One-pot synthesis of bis (phenylimino dihydro thiazolyl-2H-chromene) derivatives

A novel series of bis (phenylimino dihydro thiazolyl-2H-chromene) derivatives have been synthesized through an efficient one-pot multicomponent approach involving different substituted of 3-(2-bromoacetyl)-2H-chromen-2-ones, phenyl isothiocyanates and para-phenylenediamine in presence of dimethylformamide solvent. The target compounds were obtained in a shorter reaction time through simple reaction work up with good yields. All the synthesized products were characterized by their spectral and analytical data like IR, ¹H NMR, ¹³C NMR, Roesy, and mass spectral data.     

Facile one-pot,three-component synthesis of novel bis(heterocycles) incorporating thieno[2,3-b]thiophenes via Michael addition reaction

A synthesis of novel series of bis(2-amino-3-cyano-4H-chromene), bis(2-amino-3-cyanopyrano[3,2-c]chromene), bis(6-amino-5-cyano-1,4-dihydropyrano[2,3-c]pyrazole), and bis(2,7-diamino-3,4,6-tricyanopyrazolo[1,5-a]pyridine) derivatives linked to thieno[2,3-b]thiophene core via ether or ester linkages was reported. The formation of the target compounds presumably proceeds through a three component reaction of the appropriate bis(aldehyde) with 2 M of each of malononitrile and the corresponding active methylene compounds namely; dimedone, 4-hydroxycoumarine, 5-methyl-2,4-dihydro-3H-pyrazol-3-one, or cyanomethylpyrazole in dioxane at reflux in the presence of piperdine as a basic catalyst. The chemical structures of the new compounds were elucidated by several spectral tools.     

Piperazine-mediated tandem synthesis of bis(thieno[2,3-b]pyridines): Versatile precursors for related fused [1,2,4]triazolo[4,3-a]pyrimidines

In this study, we discuss the utility of bis(cyanoacetamides) as versatile precursors to the piperazine-mediated synthesis of a wide spectrum of bis(thieno[2,3-b]pyridine) derivatives, linked to aliphatic spacers via thioethers. The proposed tandem protocol involved the reaction of bis(cyanoacetamides) with two equivalents of the appropriate cinnamonitriles in dioxane in the presence of six equivalents of piperazine at reflux for 4 hours. Then, two equivalents of the appropriate halogen-containing reagents were added and the reaction was heated at reflux for further 3 hours. The bis(thieno[2,3-b]pyridines) were taken as a key intermediates to new bis(4-oxopyrido[3′,2′:4,5]thieno[3,2-d]pyrimidines). The above derivatives were reacted with the appropriate hydrazonyl chloride derivatives in dioxane in the presence of triethylamine to yield the corresponding bis([1,2,4]triazoles) with a related fused pyridothienopyrimidine moiety. The new structures were elucidated by IR, NMR spectral data, as well as elemental analyses.     

Microwave‐Assisted Synthesis of Novel Bis(thiazoles) Incorporating Piperazine Moiety

Novel bis(hydrazinecarbothioamide) was prepared by the reaction of 1,4‐bis[(3‐formyl‐4‐hydroxyphenyl)methyl]piperazine with thiosemicarbazide. The bis(hydrazinecarbothioamide) was used as a building block for construction of a novel bis(thiazolyl)piperazines via its cyclocondensation with a series of each of α‐halocarbonyl compounds and hydrazonoyl halides in dimethylformamide in the presence of triethylamine as a catalyst under microwave irradiation. The structure of the newly bis(thiazolyl)piperazine derivatives is elucidated via the spectral data as well as elemental analyses.     

Preparation of samarimm(ii) sulfide by the reaction of samarium(II) bis[bis(trimethylsilyl)amide] with hydrogen sulfide

X-ray amorphous samarium(II) sulfide was prepared by the reaction of H₂S with samarium(II) bis[bis(trimethylsilyl)amide] (1) in THF at 10^–2 Torr. Compound1 was prepared by two methods: 1) the reaction of SmI₂ with lithium bis(trimethylsilyl)amide and 2) the reaction of samarium naphthalide with bis(trimethylsilyl)amine. SmS was transformed to the polycrystalline state with the lattice parametera = 5.92 Å by annealing at 400–500 °C.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 241–243, February, 1995.     

