3(1,3-Heterazolidin-3-yl-methyl)-1,3-oxazolidines and their reduction with borane–THF

Preparation of bis-heterazolidines bonded by a CH₂, CH₂–S–CH₂ or CH₂SCH₂SCH₂ groups through their nitrogen atoms is reported: 3-(1,3-oxazolidin-3-ylmethyl)-1,3-oxazolidine 1, 3-(4,4-dimethyl-1,3-oxazolidin-3-ylmethyl)-1,3-oxazolidine 2, 3-(1,3-diazolidin-3-ylmethyl)-1,3-diazolidine 3, 3-(1,3-thiazolidin-3-ylmethyl)-1,3-thiazolidine 4, 3-(1,3-thiazolidin-3-ylmethylsulfanylmethyl)-1,3-thiazolidine 5 and 3-(1,3-oxazolidin-3-ylmethylsulfanylmethyl-sulfanylmethyl)-1,3-oxazolidine 6. The solid state structures of 4 and 5 were determined by X-ray diffraction analyses. BH₃–THF reduction reactions of compounds 1–6 were investigated. N→BH₃ mono- and di-adducts of 1–6 were prepared and their structures calculated (ab initio 3-21G*).     

Regioselectivity of the hydrolysis of 2-(1-alkoxyvinyl)-substituted imidazolidines, 1,3-thiazolidines,and 1,3-oxazolidines

2-(1-Alkoxyvinyl)-1,3-thiazolidines reacted with H₂O or D₂O in the presence of 105 mol % of p-toluenesulfonic acid or trifluoroacetic acid (20°C, 1 h) to give 2-acetyl-1,3-thiazolidine in quantitative yield. 2-(1-Alkoxyvinyl)-3,5-diphenylimidazolidines underwent hydrolysis in the presence of 20 mol % of an acid (20°C, 24 h) at the vinyloxy group with high regioselectivity yielding 2-acetylimidazolidines. Hydrolysis of 2-(1-alkoxyvinyl)-3-phenyl-1,3-oxazolidines in the presence of 10 mol % of p-toluenesulfonic acid (20°C, 5 days) takes two pathways, one of which involves the endocyclic C-O bond with ring opening and the other involves the vinyloxy group to produce 2-acetyl-3-phenyl-1,3-oxazolidine. Unlike phenyl-substituted 1,3-thiazolidines and imidazolidines, hydrolysis of their 3-methyl- and 3,5-dimethyl-substituted analogs in acid medium occurs mainly via ring opening. The observed hydrolysis pathways were interpreted in terms of B3PW91/6-311G(d,p) quantum-chemical calculations.     

Thermal behavior of syndiotactic E-1,2-poly(3-methyl-1,3-pentadiene)

Syndiotactic E-1,2-poly(3-methyl-1,3-pentadiene) was synthesized with the catalyst system Fe(bipy)₂Cl₂-MAO. The thermal stability and kinetic parameters of degradation were determined by thermogravimetric analysis. The isothermal crystallization kinetics were described by means of the Avrami equation, which suggested a three-dimensional growth of crystalline units, developed by heterogeneous nucleation, followed by a secondary crystallization stage. Syndiotactic E-1,2-poly(3-methyl-1,3-pentadiene) isothermally crystallizes from the melt according to regime II of crystallization described by Lauritzen-Hoffman secondary nucleation theory. Non-isothermal crystallization kinetics were elaborated using different approaches. The equilibrium melting temperature was calculated. The kinetic and thermodynamic data were compared with those obtained from syndiotactic 1,2-poly(1,3-butadiene), which is the first example of 1,2 polydienes family.     

Synthesis of 2-Aryl and 2-Hetaryl Derivatives of 2'-Aminospiro[(1,3-dioxane)-5,5'-thiazolin]-4'-one and Spiro[(1,3-dioxane)-5,5'-thiazolidine]2',4'-dione

2-(Het)aryl derivatives of 2'-aminospiro[(1,3-dioxane)-5,5'-thiazolin]-4'-one or spiro[(1,3-dioxane)-5,5'-thiazolidine]-2',4'-dione are formed by the acid catalyzed interaction of 2-amino-5,5-bis(hydroxymethyl)-4-thiazolinone or its oxo analog 5,5-bis(hydroxymethyl)thiazolidine-2,4-dione with (hetero)aromatic aldehydes.     

