Synthesis of triazine dendrimers

The synthesis of dendrimers with a 1,3,5-triazine ring at the branch point by the convergent technique was investigated. First, 2,4dichroro-6-(p-nitro anilino)-1,3,5-triazine (DCNT) was obtained by the reaction of cyanuric chl oride with p-nitroaniline. Subsequently, DCNT was subjected to the reaction with two folds of aniline followed by the reduction of NO2 group giving ri se to the first generation dendron (G 1-A) having reactive NH2 group at the focal point. The second generation dendron (G 2-A) was also secured by the analogous reaction of DCNT with G 1-A. Although the reaction of DCNT with G2-A afforded a mixture of G 3-N (1 :2 adduct) and 1 : 1 adduct, the direct reduction of these crude products provided the third generation dendron (G 3-A) in low yield. The dendrimers up to the second genaration ([G 2](3)-C) could ultimately be synthesized by the coupling of each dendron with cyanu ric chloride. Since the obtained dendrimers have imine-like nitrogen-linked 1,3,5-triazine and benzene rings alternately, they were supposed to be rel atively planar. The characteristics of triazine dendrimers are also describ ed.