Reactions of Cyanomethanesulfonamides with Aldehydes and Synthesis of 2-Benzyl-2,3-dihydrobenzopyrano[3,2-e] [1,2,4]thiadiazine 1,1-Dioxides

Summary.  Reactions of cyanomethanesulfonamides with aromatic aldehydes in the presence of AcOH and piperidine produced the addition products, the 1-cyano-2-arylethenesulfonamides, whereas reactions with benzonitrile yielded the 2-amino-1-cyano-2-phenylethenesulfonamides only when done in THF with BuLi. No addition products were isolated from the analogue reactions with 2-hydroxybenzaldehyde (salicylaldehyde). Instead, we obtained 2-imino-2H-chromene-3-sulfonamides with good to excellent yields. These 2H-chromene derivatives allowed a number of transformations, from which the reactions with orthoformates opened an approach to the hitherto unknown benzopyrano[3,2-e] [1,2,4]thiadiazine ring system.     

Reactions of Cyanomethanesulfonamides with Aldehydes and Synthesis of 2-Benzyl-2,3-dihydrobenzopyrano[3,2-e] [1,2,4]thiadiazine 1,1-Dioxides

Reactions of cyanomethanesulfonamides with aromatic aldehydes in the presence of AcOH and piperidine produced the addition products, the 1-cyano-2-arylethenesulfonamides, whereas reactions with benzonitrile yielded the 2-amino-1-cyano-2-phenylethenesulfonamides only when done in THF with BuLi. No addition products were isolated from the analogue reactions with 2-hydroxybenzaldehyde (salicylaldehyde). Instead, we obtained 2-imino-2H-chromene-3-sulfonamides with good to excellent yields. These 2H-chromene derivatives allowed a number of transformations, from which the reactions with orthoformates opened an approach to the hitherto unknown benzopyrano[3,2-e] [1,2,4]thiadiazine ring system.     

A triangular palladium(II) supramolecular coordination complex based on 1,4‐bis(1H‐imidazol‐1‐yl)benzene and (2,2′‐bipyridyl)palladium(II) nitrate: synthesis and crystal structure

The self‐assembly of ditopic bis(1H‐imidazol‐1‐yl)benzene ligands ( L ^H) and the complex (2,2′‐bipyridyl‐κ²N,N′)bis(nitrato‐κO)palladium(II) affords the supramolecular coordination complex tris[μ‐bis(1H‐imidazol‐1‐yl)benzene‐κ²N³:N^3′]‐triangulo‐tris[(2,2′‐bipyridyl‐κ²N,N′)palladium(II)] hexakis(hexafluoridophosphate) acetonitrile heptasolvate, [Pd₃(C₁₀H₈N₂)₃(C₁₂H₁₀N₄)₃](PF₆)₆·7CH₃CN, 2 . The structure of 2 was characterized in acetonitrile‐d₃ by ¹H/¹³C NMR spectroscopy and a DOSY experiment. The trimeric nature of supramolecular coordination complex 2 in solution was ascertained by cold spray ionization mass spectrometry (CSI–MS) and confirmed in the solid state by X‐ray structure analysis. The asymmetric unit of 2 comprises the trimetallic Pd complex, six PF₆^? counter‐ions and seven acetonitrile solvent molecules. Moreover, there is one cavity within the unit cell which could contain diethyl ether solvent molecules, as suggested by the crystallization process. The packing is stabilized by weak inter‐ and intramolecular C—H…N and C—H…F interactions. Interestingly, the crystal structure displays two distinct conformations for the L ^H ligand (i.e. syn and anti), with an all‐syn‐[Pd] coordination mode. This result is in contrast to the solution behaviour, where multiple structures with syn/anti‐ L ^H and syn/anti‐[Pd] are a priori possible and expected to be in rapid equilibrium.     

