Condensation of Substituted Phenols with Hexakis(methoxymethyl)melamine: Synthesis, Characterization, and Properties of Substituted 2,4,6-Tris[3,4-dihydro-1,3-(2H)-benzoxazin-3-yl]-s-triazine Derivatives

Condensation of hexakis(methoxymethyl)melamine (HMMM) with 2,4-disubstituted and 4-substituted phenols in refluxing p-xylene catalyzed by dinonylnaphthalenedisulfonic acid (DNNDSA) gives substituted 2,4,6-tris[3,4-dihydro-1,3-(2H)-benzoxazin-3-yl]-s-triazine derivatives (1−4). These tris(benzoxazine) derivatives are characterized by infrared, 1H and 13C NMR, mass spectroscopy, and elemental analysis. Differential scanning calorimetry (DSC) studies suggest thermal cross-linking reactions of benzoxazines made from 4-substituted phenols but not for the one made from a 2,4-disubstituted phenol.