Heterocyclic compounds from 2-(alkoxycarbonylcyanomethylene)-1,3-dioxolanes

2-(Alkoxycarbonylcyanomethylene)-1,3-dioxolanes reacted with hydrazines and hydroxylamine to yield 1-substituted 4-alkoxycarbonyl-5-amino-3-(2′-hydroxyethoxy)pyrazoles and 4-alkoxycarbonyl-5-amino-3-(2′-hydroxyethoxy)isoxazoles respectively. With guanidine and benzamidine 2-substituted (R = NH₂, C₆H₅) 5-cyano-6-(2′-hydroxyethoxy)pyrimidin-4-ones were obtained. Reaction of 2-(cyanomethoxycarbonylmethylene)-1,3-dioxolane with 1,3-diaminopropane afforded 2-(cyanomethoxycarbonylmethylene)-1,3-hexahydro-pyrimidine whereas treatment of the same compound with 4,5-dimethyl-1,2-phenylenediamine gave 2-(cyanomethoxycarbonylmethylene)-5,6-benzimidazoline. The structures of pyrazoles and pyrimidones were assigned on the basis of ¹H-{¹H} and ¹³C-{¹H}-nOe experiments.     

1,3-二(乙氧基甲基)-5-N,N-二甲氨基-6-甲基尿嘧啶的合成

报道了1,3-二(乙氧基甲基)-5-N,N-二甲氨基-6-甲基尿嘧啶方便、高产率的合成方法. 以6-甲基尿嘧啶(1)为起始物, 经硝化、嘧啶N¹,N ³-烷基化、还原及氨基甲基化, 首次高产率合成了1,3-二(乙氧基甲基)-5- N,N -二甲氨基-6-甲基尿嘧啶(5), 并对其化学结构进行了表征.     

The One Step Synthesis of 2-(2-Bromo-5- methoxyphenyl)-5-(3-arylidene)-1,3-thiazolo[3,2-b]- 1,2,4-triazol-6-(5H)-ones and the Evaluation of the Anticonvulsant Activity

A smooth one-step synthesis of 2-(2-bromo-5-methoxyphenyl)-5-(3-arylidene)-1,3-thiazolo[3,2-b]-1,2,4-triazol-6-(5H)-ones (4a–n) is described. The newly prepared compounds are characterized by analytical and IR, ¹ H NMR, ¹³ C NMR, and FABMS spectral analysis. A few compounds are screened for anticonvulsant activity. Compounds 4i and 4n exhibit promising anticonvulsant activity and are recommended for further studies.     

Synthesis of 3-[4-(1-Benzofuran-2-yl)-1,3-thiazol-2-yl]-2-(4-aryl)-1,3-thiazolidin-4-one Derivatives as Biological Agents

A protocol for the synthesis of 3-[4-(1-benzofuran-2-yl)-1,3-thiazol-2-yl]-2-(4-aryl)-1,3-thiazolidin-4-one derivatives (5a–e) has been developed from 1-(1-benzofuran-2-yl)-2-bromoethanone (2),which served as a key intermediate for the synthesis of the title compounds. The reaction of compound 2 with thiourea furnished 4-(1-benzofuran-2-yl)-1,3-thiazol-2-amine 3, which upon further reaction with various aromatic aldehydes, gave Schiff bases 4a–e. These Schiff bases, when treated with thioacetic acid in the presence of catalytic amount of anhydrous ZnCl₂, yielded thiazolidinone derivatives 5a–e. All the newly synthesized compounds have been characterized by analytical and spectral data and screened for their antimicrobial and analgesic activity.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

A spectroscopic study of 1,3-dimethyl-2-(trimethylstannyl)-1,3-diaza-2-boracycloakanes

The vibrational spectra of 1,3-dimethyl-2-(trimethylstannyl)-1,3-diaza-2-boracyclopentane and the corresponding diazacyclohexane derivatives as well as those of some other 1,3-diaza-2-boracycloalkanes have been recorded. Boron-nitrogen valence vibrations are observed in the 1500±10 cm^?1 frequency region and boron-tin stretching is assigned near 760 cm^?1. These data are discussed in conjunction with the ¹¹B and ¹H NMR spectra of the various heterocycles and the tin Mössbauer spectra of the two boron-tin species.     