From Levulinic Acid to Biheterocycles: Synthesis of 1-[(5-Hydroxy-5-trifluoromethyl-3-substituted-4,5-dihydro-1H-pyrazol-1-yl)-3-(5-trifluoromethyl-1H-pyrazol-3-yl)propan-1-ones

We develop an efficient method to synthesize novel propionyl-spaced bisheterocyclic compounds. It entails cyclocondensation of 3-(5-trifluoromethyl-1H-pyrazol-3-yl)propanoyl hydrazide obtained from levulinic acid, with 1,1,1-trifluoro-4-methoxy-3-alken-2-ones proceeding regiospecifically to 1-[(5-trifluoromethyl-5-hydroxy-3-substituted-4,5-dihydro-1H-pyrazol-1-yl)-3-(5-trifluoromethyl-1H-pyrazol-3-yl)propan-1-one derivatives.     

(Diisopropylamido) bis (methylcyclopentadienyl) lanthanides as single-component initiators for polymerization of methyl methacrylate

It was first found that (diisopropylamido)bis(methylcyclopentadienyl)lanthanides (MeC₅H₄)₂LnN(i-Pr)₂(THF) (Ln = Yb ( 1 ), Er ( 2 ), Y ( 3 )) exhibit extremely high catalytic activity in the polymerization of methyl methacrylate. The reactions can be carried out over a quite broad range of polymerization temperatures from -78 to 40°C. The catalytic activity of the complexes increases with an increase of ionic radii of the metal elements, i.e. Y > Er > Yb. The results of GPC (gel permeation chromatography) indicate that the number-average molecular weights (M_n) of polymers obtained exceed 100 × 10³ and the molecular weight distribution (M_w/M_n) becomes broad with the increase of temperature. Furthermore highly syndiotactic PMMA (87.7%) can be obtained by lowering the reaction temperature to −78°C. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1593–1597, 1998     

Synthesis of novel scaffolds based on thiazole or triazolothiadiazine linked to benzofuran or benzo[d]thiazole moieties as new hybrid molecules

Abstract

A synthesis of novel hybrid molecules containing thiazole or bis(thiazoles) each bearing benzofuran and/or benzo[d]thiazole moieties by the reaction of the appropriate thioamide derivatives with the corresponding bis-bromoacetyl derivatives is reported. Mono- and bis(triazolothiadiazine) derivatives based on benzofuran or benzo[d]thiazole moieties were also synthesized in good yields by the reaction of the appropriate bis(bromoacetyl) derivatives with each of 4-amino-5-mercapto-1,2,4-triazoles and their corresponding bis-derivatives.     

Anti‐corrosion properties of bis(benzimidazole) derivatives for N80 steel in H2S solution

In this work, we systematically investigated the effect of four bis(benzimidazole) derivatives containing different heteroatoms in molecular structures on inhibiting corrosion of N80 steel in 0.5 mmol·l^?1 H₂S solution by potentiodynamic polarization, electrochemical impedance spectroscopy and metallographic microscope. The results showed that within the range of 0.1–1.0 mmol·l^?1, the adsorption of bis(benzimidazole) derivatives on N80 steel surface was found to follow Langmuir adsorption isotherm. Meanwhile, stable adsorbing monolayer between inhibitors and the metal surface was formed, which was confirmed by thermodynamic adsorption parameters (K_ads, ). This series of bis(benzimidazole) derivatives exhibited obvious corrosion inhibitory properties for N80 steel. Moreover, they could both slow down the anodic dissolution of iron and the cathodic reduction reaction as mixed type corrosion inhibitors. The optimal inhibition efficiency was obtained for 1,3‐bis(benzimidazl‐2‐yl)‐2‐thiapropane (BBMS). Hopefully, this series of inhibitors might find applications in anti‐corrosion and many other areas. Copyright © 2012 John Wiley & Sons, Ltd.     