Formation of 3-[amino(aryl)-methylidene]-1,3-dihydro-2H-indol-2-ones involving ring transformation of 2-aryl-5-(2-aminophenyl)-4-hydroxy-1,3-thiazoles

The reaction of 3-bromooxindole with substituted (hetero)aromatic thioamides in acetonitrile was studied. At room temperature the reaction preferably gives products of ring transformation i.e. 2-aryl-5-(2-aminophenyl)-4-hydroxy-1,3-thiazoles (3b-f,h) whereas at elevated temperature products of an Eschenmoser coupling reaction, i.e. 3-[amino(aryl)-methylidene]-1,3-dihydro-2H-indol-2-ones (2b-f), are formed exclusively. There exist only two exceptions (4-methoxy and 2-pyridinthioamide) in which the Eschenmoser coupling reaction always takes place giving 2a and 2g. Also N-methylation of the starting 3-bromooxindole completely prevents formation of thiazoles. The prepared thiazoles 3b-f are unstable in solution and they undergo slow ring transformation to 2b-f. The rate limiting step of this rearrangement involves cleavage of an intermediary thiirane ring, which is slowed down by electron-withdrawing substituents on the thioamide (ρ = ?1.15).     

α-Ureidoalkylation of 1,3-bis(hydroxymethyl)-imidazolidin-2-one

The α-ureidoalkylation of imidazolidine-2,4-dione, urea, carboxylic acid amides, and sulfonamides has been studied using 1,3-bis(hydroxymethyl)-imidazolidin-2-one as ureidoalkylating agent. Methods have been developed for the synthesis of 1,3-bis(2,4-dioxoimidazolidin-1-ylmethyl)-, 1,3-bis(acetylaminomethyl)-, 1,3-bis(benzoylaminomethyl)-, 1,3-bis(phenylsulfonylaminomethyl)-, and 1,3-bis(p-toluenesulfonylaminomethyl)imidazolidin-2-ones. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1655–1659, November, 2007.     

2-Amino-5,5-bis(hydroxymethyl)-1,3-thiazol-4(5H)-one and its spirodioxane compounds in the Mannich reaction

It was found that the aminomethylation of 2-amino-5,5-bis(hydroxymethyl)-1,3-thiazol-4(5H)-one and its spiro analogs using primary amines is accompanied by cyclization at the amidine fragment of the molecule with annelation of a tetrahydrotriazine ring. When using secondary amines the aminomethylation occurs at the exocyclic nitrogen atom. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1252–1260, August, 2006.     

An electron density study on cis-1-(2-hydroxymethyl-cyclopentenyl)uracils

A topological charge electron density analysis using the Atoms in Molecules (AIM) theory on B3LYP/6-31++G**//B3LYP/6-31G* charge densities was performed for the series of the five cis-1-(2-hydroxymethyl-Δⁿ-cyclopentenyl))uraciles (n=1-5). These compounds are carbocyclic analogues of nucleosides that belong to an important class of antiviral or antitumoral compounds where the hydroxymethyl group and the heterocyclic base are bonded to adjacent carbons of a cyclopentene ring. The change of position of the double bond within the cyclopentene ring does not significantly affect the electron distribution of the base (that always carries a substantial negative charge), but alters the orientation of the base and the hydroxymethyl group (3-, and 4-cyclopentenyl derivarives being the exception as they present very similar conformations).     

Synthesis and crystal structure of (4S,5R)-2-[2-(hydroxyethyl)imino]-3,4-dimethyl-5-phenyl-1,3-thiazolidine

Acid hydrolysis of l-N-[N′-(2-vinyloxy)ethylcarbamothioyl]ephedrine was studied. The synthesized (4S,5R)-2-[2-(hydroxyethyl)imino]-3,4-dimethyl-5-phenyl-1,3-thiazolidine was studied by means of X-ray diffraction.     

Synthesis of conjugated (1E,3E)- and (1Z,3Z)-1,4-di(n-pyridyl) (or n-quinolyl)-1,3-butadienes from n-(2′-chloroethenyl)pyridine (or quinoline)

The homocoupling reaction between the conjugated n-(2-chloroethenyl)pyridine; n, 2-, 3- and 4- (or quinoline; n, 2- and 4-) mediated by zero-valent nickel complexes at room temperature affords to the corresponding 1,4-diaryl-1,3-butadiene, always as the 1E,3E stereoisomer. The yield in 1,4-diaryl-1,3-butadiene increases with the nickel catalyst and hence, the active zero-valent nickel catalyst is not regenerated during the homocoupling reaction.The stereospecific synthesis of (1Z,3Z)-1,4-di(4′-pyridyl)-1,3-butadiene stereoisomer was efficiently carried out by partial hydrogenation of the appropriate 1,4-di(4′-pyridyl)-1,3-butadiyne.     

