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Reformatsky reaction of methyl 1-bromocyclopentanecarboxylate with 1-aryl-3-(2-hydroxyphenyl)-prop-2-en-1-ones afforded 6-substituted 4-(2-aryl-2-oxoethyl)-2H,4H-spiro[chromene-3,1′-cyclopentan]-2-ones. A probable reaction mechanism was proposed on the basis of DFT/TZVP quantum chemical calculations.

Ethyl 2-amino-5-(2-aryl-2-oxoethylidene)-4-oxo-1H-4,5-dihydrofuran-3-carboxylates and 2-amino- 5-(2-aryl-2-oxoethylidene)-4-oxo-1H-4,5-dihydrofuran-3-carbonitriles reacted with alcohols in the presence of a catalytic amount of concentrated aqueous HCl to give the corresponding 5-alkoxy-2-amino-5-(2-aryl-2- oxoethyl)-4-oxo-1H-4,5-dihydrofuran-3-carboxylic acid derivatives. A probable reaction mechanism was proposed on the basis B3LYP/6-311G(d) quantum chemical calculations.

Physicochemical properties of 4,5-(aryl, alkyl)-3-substituted 2-sulfonylaminothiophenes have been studied. The effect of the nature of the substituents in the thiophene ring on acid-base properties, solubility, and chemical stability was investigated.

Reformatsky reaction of methyl 1-bromocyclopentane-1-carboxylic acid with 3-aryl-2-cyanoprop-2-enamides and their N-methyl derivatives afforded 10-aryl-6,8-dioxo-7-azaspiro[4.5]decane-9-carbonitriles and 10-aryl-7-methyl-6,8-dioxo-7-azaspiro[4.5]decane-9-carbonitriles, respectively.

Methyl 1-bromocyclohexanecarboxylate reacts with zinc and amides or methylamides of 3-aryl-2-cyanopropenoic acids to give 5-aryl-1,3-dioxo-2-azaspiro[5.5]undecane-4-carbonitriles or 5-aryl-2-methyl-1,3-dioxo-2-azaspiro[5.5]undecane-4-carbonitriles.

A series of substituted amides of 3-carboxypicolinic acid have been synthesized via the interaction of quinolinic acid anhydride with alkyl(aryl)amines. Their structures were studied by 1H and 13C NMR spectroscopy. The direction of the reaction was explained by quantum-chemistry methods. Three compounds demonstrated hemostatic activity. Two substances exhibited anticoagulant properties. Most substances also exhibited weak bacteriostatic activity.

Zinc enolates obtained from substituted 1-aryl-2,2-dibromoalkanones and zinc react with alkyl 3-oxo-1,3-dihydrobenzo[c]oxepine-4-carboxylate to give the alkyl 1-alkyl-1-aroyl-2-oxo-4,8b-dihydro-1H-3-oxabenzo[a]cyclopropa[c]cycloheptene-1a-carboxylate.

Reformatsky reagent generated from methyl 1-bromocyclohexane-1-carboxylate reacted with N-aryl-2-oxochromene-3-carboxamides and N-aryl-6-bromo-2-oxochromene-3-carboxamides to give, depending on the conditions, the corresponding N-aryl-(6-bromo)-4-(1-methoxycarbonylcyclohexyl)-2-oxochroman-3-carboxamides or 3-aryl-(9-bromo)-1,1-pentamethylene-2,3,4,4a,5,10b-hexahydro-1H-chromeno[3,4-c]pyridine-2,4,5-triones. The products were isolated as a single diastereoisomer.

Zinc enolates formed from 1-aryl-2-bromo-2-phenylethanones and zinc react with dimethyl 2-(1-arylmethylene)malonates to afford dimethyl 2-(1,3-diaryl-3-oxo-2-phenylpropyl)malonates. The latter react with cyclohexylamine, piperidine, or morpholine to give the corresponding monosubstituted amides. The zinc enolate derived from 2-bromoindanone and zinc reacts with dimethyl 2-(4-bromobenzylidene)malonate, yielding dimethyl 2-[(4-bromophenyl)(1-oxoindan-2-yl)methyl]malonate. The final products largely form as a single diastereomer.