Formation of arynezirconocenes from substituted diaryl bis (t-butylcyclopentadienyl) zirconium: application to the synthesis of new functionalized ortho-dichalcogenobenzene compounds

The para-substituted diphenylzirconocenes [(t-BuCp)₂Zr(p-C₆H₄R)₂; R = Br, NMe₂] (A) were easily obtained from the reaction of the appropriate organolithium reagent with bis(t-butylcyclopentadienyl)zirconium dichloride. Elimination of bromobenzene or N,N-dimethylaminobenzene from A by slight heating led to arynezirconocenes into which were inserted two equivalents of elementary chalcogens. As a result dichalcogenated zirconacycles [(t-BuCp)₂ZrY₂C₆H₃R; Y = S, Se] (B) were obtained. Complexes B constitute useful potential synthons in organic synthesis and a large family of new functionalized dichalcogenated benzenic compounds was prepared by reacting electrophiles. The structure of complexes B as well as related benzenic derivatives has been confirmed by microanalysis, ¹H NMR and mass spectrometry.     

Uncatalyzed,One-pot Synthesis of 3,3'-(Benzylene)bis(4-hydroxy-2H-chromen-2-one)Derivatives under Thermal Solvent-free Conditions

A series of 3,3′‐(benzylene)bis(4‐hydroxy‐2H‐chromen‐2‐one) derivatives have been synthesized from condensation reactions of 4‐hydroxycoumarin with benzaldehydes under thermal solvent‐free conditions. This environmentally friendly synthesis is uncatalyzed and affords the desired products in excellent yields.     

Synthesis and properties of mono- and bis[2-(dimethylaminomethyl)]cymantrenyl derivatives of ytterbium

The reaction of [2-(dimethylaminomethyl)]cymantrenyl]lithium with ytterbium diiodide affords [2-(dimethylaminomethyl)cymantrenyl]ytterbium iodide or bis[2-(dimethylaminomethyl)cymantrenyl]ytterbium depending on the ratio of the starting reactants. Reactions of these complexes with a series of electrophiles (H₂O, Me₃SiCl, MeCOCl, HgCl₂, PhCOCl) were studied and the corresponding derivatives of cymantrene were prepared in high yields.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No.3, pp. 531–533, March, 1994.     

Tetra‐ and hexahydrates of bis(adeninium) zoledronate

The present paper reports the structures of bis(adeninium) zoledronate tetrahydrate {systematic name: bis(6‐amino‐7H‐purin‐1‐ium) hydrogen [1‐hydroxy‐2‐(1H‐imidazol‐3‐ium‐1‐yl)‐1‐phosphonatoethyl]phosphonate tetrahydrate}, 2C₅H₆N₅⁺·C₅H₈N₂O₇P₂²⁻·4H₂O, (I), and bis(adeninium) zoledronate hexahydrate {systematic name: a 1:1 cocrystal of bis(6‐amino‐7H‐purin‐1‐ium) hydrogen [1‐hydroxy‐2‐(1H‐imidazol‐3‐ium‐1‐yl)‐1‐phosphonatoethyl]phosphonate hexahydrate and 6‐amino‐7H‐purin‐1‐ium 6‐amino‐7H‐purine dihydrogen [1‐hydroxy‐2‐(1H‐imidazol‐3‐ium‐1‐yl)ethane‐1,1‐diyl]diphosphonate hexahydrate}, 2C₅H₆N₅⁺·C₅H₈N₂O₇P₂²⁻·6H₂O, (II). One of the adenine molecules and one of the phosphonate groups of the zoledronate anion of (II) are protonated on a 50% basis. The zoledronate group displays its usual zwitterionic character, with a protonated imidazole ring; however, the ionization state of the phosphonate groups of the anion for (I) and (II) are different. In (I), the anion has both singly and doubly deprotonated phosphonate groups, while in (II), it has one singly deprotonated phosphonate group and a partially deprotonated phosphonate group. In (I), the cations form an R₂²(10) base pair, while in (II), they form R₂²(8) and R₂²(10) base pairs. Two water molecules in (I) and five water molecules in (II) are involved in water–water interactions. The presence of an additional two water molecules in the structure of (II) might influence the different ionization state of the anion as well as the different packing mode compared to (I).     