New π-electron donors: Ethanediylidene-2,2′-bis(1,3-diselenole) and ethanediylidene-2-(1,3-dithiole)-2′-(1,3-diselenole)

This communication describes synthesis and electrochemical properties of new type of π-donors containing 1,3-diselenole ring, ethanediylidene-2,2′-bis(1,3-diselenole)(1a) and ethanediylidene-2-(1,3-dithiole)-2′-(1,3-diselenole)(2a). The conductivities of the charge-transfer complexes of these donors with tetracyanoquinodimethane (TCNQ) are also demonstrated.     

新型含2-取代-1,3-噻唑烷和噻唑环的亚胺类化合物的合成及生物活性

通过4-[(2-氰基亚胺基-1,3-噻唑烷-3-基)甲基]-2-氨基噻唑与取代苯甲醛的缩合反应, 合成了14个新型含2-取代- 1,3-噻唑烷和噻唑环的亚胺类化合物5. 所有化合物的结构均经1H NMR和元素分析确证, 并通过X射线单晶衍射分析测定了化合物5a的晶体结构. 初步生物活性试验结果表明, 部分目标化合物具有一定的杀菌活性和植物生长调节活性.     

Synthesis and properties of z-1,3-bis-(aryl)-4-bromo-2-buten-1-ones

Bromination of 1,3-bis(aryl)-2-buten-1-ones by N-bromosuccinimide in anhydrous carbon tetrachloride gives Z-1,3-bis(aryl)-4-bromo-2-buten-1-ones. The effect of the nature of substituent in the benzene ring on the course of a reaction with nucleophiles has been studied. Heating an alcohol solution of these ketones (Ar = 4-MeOC₆H₄, 4-ClC₆H₄) in the presence of acid or in the presence of base (Ar = Ph) gave 2,4-bis(aryl)furans. Treatment of 1,3-bis(aryl)-4-bromo-2-buten-1-ones with thioacetamide gave 2,4-bis(aryl)thiophenes. The oxidation of the halo-substituted dypnones with H₂O₂/NaOH gave (3-bromomethyl-3-aryl-2-oxiranyl)(aryl)methanones. The reaction of halo-substituted dypnones with aryl hydrazines gave 1,3,5-triaryl-1,6-dihydropyridazines or 1,3,5-triarylpyridazinium bromides depending on the structure of the reagents.     

Methanol facilitated synthesis of 7-methoxy-2-thioxo-2,3-dihydro-1H-1,3-diazepin-4(7H)-ones from nitroallylic acetates and thiourea

A novel efficient strategy for the synthesis of rare 7-methoxy-2-thioxo-2,3-dihydro-1H-1,3-diazepin-4(7H)-ones is described. Methanol, solvent for this one-step reaction, participated in this seven-membered ring closure reaction between nitroallylic acetates and thiourea. The thiourea itself also served as a base in this reaction. A possible mechanism for the reaction is proposed.     

Synthesis and structure of 1,3-dialkyl-4-(sulfonylimino)imidazolidin-2-ones

The reactions of 1,3-dialkyl-4,5-dihydroxyimidazolidin-2-ones with alkyl sulfamides have been studied and previously undescribed 1,3-dialkyl-4-(alkylaminosulfonylimino)imidazolidin-2-ones have been obtained. The structure of 1,3-dimethyl-4-(benzenesulfonylimino)imidazolidin-2-one was investigated by X-ray structural analysis. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1159–1166, August, 2007.     

Acetals and ethers,XVII. One- or two-step syntheses of 2-(2-alkoxyethyl)-1,3-dioxacyclanes

2-(2-Alkoxyethyl)-1,3-dioxanes (1) were prepared by ap-toluenesulfonic acid-catalyzed, one-step reaction of propenal with a mixture of aliphatic alcohol and trimethylene glycol in good yields. The transacetalization reaction of 1,1,3-trialkoxypropanes (3) with ethylene glycol or propylene-(1,2)glycol afforded good yields of pure 2-(2-alkoxyethyl)-1,3-dioxolanes (5 or6), respectively. This reaction proceeds through an intermediate 1,3-dialkoxy-1-(2-hydroxyalkoxy)-propane.

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Ein- oder Zweistufensynthese von 2-(2-Alkoxyethyl)-1,3-dioxacyclanen

Zusammenfassung In der durchp-Toluolsulfonsäure — katalysierten, direkten Reaktion von Propenal mit einem Gemisch von aliphatischem Alkohol und Trimethylenglykol wurden die entsprechenden 2-(2-Alkoxyethyl)-1,3-dioxane (1) in guten Ausbeuten erhalten. Die Umacetalisierung von 1,1,3-Trialkoxypropanen (3) mit Ethylenglykol oder 1,2-Propylenglykol lieferte 2-(2-Alkoxyethyl)-1,3-dioxolane (5 oder6) in guten Ausbeuten. Die Umacetalisierungsreaktion von 1,1,3-Trialkoxypropanen verläuft über 1,3-Dialkoxy-1-(2-hydroxyalkoxy)-propane als Zwischenprodukte.

