4,5-Disubstituted 1-(2-aminoethyl)-3-hydroxy-3-pyrrolin-2-ones have been synthesized via reactions of acylpyruvic acid methyl esters with a mixture of an aromatic aldehyde and ethylenediamine. Some of the synthesized compounds display pronounced antiinflammatory and analgesic activity at a relatively low toxicity.Previously, we demonstrated that substituted 3-oxy-3-pyrrolin-2-ones possess pharmacological activity of various types including antimicrobial [1], antiinflammatory [2], analgesic [3], antiviral [4], and nootropic [5]. However, the properties of compounds containing aminoalkyl substituents at position 1 of the heterocycle remained unstudied. For this reason, we have synthesized a series of oxy-3-pyrrolin-2-ones containing 2-aminoethyl residues at position 1 of the heterocycle and studied their antiinflammatory and analgesic properties.The new compounds were obtained using reactions of acylpyruvic acid methyl esters with aromatic aldehydes and ethylenediamine. It was found that reactions between these initial substances in 1,4-dioxane at room temperature lead to the formation of 1-(2-aminoethyl)-3-hydroxy-3-pyrrolin-2-ones (Ia -Ih)., p-(CH 3 ) 2 CHPh (f), 2-furyl (g), 2-thienyl (h); II: R 1 = Me, R 2 = Ph.Compounds Ia -Ih appear as colorless or slightly colored crystalline substances poorly soluble in alcohols, DMSO, and DMF. Compound Ia is only slightly soluble in water. In order to improve the solubility of this compound, we obtained the corresponding hydrochloride via interaction with concentrated hydrochloric acid. The product appeared as a colorless crystalline substance soluble in water, ethanol, DMSO, and DMF. The yields and physicochemical characteristics of the synthesized compounds are presented in Table 1.The proposed structures of the synthesized compounds were confirmed by the results of IR and NMR spectroscopic measurements ( Table 2). The IR spectra of compounds I and II display the absorption bands related to the stretching vibrations of ketone carbonyl groups (1605 -1650 cm -1 ), lactam carbonyl groups (1674 -1704 cm -1 ), enole hydroxy groups (3030 -3061 cm -1 ), and primary (in compound II, protonated) amino groups 3114 -3490 cm -1 . The bands due to enole hydroxy groups are very broad (in the spectrum of compound If, this absorption band is broadened so as to become unobservable).The 1 H NMR spectra of compounds I and II contain signals due to methylene protons of the aminoethyl residue (multiplets at 2.62 -4.01 ppm for C(1)H 2 and 2.85 -3.29 ppm for C (2) H 2 ), methine protons in position 5 of the heterocycle (singlets at 5.25 -5.81 ppm), aromatic protons (a group of lines in the region of 6.32 -7.81 ppm), and protons of the primary amino groups (broad singlets from NH 2 at 7.71 -7.78 ppm for compounds I and from NH 3 at 8.35 ppm for compound II). In addition, there is a signal from protons of the acetyl residue in compounds Ia and II 484 0091-150X/05/3909-0484
