Abstract: 2-Amino-1-phenylpropanes are useful ideal appetite depressants. Among them, 2-N-ethylamino-1-(m-trifluorornethyl)pheny]propanc (Fenfluramine) is most important.Aconvenient method for the syntheses of these compounds is described in this paper. With benzyl methyl ketone as intermediate, the target compounds were successfully obtained from reductive amination reaction in quite reasonable yields. According to the ¹HNMR,it was found that the product yielded by the approach of Y.A.Larionova[4] was :not 2-N-ethylamino-1-(m-trifluoromethyl)phcnylpropane but its rearranged isomer. The stepwise rearrangement products was carefully examined by ¹HNMRand some improvement in amination was reported.