A series of N-[b-( p-substituted benzoyl)ethyl]-isoleucine and -methionine derivatives have been synthesized via the alkylation of amino acids with p-substituted b-diethylaminopropiophenone hydrochlorides. Some of the synthesized compounds possess significant antiinflammatory activity.Previously, we have synthesized a studied a series of aand b-aminoketones with a-amino acid residues or their ethyl esters as amine fragments [1] and established that some of these compounds possess local anesthetic, antiinflammatory, antibacterial, and some other types of biological activity. In continuation of our investigations into the synthesis and characterization of arylaliphatic b-aminoketones, we have obtained a series of new compounds (I, II) representing N-[b-( para-substituted benzoyl)ethyl] derivatives of a-amino acids (isoleucine, methionine) and studied their anti-inflammatory and analgesic properties.Compounds I and II were synthesized via interactions of the corresponding amino acids with para-substituted b-diethylaminopropiophenone hydrochloride (III). The reactions proceed on boiling equimolar mixtures of aqueous reactant solutions. The target products I and II are stable crystalline substances. The proposed structures were confirmed by the data of IR and 1 H NMR spectroscopic measurements. The purity of the reaction products was checked by TLC. EXPERIMENTAL CHEMICAL PARTThe IR absorption spectra were measured on a Specord IR-75 spectrophotometer (Germany) using samples prepared as nujol mulls. The 1 H NMR spectra were recorded on a Varian Mercury 300 spectrometer (working frequency. 300 MHz) using TMS as the internal standard. The course of reactions was monitored and the purity of the reaction products was checked by TLC on Silufol UV-254 plates eluted in a mixture of n-butanol, ethanol, acetic acid, and water (8 : 2 : 1 : 3) and developed by treatment with an 0.5% ninhydrin solution in ethanol. The melting temperatures were determined using a Boetius heating stage. The data of elemental analyses agree with the results of analytical calculations using the empirical formulas. The yields and physicochemical characteristics of the synthesized compounds are summarized in Table 1.The initial hydrochlorides of para-substituted b-diethylaminopropiophenones (III) were synthesized using a method described in [2].General method for the synthesis of N-[b-( p-substituted benzoyl)ethyl]-isoleucines (Ia -Id, If, Ih) and -methionines (IIa, IIb, IId -IIf, IIg, IIh). A mixture of (0.01 mole) of a-amino acid and 0.01 mole of para-substi-364 0091-150X/05/3907-0364

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