2,3-Bis(diphenylphosphino)-1,3-butadien

2,3-Bis(diphenylphosphino)-1,3-butadiene A method for synthesis of the title compound is described, using the readily available 2,3-bis(diphenylphosphinoyl)-1,3-butadiene ( 1 ) as the starting material. For the protection of the diene system, 1 is first converted into the 1,4-dibromo- and 1,4-dichloro derivatives 2a and b , respectively, by addition of Br₂ or Cl₂, respectively. The structure of 2b has been determined by single-crystal X-ray diffraction. The molecule has a centrosymmetrical (E)-configuration. Reduction of the phosphinoyl groups by HSiCl₃(to give the bis(diphenylphosphino)compound 3), followed by removal of the Cl-atoms using Zn powder, affords the bis(diphenylphosphino)butadiene 4 . Compounds 3 and 4 give quaternary phosphonium salts 5 and 6 , respectively, on addition of CH₃OSO₂F or CH₃I. The sulfur analogue of 1 is formed on treatment of 4 with elemental sulfur.     

Synthesis and biological activity of novel 4- and 6-(1-alkyl/aryl-1H-benzimidazol-2-yl)benzene-1,3-diols

Abstract  

A one-pot synthesis of new biologically active 4- and 6-(1-alkyl/aryl-1H-benzimidazol-2-yl)benzene-1,3-diols has been developed. The compounds were obtained by the reaction of aryl-modified sulfinylbis[(2,4-dihydroxyphenyl)methanethione] with N-substituted benzene-1,2-diamines. Elemental analysis, IR, ¹H NMR, ¹³C NMR, and mass spectral data were used to elucidate their structures. The developed method offers short reaction times, easy and quick isolation of the products, and good yields. The antiproliferative properties of the synthesized compounds were investigated against a panel of human cancer cell lines. Some of the tested compounds showed significant cytotoxic activity.     

Synthesis and absolute configuration of two diastereoisomeric (1R,2S,3R)-and (1S,2S,3R)-2-amino-1-(2-furyl)-1,3-butandiols

The synthesis of (1R, 2S, 3R) and (1S, 2S, 3R)-2-(N-benzoylamino)-1-(2-furyl)-1, 3-butandiols (15) and (16) from D-threonine is described. The assignment of absolute configuration of the newly formed asymmetric center at C-1 was based on the ¹H-NMR spectra of O-isopropylidene derivatives 17 and 18.     

Über die Synthese von 1,3-Dihydro-3-(2-dimethylaminoäthyl)-1-(3-thienyl)-benzimidazol-2-onen

The synthesis of 1-(3-thienyl)-benzimidazol-2-ones (3 a and4), described in an earlier paper¹, has been further investigated. The Na-salt of3 a is converted to a benzimidazolone substituted in position 3 (3 b). Dehydrogenation of the thiophene nucleus of3 a with chloranil yields5 a, which undergoes substitution in position 3 with Cl(CH₂)₂N(CH₃)₂ to give5 b. Monochlorination of5 a yields5 c, the structure of which is confirmed by¹H-NMR-spectroscopy.5 d is obtained by reaction of the Na-salt of5 c with Cl(CH₂)₂N(CH₃)₂.      

Substituted N-(2-Hydroxyethyl)-1,3-thiazolidin-4-ones: Synthesis and Anticorrosive Properties

A one-pot procedure was developed for synthesis of N-(2-hydroxyethyl)-1,3-thiazolidin-4-ones in 64-68% yield by reactions of monoethanolamine with carbonyl compounds and mercaptoacetic acid. The synthesized compounds were characterized by IR and ¹H NMR spectra, and their anticorrosive properties were studied.     

无溶剂条件下合成2-[3-氧代-1,3-二(未)取代苯基丙基]-1,2,3,4-四氢萘-1-酮

以3,4-二氢-1-萘酮和查尔酮为原料, 在 K₂CO₃-NaOH 存在下, 无溶剂室温研磨反应, 方便地得到2-[3-氧代-1,3-二(未)取代苯基丙基]-1,2,3,4-四氢萘-1-酮. 该方法具有反应条件温和、操作简单和产率较高等优点, 并通过IR, ¹H NMR, 元素分析确定了产物的结构, 3b晶体结构通过X衍射测定.     

