Novel Stilbene-triazine Symmetrical Optical Brighteners: Synthesis and Applications

A series of new high light fastness, hot pressing fastness optical brighteners was efficiently synthesized by a three-step approach involving the successive replacement of the three chloro groups of 2,4,6-trichloro-1,3,5-triazine under different conditions of temperature and pH. Thus, 2,4,6-trichloro-1,3,5-triazine was treated with different anilines and the resulting dichlorotriazinyl intermediates (3a-I) were further condensed with 4,4-diaminostilbene-2,2′-disulfonic acid to afford bis-monochlorotriazine (5a-I) followed by nucleophilic substitution with ethanolamine to furnish the final hybrid brighteners (7a-I). All of the newly synthesized compounds were characterized by Fourier-Transform Infrared (FT-IR), UV-visible absorption, NMR spectroscopy and the elemental analyses. The synthesized optical brighteners were also assessed for their efficacy as fluorescent brightening agents.     

Water promoted, microwave-assisted oxidative novel deamination of N-aminoquinazolinones

A novel deamination of 2-alkyl/aryl 3-amino-4（3H）-quinazolinones series using aqueous KMnO4 under thermal condition and microwave irradiation is described. Compared to thermal condition, significantly higher yields in much shorter times were observed for reactions under microwave irradiation. A plausible mechanism has been proposed for the oxidative water-promoted deamination.