Calix[4]arenes bearing α‐amino‐ or α‐hydroxyphosphonic acid fragments at the upper rim

By the reaction of para‐formylcalix[4]arenes 1–6 with trialkyl phosphites in the presence of dry hydrogen chloride, calix[4]arenes 7–13 possessing dialkylphosphoryl‐hydroxymethyl groupings at the upper rim were synthesized. Calix[4]arenes 18–23 functionalized with dialkylphosphoryl‐alkyl(aryl)aminomethyl groups were obtained by sodium‐promoted addition of dialkyl phosphites to C=N bonds of para‐iminocalix[4]arenes 14–17 . The consecutive treatment of α‐hydroxy‐ or α‐aminophosphonic acid dialkyl esters of calix[4]arenes 7, 10, 18 , and 21 with bromotrimethylsilane and methanol gave dihydroxyphosphoryl derivatives of calix[4]arenes 24–27 . It was shown that calix[4]arenes bearing at the macrocyclic upper rim hydroxymethylphosphonic fragments, as well as bis‐hydroxymethyl(aminomethyl)phosphonic fragments, are able to undergo self‐assembly with formation of dimeric OH···O=P hydrogen bonded associates. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:58–67, 2001     

Reactions with 3,6‐diaminothieno[2,3‐b]‐pyridines: Synthesis and characterization of several new fused pyridine heterocycles

6‐Aminopyridine‐2(1H)thiones 1 reacting with α‐halo‐compounds 2a–c afforded the alkylthiopyridine derivatives 3a–c which in turn cyclized to the corresponding thieno[2,3‐b]pyridine derivatives 4a–c . Several thieno[2,3‐b]pyridine derivatives 7, 16, 19 , pyrido[3′,2′:4,5]thieno[3,2‐d]pyrimidine derivatives 6a,b, 11a–c, 21 and pyrido[3′,2′:4,5]thieno[3,2‐c]pyridazine derivatives 13, 17 were prepared starting from compounds 4a–c . © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:405–413, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20313     

Synthesis of Pyrano[4,3‐d]pyrimidine Derivative and Its Behaviour towards Nitrogen Nucleophiles and Active Methylenes

Pyrano[4,3‐d]pyrimidine derivative 3 was prepared by reaction of chlorocarbonyl isocyanate 1 with enaminonitrile 2 . Compound 3 reacted with nitrogen nucleophiles 4a‐f to afford 2‐substituted pyrido[4,3d]pyrimidine 5–8 , pyrimido[i]1,5a‐diaza‐9‐oxafluorene 9 and pyrimido[i]5a‐aza‐9‐thiafluorene 10 derivatives. Also, compound 3 reacted with active methylene compounds 4j to yield pyrimidine derivatives 14–16 which on reaction with EtONa 4k afforded 1,5,7‐triaza‐10‐oxaphenanthrene derivatives 17–19 .     

Synthesis and characterization of a novel organic–inorganic hybrid supramolecular recognition material and its selective adsorption for cesium

To separate Cs(I) from highly active liquid waste, a macroporous silica-based 25, 27-bis(iso-propyloxy)calix[4]arene-26,28-crown-6 (BiPCalix[4]C6) supramolecular recognition material, BiPCalix[4]C6/SiO₂–P, was synthesized and characterized by SEM, FT-IR, and TG-DSC. The adsorption properties of BiPCalix[4]C6/SiO₂–P and a macroporous polymer-based supramolecular recognition composite, BiPCalix[4]C6/XAD-7, were compared. It was found that BiPCalix[4]C6/SiO₂–P exhibited better adsorption ability and faster adsorption dynamics than BiPCalix[4]C6/XAD-7. The adsorption isotherm of Cs(I) onto BiPCalix[4]C6/SiO₂–P was studied at 298 K and it was well described by Langmuir isotherm model. The complex composition between BiPCalix[4]C6/SiO₂–P and Cs(I) was determined as 1:1 type by investigating the effect of the concentrations of BiPCalix[4]C6, Cs(I), and H⁺ on the adsorption. Meanwhile, the selectivity of BiPCalix[4]C6/SiO₂–P towards Na(I), K(I), Rb(I), Cs(I), Sr(II), Ba(II), Ru(III), Mo(VI), La(III), and Y(III) was investigated.     