Aroylketenes, generated by the thermolysis of 5-aryl-2,3-dihydro-2,3-furandiones, react with S-methyl-N-cyano-N′-phenylisothiourea, N-cyano-N′,N′-dimethylformamidine, and N,N-bis(β-cyanoethyl)-cyanamide with the formation of 6-aryl-2-[(methylthio)(phenylamino)methylene]amino-, 6-aryl-2-dimethylaminomethyleneamino-, and 6-aryl-2-[N,N-bis(β-cyanoethyl)amino]-4H-1,3-oxazin-4-ones respectively. Modeling has been carried out of the interaction of benzoylketene with the indicated cyano compounds by the SSP MO LCAO semiempirical method using the MNDO-PM3 approach. A mechanism is proposed for the formation of substituted 4H-1,3-oxazin-4-ones.

We have used X-ray diffraction to establish the structure of 6-p-tolyl-2-triphenylphosphinimino-4H-1,3-oxazin-4-one. We have modeled its formation from 5-p-toluoylketene and N-cyanotriphenylphosphinimine using the semiempirical SCF MO LCAO method in the MNDO-PM3 approximation. We show that the reaction occurs according to a concerted mechanism.

Zinc enolates formed from 1-aryl-2-bromoalkanones react with methyl esters of substituted 2-oxochromene-3-carboxylic acids to give methyl esters of 6-bromo- or 6,8-dibromo-4-(2-aryl-2-oxo-1-R- ethyl)-2-oxochromane-3-carboxylic acids as mixtures of two diastereomers.

As reported previously, 1-substituted 4-acyl-5-arylpyrrolidine-2,3-diones possess antiinflammatory [1], analgesic [2], antiviral [3], nootropic [2], and antibacterial activity [4]. In continuation of the search for biologically active compounds in the class of substituted pyrrolidine-2,3-diones, we have attempted at introducing a substituent, whose structure is significantly different from that of acyl group, into position 4. The aim was to study how this structural change will modify the chemical properties and antibacterial activity of pyrrolidine-2,3-diones. In this context, we have studied the reactions of 1-aryl5-methyl-5-ethoxycarbonylpyrrolidine-2,3-diones (I – V) with aryldiazonium salts. The results showed that treatment of compounds I – V with aryldiazonium chloride in an ethyl alcohol – dioxane mixture leads to the formation of 4-arylhydrazones of 1-Aryl-5-methyl-5-ethoxycarbonylpyrrolidine-2,3,4-triones (VI – XX). Compounds VI – XX appear as red or orange crystalline substances soluble in ethanol, DMF, and DMSO and insoluble in water. The yields, melting points, and empirical formulas of the synthesized compounds are listed in Tables 1 and 2. The 1 H NMR spectra of compounds VI – XX contain (i) a triplet and a quadruplet from protons of the ethoxy group at = 1.18 – 1.25 and 4.22 – 4.25 ppm, respectively; (ii) a singlet due to the methyl group in position 5 of the heterocycle (1.71 – 1.76 ppm); (iii) signals from aromatic protons (7.00 – 7.77 ppm); and a signal due to protons of the NH group (12.90 – 13.21 ppm). The IR spectra of compounds VI – XX display absorption bands due to lactam and ketone carbonyl groups in the regions of 1710 – 1716 cm –1 , ester carbonyls at 1740 cm –1 , azomethine group at 1653 – 1662 cm –1 , and a band due to the stretching vibrations of NH bonds in the region of 3192 – 3200 cm –1 .

5-Aryl-2-aroylacetyl-1-benzylimidazoles were synthesized by treatment of 5-aryl-2-tosylmethylimino-2, 3-dihydro-3-furanones withN-(benzylidene)benzylamines containing electron-donating substitutents in the benzylidene moiety. The structure of 1-benzyl-5-p)-methoxyphenyl-2-(p-chlorobenzoyl)acetylimidazole was studied by X-ray diffraction.