Abstract: o-Bis (β-chloroethyl)-aminomethyl-phenylalanine dihydrochloride (I, AT-581) was re- ported to possess significant antitumour activities. Furthermore, in view of the fact that compounds carrying a nitro group in the benzene ring show invariably higher antitumour activity as compared with the corresponding unsubstituted ones and that the electro- negative groups such as nitro can deactivate the chlorine atoms of the mustard grouping, thus decrease its toxicity, the authors synthesized 2-bis-(β-chloroethyl)-aminomethyl-5- nitro-phenylalanine(IV) in which a nitro group was introduced into the benzene ring of AT-581. Besides, 2-bis(β-chloroethyl)-aminomethyl-4-nitrotoluene(IV) was also synthe- sized. 2-Methyl-5-nitrobenzyl chloride (VII) was condensed with diethyl formamido-malo- nate to give diethyl 2-methyl-5-nitrobenzyl formamido-malonate (VIII), and the latter was readily converted to diethyl 2-bromomethyl-5-nitrobenzyl formamido-malonate(X) by N-bromosuccinimide in the presence of a small amount of dibenzoyl peroxide in anhydrous carbon tetrachloride. Treatment of X with diethanolamine afforded diethyl 2-bis(β- hydroxyethyl)-aminomethyl-5-nitrobenzyl formamido-malonate(XI), which was then chlorinated with thionyl chloride in dichloromethane to give the chloride (XII),and the desired product (IV) was obtained by the hydrolysis of XII with concentrated hydro- chloric acid. When compound VII was first treated with diethanolamine and then with thionyl chloride, compound VI was obtained.