Synthesis and some transformations of methyl [4-(oxoacetyl)phenyl]carbamate

The oxidation of methyl (4-acetylphenyl)carbamate with selenium dioxide in dioxane–water (30: 1) gave methyl [4-(oxoacetyl)phenyl]carbamate whose condensation with ethyl acetoacetate or diethyl malonate and hydrazine hydrate afforded ethyl 3-methyl-6-[4-(methoxycarbonylamino)phenyl]pyridazine-4-carboxylate and methyl {4-[5-(hydrazinecarbonyl)-6-oxo-1,6-dihydropyridazin-3-yl]phenyl}carbamate, respectively. The reaction of methyl [4-(oxoacetyl)phenyl]carbamate with o-phenylenediamine in dimethylformamide–ethanol on heating led to the formation of methyl [4-(quinoxalin-2-yl)phenyl]carbamate. Methyl {4-(5,7-dioxo- 4,4a,5,6,7,8-hexahydropyrimido[4,5-c]pyridazin-3-yl)phenyl}carbamate and methyl {4-(5-oxo-7-sulfanylidene- 4,4a,5,6,7,8-hexahydropyrimido[4,5-c]pyridazin-3-yl)phenyl}carbamate were synthesized by reactions of methyl [4-(oxoacetyl)phenyl]carbamate with barbituric and thiobarbituric acids, respectively, and hydrazine hydrate in the presence of zirconyl chloride octahydrate at room temperature.     

Syntheses of some new azolopyrido‐[4′,3′:4,5]thieno[2,3‐d]pyrimidines

Diethyl 2‐[(ethoxythioxomethyl)amino]‐4,5,6,7‐tetrahydrothieno[2,3‐c]‐pyridine‐3,6‐dicarboxylate 2 , prepared from diethyl 2‐isothiocyanato‐4,5,6,7‐tetrahydrothieno[2,3‐c]pyridine‐3,6‐dicarboxylate 1 by boiling in anhydrous ethanol, was converted into pyrido[4′,3′:4,5]thieno[2,3‐d]pyrimidine derivatives 3, 4 by treatment with hydrazine hydrate. The tetracyclic systems imidazo[1,2‐a]pyrido‐[4′,3′:4,5]thieno[2,3‐d]pyrimidine 9 and pyrido[4′,3′:4,5]thieno[2,3‐d][1,3]thiazolo‐[3,2‐a]pyrimidine 10 were synthesized by the reaction of 2 with 1,2‐diaminoethane and aminoethanethiol, respectively. The hydrazino derivative 4 underwent cyclization reactions with orthoesters and nitrous acid to give the corresponding pyrido[4′,3′:4,5]thieno[2,3‐d][1,2,4]triazolo[1,5‐a]pyrimidines 5, 6 and pyrido[4′,3′:4,5]thieno[3,2‐e][1,2,3,4]tetrazolo[1,5‐a]pyrimidine 8 , respectively. Moreover, reactions of 3 with cyanogen bromide, N‐carbethoxyhydrazine, carbon disulfide, and ethylchloroformate resulted in the formation of the new pyrido[4′,3′:4,5]thieno[2,3‐d][1,3,4]thiadiazolo[3,2‐a]pyrimidine derivatives 12–15 . © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:280–286, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10030     

A New Type of Donor–Acceptor Cyclopropane Reactivity: The Generation of Formal 1,2‐ and 1,4‐Dipoles

A new type of donor–acceptor cyclopropane reactivity has been discovered. On treatment with anhydrous GaCl₃, they react as sources of even‐numbered 1,2‐ and 1,4‐dipoles instead of the classical odd‐numbered 1,3‐dipoles due to migration of positive charge from the benzyl center. This type of reactivity has been demonstrated for new reactions, namely, cyclodimerizations of donor–acceptor cyclopropanes that occur as [2+2]‐, [3+2]‐, [4+2]‐, [5+2]‐, [4+3]‐, and [5+4]‐annulations. The [4+2]‐annulation of 2‐arylcyclopropane‐1,1‐dicarboxylates to give polysubstituted 2‐aryltetralins has been developed in a preparative version that provides exceedingly high regio‐ and diastereoselectivity and high yields. The strategy for selective hetero‐combination of donor–acceptor cyclopropanes was also been developed. The mechanisms of the discovered reactions involving the formation of a comparatively stable 1,2‐ylide intermediate have been studied.     