     

Cationic polymerizations of substituted 2-methylene-1,3-dioxocyclic acetals, 2-methylene-1,3-dithiolane and copolymerization of 2-methylene-1,3-dithiolane with 4-(t-butyl)-2-methylene-1,3-dioxolane1

Carbon black-supported sulfuric acid or BF₃·Et₂O-initiated polymerizations of 2-methylene-4,4,5,5-tetramethyl-1,3-dioxolane (1), 2-methylene-4-phenyl-1,3-dioxolane (2), and 2-methylene-4-isopropyl-5,5-dimethyl-1,3-dioxane (3) were performed. 1,2-Vinyl addition homopolymers of 1–3 were produced using carbon black-supported H₂SO₄ initiation at temperatures from 0°C to 60°C whereas both ring-opened and 1,2-vinyl structural units were present in the polymers using BF₃·Et₂O as an initiator. Cationic polymerizations of 2-methylene-1,3-dithiolane (4) and copolymerization of 4 with 2-methylene-4-(t-butyl)-1,3-dioxolane (5) were initiated with either carbon black-sulfuric acid or BF₃·Et₂O. Insoluble 1,2-vinyl addition homopolymers of 4 were obtained upon initiation with the supported acid or BF₃·Et₂O. A soluble copolymer of 2-methylene-1,3-dithiolane (4) and 4-(t-butyl)-2-methylene-1,3-dioxolane (5) was obtained upon BF₃·Et₂O initiation. This copolymer is composed of three structural units: a ring-opened dithioester unit, a 1,2-vinyl-polymerized 1,3-dithiolane unit, and a 1,2-vinyl polymerized 4-(t-butyl)-1,3-dioxolane unit. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2823–2840, 1999     

Determination of molybdenum(VI) by differential pulse polarographic technique using 4-(2-hydroxy phenyl ethaminodiol), benzene-1,3-diol(4-2-HPEDB-1,3,D)

A novel analytical reagent 4-(2-hydroxy phenyl ethaminodiol), benzene-1,3-diol(4-2-HPEDB-1,3,D) was synthesized for the determination of molybdenum(VI). The present paper reveals the detailed study of electroanalytical behaviour for [Mo-(4-2-HPEDB-1,3,D)] complex under optimized conditions. The peak obtained for [Mo-(4-2-HPEDB-1,3,D)] prevent the interference of foreign ions which shows the sensitivity of the proposed method. The linearity was maintained at the concentration range of 0.5–200 μg/mL at pH 4.5 with correlation factor 0.9997. The present method was successfully applied for the analysis of molybdenum(VI) in biological fluids and plant material. The results obtained from the proposed method show good agreement with reference method.     

Synthesis and isomerization reaction of 2-(benzoxazol-2-yl)-1,3-tropolones

An acid-catalyzed reaction of 2-methylbenzoxazole with 3,4,5,6-tetrachloro-1,2-benzoquinone leads to 2-(benzoxazol-2-yl)-5,6,7-trichloro-1,3-tropolone and 2-(benzoxazol-2-yl)-4,5,6,7-tetrachloro-1,3-tropolone. 1,3-Tropolones upon reflux in ethyl alcohol undergo the rearrangement resulted in the seven-membered ring contraction to form ethyl 2-(benzoxazol-2-yl)-5,6-dichloro-3-hydroxybenzoate and ethyl 2-(benzoxazol-2-yl)-4,5,6-trichloro-3-hydroxybenzoate. The molecular structure of the latter was established by X-ray diffraction analysis.     

Synthesis and 13C NMR spectra of cis- and trans-{2-(haloaryl)-2-[(1H-imidazol)-1-yl]methyl]}-1,3-dioxolane-4-methanols

Syntheses and ¹³C nmr spectra of a number of cis and trans 2-(haloaryl)-2-[(1H-imidazol-1-yl)rnethyl]-4-(hydroxymethyl)-1,3-dioxolanes are described. The haloaryl groups are 2,4-dichloro, 2,4-difluoro-, 4-chloro-and 4-bromophenyl. In these series, some of the cis compounds become available through crystalline bromo benzoates 5 . Separations of some trans isomers are achieved through fractional crystallizations of imidazolyl benzoate nitrates 6 . Stereochemical assignments are based primarily on one major ¹³C chemical shift difference, namely that of C-4 of the 1,3-dioxolane ring, the chemical shift of the trans isomers being 1.0-2.5 ppm downfield from that of the cis isomers.