Synthesis of [2-(vinyloxy)ethyl]uracil and [2-(allyloxy)ethyl]uracil

A synthesis is reported for N¹-mono- and N¹,N³-disubstituted uracil derivatives containing a terminal carbon-carbon double bond in the side-chain. Alkylation of vinyl 2-chloroethyl ether by uracil potassium salts leads to a mixture of 1-[2-(vinyloxy)ethyl] and 1,3-di[2-(vinyloxy)ethyl] derivatives while treatment of 2,4-bis(trimethylsilyloxy)pyrimidines by vinyl 2-chloroethyl ether leads exclusively to N¹-monosubstituted products. Alkylation of cytosine by this chloroether gave 1-[2-(vinyloxy)ethyl]cytosine. The synthesis of 1-[2-(allyloxy)ethyl]uracil derivatives was carried out by treatment of uracil potassium salts by 1-(allyloxy)-2-(p-toluenesulfonyloxy)ethane.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 393–397, March, 1993.     

Thermolyse von Arylhalogenboranen; Synthese von 1,3-Dibora- und 1,3-Borasilaindanen

The thermolysis of the 2-silylated or borylated arylboranes (3a-g, or 9a,b) has been investigated. The synthesis of the unknown starting boranes succeeds upon treatment of the (o-(dichloroboryl)phenyl)trimethylsilane (3b) with trimethylalane (giving 3e), tetramethylstannane (giving 3f) or diisopropylamine (giving 3g) and upon trimethylation of the 1,2-bis(dichloroboryl)benzene (9a) with tetramethylstannane (giving 9b). In solution 3b,c, and 9a,b “dimerize” readily in a temperature range between 45 and 135°C with the liberation of halotrimethylsilanes or chloroboranes yielding the 9,10-dibora-9,10-dihydroanthracenes. The reaction mechanism is discussed. To force intramolecular reactions exclusively, flash vacuum pyrolyses (FVP) were performed at about 650°C. When pyrolyzing 3b elimination of hydrogen chloride occurs yielding 1,1-dimethyl-3-chloro-1-sila-3-boraindane (11). After pyrolysis of 11 at 750°C intramolecular, mutual migration of a chloro and a methyl group takes place. Possible rearrangement mechanisms are discussed and have been experimentally in investigated. Hydrogen chloride is the best leaving molecule in these pyrolyses. Extrusion of methanol (from (o-(dimethoxyboryl)phenyl)trimethylsilane (3d)) or methane (from 3e) gives the corresponding borasilaindanes only at 750°C and in lower yields. The synthesis of the very sensitive 1,3-dimethyl-1,3-diboraindane also succeeds by FVP (550°C) starting with 9b. The high-field shifts of the ²⁹Si and the ¹¹B NMR signals of the borasilaindanes compared to the chemical shifts of the corresponding parent bora- and silaindane systems are considered as evidence for a through-bond interaction between both hetero atoms.     

Metal Complexes of the Tetraethyl Ester of 4-(2-Hydroxyphenylamino)-1,3-butadiene-1,3-diphosphonic Acid and the Liquid Phase Oxidation of Cumene in their Presence

Abstract

The tetraethylester of 4-(2-hydroxy-phenylamino)-1,3-butadiene-1,3-diphosphonic acid 3 and its zinc and cobalt complexes (3-Zn, 3-Co) have been synthesized and their structures were determined by IR, ¹-NMR, ³¹P{¹H}-NMR and ¹³C-NMR spectral investigations. The affect of these compounds on the liquid phase oxidation of cumene is studied and compared with that of 2-aminophenol 2 and its metal complexes 2-M. It is found that the ligand 3 shows the strongest inhibiting effect, while 3-Co,3-Zn and 2-Co accelerate the oxidation process. The strong inhibiting effect of the ligand 3 is due to its possibility to react with cumeneperoxide radicals. The disappearance of inhibiting properties in the complexes 3-Zn and 3-Co shows that eleKtrophilic attack of cumeneperoxide radicals is directed to OH or NH groups of 3. Most probably the OH group is affected becouse a similar absence of inhibiting properties is inherent to the 2-Co. The presence of inhibiting properties of the 2-Zn as opposed to 2-Co could mean that this complex (2-Zn) has a more complicated, still unknown structure, possibly a polymeric one.     

