2-Py; 9b, R = CH2-3-Py; 9c, R = CH2-4-Py), (iii) reduction and re-aromatization in the presence of the corresponding primary amine bearing a pyridine moiety.