Synthesis,electrochemistry, and photophysical properties of pyrazolino[60]fullerene–1,8-naphthalimide fluorescent derivatives

A series of pyrazolino[60]fullerene–1,8-naphthalimide (Pz[60]–NI) fluorescent derivatives were synthesized in one pot by a [3+2] dipolar cycloaddition between C₆₀ and functionalized hydrazones in good yield. In contrast with 4-aziridino[60]fullerene–1,8-naphtalimide dyads, Pz[60]–NI derivatives present stronger fluorescence intensity. Electrochemical study revealed that Pz[60]–NI presents better electron accepting character than the parent C₆₀. The natural bond orbital of the dyads were calculated using density functional theory method and found that the sp3 nitrogen atom in the pyrazoline ring plays a key role in the charge transfer process.     

Synthesis and structures of zirconium complexes [Et2H2N]+2[ZrCl6]2–, [Me3NCH2Ph]+2[ZrCl6]2–•MeCN, [Ph3PC6H4(CHPh2-4)]+2[ZrCl6]2–•2 MeCN,and [Ph4Sb]+2[ZrCl6]2–

Russian Chemical Bulletin - The complexes [Et2H2N]+2[ZrCl6]2– (1), [Me3NCH2Ph]+2[ZrCl6]2–?MeCN (2), [Ph3PC6H4(CHPh2-4)]+2[ZrCl6]2–?2 MeCN (3), and...     

Radiosynthesis of New Carbon-11-labeled Nimesulide Analogs as Potential PET SAER Tracers for Imaging of Aromatase Expression in Breast Cancer

Carbon-11-labeled nimesulide analogs, N-[¹¹C]methyl-N-(2-benzyloxy-4-nitrophenyl)methanesulfonamide ([¹¹C]4a), N-[¹¹C]methyl-N-[2-(4′-methylbenzyloxy)-4-nitrophenyl]methanesulfonamide ([¹¹C]4b), N-[¹¹C]methyl-N-[2-(4′-fluorobenzyloxy)-4-nitrophenyl]methanesulfonamide ([¹¹C]4c), N-[¹¹C]methyl-N-[2-(4′-nitrobenzyloxy)-4-nitrophenyl]methanesulfonamide ([¹¹C]8a), N-[¹¹C]methyl-N-[2-(β-naphthylmethoxy)-4-nitrophenyl]methanesulfonamide ([¹¹C]8b), and N-[¹¹C]methyl-N-[2-(2′-phenylbenzyloxy)-4-nitrophenyl]methanesulfonamide ([¹¹C]8c), have been synthesized as new potential positron emission tomography (PET) selective aromatase expression regulator (SAER) radiotracers for imaging of aromatase expression in breast cancer. The target tracers were prepared by N-[¹¹C]methylation of their corresponding precursors using [¹¹C]CH₃OTf under basic conditions (NaH) and isolated by reversed-phase high-pressure liquid chromatography (HPLC) method in 30–50% radiochemical yields decay corrected to end of bombardment (EOB) with 25–30 min overall synthesis time and 111–148 GBq/μmol specific activity at end of synthesis (EOS).     

Synthesis and crystal structures of Ag and Hg complexes of bis(N-heterocyclic carbenes) on p-tert-butylcalix[4]arene platform

A series of p-tert-butylcalix[4]arene 1,3-diimidazolium salts were successfully prepared by the alkylation of p-tert-butylcalix[4]arene with dibromoalkanes, and sequential substitution reaction with 1-alkylimidazole. Furthermore, coordination reactions of p-tert-butylcalix[4]arene 1,3-diimidazolium salts with silver oxide and mercury acetate gave novel Ag and Hg complexes of bis(N-heterocyclic carbenes) on p-tert-butylcalix[4]arene platform. The single-crystal structures of four p-tert-butylcalix[4]arene 1,3-diimidazolium salts and three metal complexes were successfully determined by X-ray diffraction. An Ag–Ag argentophilic interaction (Ag–Ag bond length is 3.1599(6) Å) is formed between the two Ag–NHC complexes and a dimetallic coordination mode exists in Hg–NHC complexes.     