Induced circular dichroism spectra of 2-(2,4,6-cycloheptatrien-1-ylidene)-4-cyclopentene-1,3-dione included inβ-cyclodextrin

The assignment of the absorption spectra of 2-(2,4,6-cycloheptatrien-1-ylidene)-4-cyclopentene-1,3-dione (1) is reported by measuring the induced circular dichroism spectra of the β-cyclodextrin complex with1. It is concluded from the signs of the induced circular dichroism bands that the first absorption band (17.1×10³–34.3×10³ cm^?1) is composed of three electronic transitions having perpendicular, parallel and perpendicular polarizations with respect to the long axis (z) of1. The second absorption band (34.3×10³–42.8×10³ cm^?1) is composed of two electronic transitions having parallel polarizations with respect to the long axis of1 and the third absorption band (42.8×10³–47.1×10³ cm^?1) has the transition dipole moment perpendicular to the long axis of1. Our experimental assignments are supported by CNDO/S CI calculations.     

Regioselective electroreduction of 6h-1,3-thiazines. Comparison with chemical reductions I - investigation of 2-phenyl-6H-1,3-thiazines

The electrochemical reduction of 2-phenyl-6H-1,3-thiazines carried out at a mercury cathode in acetate buffer + ethanol (1:1) has been studied : - In the case of compounds monoactivated at carbon 5 (R⁵ = CHO or COCH₃) either hydrodimers (resulting from coupling at C-2), 3,6-dihydro-2H-1,3-thiazines (reduction of the imine bond) or tetrahydrothiazines can be obtained. - Diactivated 6H-1,3- thiazines (R⁴ = CO₂Et, R⁵ = CHO or COCH₃) successively lead to 5,6-dihydro-4H-1,3-thiazines (reduction of the ethylenic bond) and tetrahydrothiazines. - The reduction of a 6H-1,3-thiazine bearing only one withdrawing group at carbon 4 gives rise to a ring opening. At the same time, the action of various chemical reducing agents has been examined : the reduction of the imine bond is performed using NaBH₃CN while NaBH₄ or LiAlH₄ leads to the reduction of the substituents on the heterocyole.     

1,3-Bis[2-(ethynyldimethylsilyl)vinyl]tetramethyldisiloxane and Macrocyclic Polyunsaturated Siloxanes on Its Basis

Hydrosilylation of diethynyldimethylsilane with tetramethyldisiloxane in the presence of chloroplatinic acid give rise to a mixture of three stereoisomers of 1,3-bis[2-(ethynyldimethylsilyl)vinyl]tetramethyldisiloxane: trans-trans, gem-trans, and gem-gem. Hydrolysis of chloro[2-(ethynyldimethylsilyl)vinyl]dimethylsilane provides the trans-trans isomer of 1,3-bis[2-(ethynyldimethylsilyl)vinyl]tetramethyldisiloxane exclusively. Reactions of an organomagnesium derivative of the disiloxane with dichlorodiorganylsilanes allowed synthesis of novel polyunsaturated macrocyclic siloxanes. The ¹H, ¹³C, and ²⁹Si NMR spectra of the products were studied.     

Synthesis of 2-chloro-5-hydroxynicotinonitrile: The required intermediate in the total synthesis of a hydroxylated metabolite of (S)-2-(3-t-butylamino-2-hydroxypropoxy)-3-cyanopyridine

A convenient method for the synthesis of 2-chloro-5-hydroxynicotinonitrile ( 10 ) via 5-amino-2-chloro-3-methylpyridine ( 3 ) is described. Subsequent conversions provided the basic metabolite 2 of (S)-2-(3-t-butylamino-2-hydroxypropoxy)-3-cyanopyridine ( 1 ). ¹³C Nmr data is also presented to characterize 2-chloro-5-fluoro-3-methylpyridine ( 5 ), a by-product in the Schiemann reaction having unexpected ¹H and ¹⁹F nmr spectra.     

Molecular and crystal structure of 4-trifluoro-2-[2-(4-fluorophenyl)hydrazine-1-ylidene]-1-(thiophen -2-yl)butane-1,3-dione

Single crystal X-ray diffraction is used to determine the crystal and molecular structure of 4-trifluoro-2-[2-(4-fluorophenyl)hydrazine-1-ylidene]-1-(thiophen-2-yl)butane-1,3-dione. Crystallographic data for C₁₄H₈F₄N₂O₂S are as follows: a = 8.2723(6) ?, b = 9.3009(7) ?, c = 9.9895(7) ?; α = 79.224(2)°, β = 75.851(2)°, γ = 72.337(2)°. Triclinic crystal system, P-1 space group, d _x = 1.622 g/cm³, V = 704.83(9) ?³, μ = 0.286 mm⁻¹, crystal size 0.30×0.20×0.20 mm, R1 = 0.0891, wR2 = 0.1989.