Guanidine hydrochloride catalyzed efficient one-pot pseudo five-component synthesis of 4,4′-(arylmethylene)bis(1H-pyrazol-5-ols) in water

The present methodology describes an efficient, environmentally friendly and simple protocol for the synthesis of some 4,4′-(arylmethylene)bis(1H-pyrazol-5-ol) derivatives through a one-pot pseudo-five-component reaction of hydrazine hydrate/phenyl hydrazine, ethyl acetoacetate, and various aromatic aldehydes catalyzed by guanidine hydrochloride. This condensation reaction was performed by tandem Knoevenagel–Michael reaction in water under refluxing conditions giving the title compounds in 82–92% yields. Atom economy, simple operation, easy work-up, using inexpensive organocatalyst, high yields in short times, clean transformation, and environmentally benign are some of the important features of this new protocol.     

Synthesis, characterization and hydrolytic behavior of new bis(2-pyridylthio)acetate ligand and related organotin(IV) complexes

The new sodium bis(2-pyridylthio)acetate ligand, Na[(pyS)₂CHCO₂], has been prepared in ethanol solution using 2-mercaptopyridine, dibromoacetic acid and NaOH. New mono- and di-organotin(IV) derivatives containing the anionic bis(2-pyridylthio)acetate have been synthesized from reaction between SnR_nCl_4−n (R = Me, Ph and ⁿBu, n = 1-2) acceptors and Na[(pyS)₂CHCO₂]. Mono-nuclear complexes of the type {[(pyS)₂CHCO₂]R_nSnCl_4−n−1} have been obtained and characterized by elemental analyses, FT-IR, ESI-MS, multinuclear (¹H and ¹¹⁹Sn) NMR spectral data and X-ray crystallography. ESI-MS spectra of methanol solution of the complexes show the existence of hydrolysed species. Attempts to crystallize the dimethyltin(IV) derivative (3), from acetonitrile solution yield the dimeric dicarboxylatotetramethyldistannoxane (8), which was characterized by single crystal diffraction analysis.     

Bis(trimethylsilyl)amide und -methanide des Yttriums — Molekülstrukturen von Tris(diethylether-O)lithium-(μ-chloro)-tris[bis(trimethylsilyl) methyl]yttriat,solvensfreiem Yttrium-tris[bis(trimethylsilyl)amid] sowie dem Bis(benzonitril)-Komplex

Bis(trimethylsilyl)amides and -methanides of Yttrium — Molecular Structures of Tris(diethylether-O)lithium-(μ-chloro)-tris[bis(trimethylsilyl)methyl]yttriate, solvent-free Yttrium Tris[bis(trimethylsilyl)amide] as well as the Bis(benzonitrile) Complex The reaction of yttrium(III) chloride with the three-fold molar amount of LiE(SiMe₃)₂ (E = N, CH) yields the corresponding yttrium derivatives. Yttrium tris-[bis(trimethylsilyl)amide] crystallizes in the space group P3 1c with a = 1 636,3(2), c = 849,3(2) pm, Z = 2. The yttrium atom is surrounded trigonal pyramidal by three nitrogen atoms with Y? N-bond lengths of 222 pm. Benzene molecules are incorporated parallel to the c-axes. The compound with E = CH crystallizes as a (Et₂O)₃LiCl-adduct in the monoclinic space group P2₁/n with a = 1 111,8(2), b = 1 865,2(6), c = 2 598,3(9) pm, β = 97,41(3)° and Z = 4. The reaction of yttrium tris[bis(trimethylsilyl)amide] with benzonitrile yields the bis(benzonitrile) complex, which crystallizes in the triclinic space group P1 with a = 1 173,7(2), b = 1 210,3(2), c = 1 912,4(3) pm, α = 94,37(1), β = 103,39(1), γ = 117,24(1)° and Z = 2. The amido ligands are in equatorial, the benzonitrile molecules in axial positions.     

Synthesis and characterization of sodium bis(trimethylstannyl) amide and bis(trimethylsilyl) bis(trimethylstannyl) -phospha-tetrazene

Sodium bis(trimethylstannyl)amide NaN(SnMe₃)₂, isolated by the reaction of trimethylstannyldiethylamine with sodium amide, reacts with tris(trimethylsilyl)hydrazino—dichloro-phosphine to form bis(trimethylsilyl)bis(trimethylstannyl)-2-phospha-2-tetrazene, (Me₃Si)₂N-N=P-N(SnMe₃)₂. Both the molecules have been isolated and characterized.