Synthesis and cytotoxicity studies of achiral azaindole‐substituted titanocenes

From the reaction of 1‐methyl‐1 H‐pyr‐rolo[2,3‐b]pyridine ( 1a ),1‐(methoxymethyl)‐1 H‐pyrrolo[2,3‐b]pyridine ( 1b ), 1‐isopropyl‐1 H‐pyrrolo[2,3‐b]pyridine (1c ), and 1‐(4‐methoxybenzyl)‐1 H‐pyrrolo[2,3‐b]pyridine ( 1d ) under Vilsmeier–Haak conditions, the corresponding aldehydes in position 3 ( 2a–2d ) were synthesized. These aldehydes were transformed in the corresponding fulvenes ( 3a–3d ) by the Knoevenagel condensation and treated with Li[BEt₃H] to obtain the corresponding lithiated cyclopentadienide intermediates ( 3′a–3′d ). These intermediates were, finally transmetallated to titanium with TiCl₄ to yield the 7‐azaindol‐3‐yl‐substituted titanocenes bis {[(1‐methyl‐1‐H‐pyrrolo[2,3‐b]pyridin‐3‐yl)methyl] cyclopentadienyl} titanium(IV) dichloride ( 4a ), bis{[(1‐methoxymethyl‐1‐H‐pyrrolo[2,3‐b]pyridin‐3‐yl)methyl]cyclopentadienyl} titanium(IV)dichloride ( 4b ), bis{[(1‐Isopropyl‐1‐H‐pyrrolo[2,3‐b]pyridin‐3‐yl)methyl]cyclopentadienyl} titanium(IV) dichloride ( 4c ), and bis{[(4‐methoxybenzyl‐1‐H‐pyrrolo[2,3‐b]pyridin‐3‐yl)methyl]cyclopentadienyl} titanium(IV) dichloride ( 4d ). All the titanocenes had their cytotoxicity investigated through MTT‐based preliminary in vitro testing on the Caki‐1 cell lines to determinate their IC₅₀ values. Titanocenes 4a–4c were found to have IC₅₀ values of 120 ± 10, 83 ± 13, and 54 ± 12, µM respectively, whereas 4d showed no cytotoxic activity. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:148–157, 2011; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20668     

Synthesis and pharmacological evaluation of 5-[2′-(1H-tetrazol-5-yl)-biphenyl-4-ylmethyl]-4,5,6,7-tetrahydro-thieno[3,2-c]pyridine derivatives as platelet aggregation inhibitors

One pot synthesis and characterization of new 5-[2′-(1H-tetrazol-5-yl)-biphenyl-4-ylmethyl]-4,5,6,7-tetrahydro-thieno[3,2-c]pyridines (3a–k) using amides (2a–k) were reported. The prepared 5-[2′-(1H-tetrazol-5-yl)-biphenyl-4-ylmethyl]-4,5,6,7-tetrahydro-thieno[3,2-c]pyridine (3a) is a bioisostere of 4′-(6,7-dihydro-4H-thieno [3,2-c]pyridin-5-ylmethyl)-biphenyl-2-carboxylic acid (1), having good in vivo antithrombotic activity compared with Clopidogrel. The new tetrazole derivatives (3a–k) were screened for their in vitro activity as platelet aggregation inhibitors.     

Donor-acceptor copolymers from cyclopentannulation polymerizations with dicyclopenta[cd,jk]pyrene and dicyclopenta[cd,lm] perylene acceptors

A series of donor-acceptor copolymers with dicyclopenta[cd,jk]pyrene and dicyclopenta[cd,lm]perylene acceptor units was prepared via palladium catalyzed cyclopenta-annulation reactions. The acceptor units were paired with diethynyl containing donor groups based on benzo[1,2-b:4,5-b’]dithiophene, thieno[3,2-b]thiophene, and 4-octyl-4H-dithieno[3,2-b:2′,3′-d]pyrrole to create six polymer variants. The cyclopentannulation polymerization resulted in copolymers with molecular weights (Mn) of 6–14 kDa and broad light absorption in the visible region with band gaps of 1.38–1.85 eV. The synthetic methodology, as well as optoelectronic properties, including thin-film absorption and cyclic voltammetry, of the donor-acceptor copolymers are presented.     

A regioselective 1,3-dipolar cycloaddition for the synthesis of novel spiro-chromene thiadiazole derivatives

A variety of 4′-(4-R-phenyl)-4-(methylthio)-2′-phenyl-2′H-spiro[chromene-2,5′-[1,2,3]thiadiazole] 5a–d and 5′-(4-R-phenyl)-4-(methylthio)-3′-phenyl-3′H-spiro[chromene-2,2′-[1,3,4]thiadiazole] 6a–d were synthesized regioselectively through the reaction of 4-(methylthio)-2H-chromene-2-thione 2 with diarylnitrilimines under refluxing dry chloroform. Whilst the reaction of 4-(allylthio)-2H-chromene-2-thione 3 with diarylnitrilimines under similar reaction conditions afforded the corresponding 4-(allylthio)-5′-(4-R-phenyl)-3′-phenyl-3′H-spiro[chromene-2,2′-[1,3,4]thiadiazole] 7a–d and 5-(4-R-phenyl)-2′-methyl-3-phenyl-2′,3′-dihydro-3H-spiro[[1,3,4]thiadiazole-2,4′-thieno[3,2-c]chromene] 9a–d as two unisolable diastereoisomeric forms. The structures of the obtained spiro cycloadduct thiadiazoles have been assigned by means of spectroscopic measurements.     

