An azyl group of ethylene dianfine was protected by N-tert-butoxyearbonyl．The remaining azyl group then successively reacted with methyl acrylate

ethylene diamine and methyl acrylate again to afford the compound Boc-NH2-(B-COOCH3)4 3(AB4)．The ester groups and the Boc-end group of 3 were transferred to carboxylate 4 and azyl group 5 via hydrolyzation and deprotection respectively．The fan-shape dendron molecules with 16 exterior groups 6 were obtained by condensation of 4 and 5 in the presence of DCC The dumbbell-like dendrimer molecules 7 could expediently prepared by coupling the dendrons with two functional groups of hexanedioyl chloride The paper describes the synthesis procedures

reports the characterization results of FTIR、1H-NMR、13C-NMR and MALDI-TOF Comparing with the PAMAM dendrimers from the divergent method

the synthesized compounds possess accurate structures and few defections.