A series of condensation products of 1-aryl-4-hydrazinecarbonyl-2-pyrrolidinones with acetone, 2,4-pentanedione, and aromatic aldehydes was obtained and identified by the combination of IR, mass and 1 H, 13 C NMR spectroscopy. The results of their structural studies by NMR spectroscopy are provided. It was ascertained that the presence of the NH group determines the existence of the mixtures of the Z/E-isomers of compounds under study. The availability of Z-isomer as a sterically favorable one was also verified by computer molecular modeling.The products of condensation of carbohydrazides with carbonylic compounds -hydrazones -and its ring-closure reactions are well known and have been thoroughly studied. Compounds of these types are important for both chemical and pharmacological purposes and show analgetic, antidepressive, and bactericidal activities [1]. 1-Aryl-substituted 4-carboxy-2-pyrrolidinones and their salts, esters, amides, and nitriles are plant growth stimulators [2]. The first nucleophilic reaction used in this work was hydrazinolysis of the ester function. Acid hydrazides 2a-c were prepared from the corresponding esters 1a-c and hydrazine monohydrate in refluxing 2-propanol (Scheme 1).Condensation of compounds 2a-c with acetone gave the corresponding isopropylidenehydrazinecarbonyl-2-pyrrolidinones 3a-c, and the one -2b with aromatic aldehydes -1-aryl-4-arylidenehydrazinecarbonyl-2-pyrrolidinones 5-9. 1-Aryl-4-[(3,5-dimethylpyrazol-1-yl)carbonyl]-2-pyrrolidinones 4a-c were synthesized by condensation of hydrazides 2a-c with 2,4-pentanedione in 2-propanol in the presence of a catalytic amount of hydrochloric acid.N-Substituted hydrazones 10-12 were obtained in good yields by alkylation of 1-aryl-4-arylidenehydrazinecarbonyl-1-pyrrolidinones 5, 6 and 8 with ethyl iodide in the presence of potassium hydroxide and potassium carbonate with excess of ethyl iodide without solvent.The structure of the studied compounds 3-12 was elucidated by the methods of IR, mass and 1 H, 13 C NMR spectroscopy. Because of the different nature of fragments of the molecules of the tentative compounds their structural features were mostly unfolded by 1 H, 13 C NMR spectroscopy. Investigation of such structural fragments revealed information concerning the relation between the effects of substituents, their steric arrangement, and the possibility to participate in hydrogen bonding and conjugation. The signals in the NMR spectra were assigned [3, 4] on the basis of chemical shift theory, multiplicities, signal intensities, and comparison with suitable model compounds. The assignment was confirmed by 13 C NMR APT spectra. The results obtained are given in Tables 2-5. The identification of aromatic carbons in the 13 C NMR spectra __________________________________________________________________________________________

A series of 1,4-disubstituted 2-pyrrolidinones was synthesized by condensation of 1-aryl-4-hydrazinecarbonyl-2-pyrrolidinones with aromatic aldehydes, acetone, 2-butanone, and 2,4-pentane-dione. Most of the reaction products have isomers owing to the amide and azomethine structural units in their molecules. Computer molecular modeling was used to study individual features of each isomer. The structures of the synthesized compounds were unambiguously elucidated by combining IR, mass, 1 H, and 13 C NMR spectroscopy on the basis of the theoretical characteristics derived from molecular modeling. In this work the NMR spectra of the studied compounds 3-9 revealed a successful choice of the representative examples and good support for the explication of the peculiarities of s-cis and s-trans isomers formed in amides by the existence of E/Z-configurations in azomethine fragments using solvents of different polarity. Data for the complete NMR assignments are presented.

Pyrimidine derivatives R 0510 Synthesis and Properties of Methyl Hydropyrimidineacetates. -The hydrolysis of title compounds (III) and their condensation with o-phenylenediamine are studied. -(BROKAITE, K.; MICKEVICIUS*, V.; MIKULSKIENE, G.; Chem. Heterocycl. Compd. (N. Y.) 43 (2007) 7, 926-935; Kaunas Univ. Technol., Kaunas 50254, Lithuania; Eng.) -H. Toeppel 12-165

The reactions of N-containing heterocycles with dihaloalkanes were studied. All structures were determined by NMR and mass techniques.

The alkylation of 1-aryl-substituted dihydro-2,4(1H,3H)-pyrimidinediones with methyl 2-bromoacetate has been studied followed by hydrolysis and condensation of the products with o-phenylenediamine. The compounds have been identified by NMR, and IR spectrometry and mass spectrometry. Structural characteristics in the 1 H and 13 C NMR spectra of the synthesized are discussed.