A convenient and effi cient method was described of the preparation of 2-imino-3-(2-thienyl)-2,5-dihydrofurans by the condensation of α-ketol with the thiophene-2-acetonitrile and some their chemical transformations were performed.3-Functionalized 2(5H)-furanones are relatively wide spread in the nature, they are contained in the composition of many plants and animal bodies and they exhibit a wide range of biologic action [1][2][3][4][5].The theoretical and practical interest is attracted by functionally substituted 2-furanones containing various substituents in the position 3. No compounds were described containing in this position heterocyclic substituents, therefore the development of their synthesis was especially interesting.In extension of the investigation of the synthesis and chemical reactions of new derivatives of iminolactones we carried out in this research the reaction of α-ketols with the thiophene-2-acetonitrile in the presence of sodium ethylate. The reaction proceeds at the equimolar reagents ratio in the presence of the catalytical quantity of the sodium ethylate in anhydrous ethanolover 10 h and results in substituted 2-imino-3-(2-thienyl)-2,5-dihydrofurans Iа-Id in high yields (up to 96%). O Me R 2 OH R 1 H 2 C CN S O Me R 1 R 2 NH S Ia _ IdEtONa R 1 = R 2 = Me (a); R 1 ,R 2 = (CH 2 ) 5 (b); R 1 = Me, R 2 = Et (c); Ph (d).The hydrolysis of 2-imino derivatives Iа-Id provided previously unknown 3-(2-thienyl)-2,5-dihydrofuran-2-ones IIа-IId. The reaction occurred in the presence of acids (pH 4-5) at heating on a water bath for 3 h.Compounds Iа-Id readily formed hydrochlorides at passing the gaseous hydrogen chloride through their benzene solutions. The obtained salts IIIа-IIId were easily transformed into the initial 2-imino derivatives Iа-Id by treating with a solution of potassium carbonate. O Me R 1 R 2 O S IIa _ IId Ia _ Id HCl K 2 CO 3 H + O Me R 1 R 2 NH HCl S IIIa _ IIId .R 1 = R 2 = Me (a); R 1 ,R 2 = (CH 2 ) 5 (b); R 1 = Me, R 2 = Et (c); R 1 = Me, R 2 = Ph (d).It is known that 2-dicyanomethylene derivatives of furans are chromophores, they possess electrooptical and photorefractive properties [6], and are fl uorophores with the fl uorescent characteristics [7].Aiming at the preparation of new dicyanomethylene furan derivatives we studied the reaction of synthesized 2-imino derivatives Iа-Id with malononitrile. The reaction proceeded readily at mixing the initial components in the 1:1 ratio at the room temperature with ammonia evolution and the formation of the corresponding

SHORT COMMUNICATIONS2,5-Dihydrofuran-2-ones having functional substituents in the 3-position constitute structural fragments of many natural and synthetic biologically active compounds [1][2][3][4][5]. One of the most general and convenient methods of synthesis of functionally substituted furan-2(5H)-ones is based on reactions of α-hydroxy ketones with compounds containing an activated methylene group [6][7][8].In continuation of our studies in this field, in the present communication we report on the synthesis and chemical transformations of a new class of compounds, 2,5-dihydrofuran-2-imines based on readily accessible α-hydroxy ketones. We found that, contrary to published data [9], tertiary α-hydroxy ketones react with malononitrile to give mixtures of the corresponding 2,5-dihydrofuran-2-imines I and products of their subsequent reaction with the second malononitrile molecule, 2-(2,5-dihydrofuran-2-ylidene)malononitriles II, which were formed in good yields. Detailed examination of this reaction with a view to find optimal conditions showed that the process occurs even in the absence of a catalyst upon mixing of the reactants in alcohol or benzene.General procedures for the reactions of α-hydroxy ketones with malononitrile. a. The corresponding α-hydroxy ketone and malononitrile, 50 mmol each, were added to a solution of 0.115 g (5 mmol) of metallic sodium in 25 ml of anhydrous ethanol. The mixture was kept for 15-20 h at room temperature, the solvent was distilled off under reduced pressure, the residue was dissolved in benzene, and the precipitate was filtered off and recrystallized from ethanol-water (2 : 1) to isolate compound IIa or IIb. The benzene solution was diluted with four volumes of hexane, and the precipitate was filtered off and recrystallized from heptane. We thus isolated compound Ia or Ib.b. A mixture of 50 mmol of α-hydroxy ketone and 50 mmol of malononitrile in 25 ml of anhydrous ethanol was kept for 15-20 h at room temperature. The mixture was then treated as described above in a. c. A mixture of 50 mmol of α-hydroxy ketone and 50 mmol of malononitrile in 25 ml of anhydrous benzene was kept for 15-20 h at room temperature. The solvent was partially distilled off under reduced pressure, and the mixture was then treated as described above in a. 2-Imino-4,5,5-trimethyl-2,5-dihydrofuran-3-carbonitrile (Ia). Yield 43 (a), 25 (b), 55% (c); mp 97-98°C (oily substance [10]). IR spectrum, ν, cm -1 : 2230 (CN), 1665 (C=N), 1075 (C-O-C), 985 (CH), 890 (CH). 1 H NMR spectrum, δ, ppm: 1.4 s (6H, CH 3 ), 2.20 s (3H, CH 3 ), 6.45 s (1H, NH). Found, %: C 64.01; H 6.48; N 19.01. C 8 H 10 N 2 O. Calculated, %: C 63.98; H 6.71; N 18.65.2-Imino-4-methyl-5,5-pentamethylene-2,5-dihydrofuran-3-carbonitrile (Ib). Yield 38 (a), 17 (b), 60% (c); mp 89-90°C. IR spectrum, ν, cm -1 : 2225 R 1 = R 2 = Me (a), R 1 R 2 = (CH 2 ) 5 (b).

Syntheses on the Basis of 2H-Chromen-2-one and 2H-Chromene-2-thione. -The synthesis of a series of new coumarin derivatives is described. -(AVETISYAN, A. A.; ALVANDZHYAN, A. G.; Russ.

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Synthesis of New Unsaturated Derivatives of Functionally Substituted 2-Imino-2,5-dihydrofurans. -(AVETISYAN, A. A.; ALVANDZHYAN, A. G.; AVETISYAN, K. S.; Russ. J. Org. Chem. 47 (2011) 3, 433-436, http://dx.doi.org/10.1134/s1070428011030183 ; Erevan State Univ., Erevan 375025, Armenia; Eng.) -H. Toeppel