Synthesis of spiro[2H-indole-2,1′-1H-isoindole]-3,3′-diones,spiro[1H-isobenzofuran-1,2′-2H-indole]-3,3′-diones and spiro[benzofuran-2,1′-isobenzofuran]-3,3′-diones via transannular reactions of eight membered ring intermediates

An auto oxidation-rearrangement product 4 was isolated from a high dilution reaction of ninhydrin with 3,4,5-trimethoxyaniline in water. A general synthesis of this compound and its derivatives 4–6 was devised by oxidation of tetrahydroindeno[1,2-b]indol-10-ones 1–3 with sodium periodate to give isoindolo[2,1-a]-indole-6,11-diones 4–6 in good yield. Compounds 4–6 can be easily transformed into spiro[1H-isobenzofuran-1,2′-2H-indole]-3,3′-diones 8–10 , spiro[2H-indole-2,1′-1H-isoindole]-3,3′-diones 11–13 and isoindole[1,2-a:2′,1′-b]pyrimidine-5,15-diones 15, 16 in high yields. Analogous reactions were performed on 3-amino-5a, 10a-dihydroxybenzo[b]indeno[2,1-d]furan-10-one ( 17 ) to give a dibenzoxocintrione 18 , spiro-[benzofuran-2,1′-isobenzofuran]-3,3′-dione 19 and an isoindol-1-one 20 .     

Novel Disubstituted Calix[4]arenes Containing Chromogenic Groups on the Lower Rim: Synthesis,Structural Identification,and Absorption Properties

5,11,17,23‐Tetra‐tert‐butyl‐25,26,27,28‐tetrahydroxycalix[4]arene and 25,26,27,28‐tetrahydroxycalix[4]arene were synthesized based on previous literature. Firstly, several azo dyes were synthesized, and then, these dyestuffs were chlorinated through reaction with thionyl chloride. Secondly, the azo compounds bonded with methylene chloride and reacted with 25,26,27,28‐tetrahydroxycalix[4]arene, and then, six novel disazocalix[4]arene derivatives 4 ( a – f ) were achieved. Their structures were characterized as Fourier transform infrared, ¹H‐NMR, and elemental analysis. In this study, we investigated the solvatochromic properties of the compounds and the acid–base effect on their ultraviolet–visible absorption by using six solvents.     

Azocalixarenes.8: synthesis and investigation of the absorption spectra of di-substituted azocalix[4]arenes containing chromogenic groups

The synthesis of series of chromogenic di-substituted azocalix[4]arene derivatives is described. A ketone moiety as a different chelating agent is grafted on the lower rim of p-tert-butylcalix[4]arenes. Eight novel azocalix[4]arenes (1–8) are prepared by linking 2-, 3- and 4-nitroaniline, 4-phenylazoaniline, 3- and 4-chloroaniline or 2- and 4-methylaniline to 25,27-diacetonyloxy-26,28-dihydroxy-11,23-di-(tert-butyl)calix[4]arene through a diazo-coupling reaction, and characterized by UV–Vis, FT-IR and ¹H-NMR spectroscopic techniques and elemental analysis, consecutively. The absorption spectra of the di-substituted azocalix[4]arenes are discussed, according to effect of varying pH and solvent upon the absorption ability of azocalix[4]arenes. The colors of these azocalix[4]arenes are compared with respect to nature of their aromatic rings and substituents there in. Concentration effects on the visible absorption maxima of these compounds are also reported.     

Synthesis,characterization, optimum reaction conditions,and some polymer–metal complexes of poly(phenoxy-imine)s containing furan ring

In this study, Schiff bases containing azomethine (–HC=N–) compounds were synthesized from the condensation reaction of 4-aminophenol and 2-aminophenol and 5-methyl-2-furaldehyde. Orange-colored Schiff bases, 4-[(5-methyl- 2-furyl) methyleneamino] phenol (4MFMAP) and 2-[(5-methyl-2-furyl) methyleneamino] phenol (2MFMAP) turned to poly-4-[(5-methyl-2-furyl) methyleneamino] phenol (P-4MFMAP) and poly-2-[(5-methyl-2-furyl) methyleneamino] phenol (P-2MFMAP) polyazomethine derivatives by NaOCl oxidant in alkaline aqueous medium. In addition, poly-2-[(5-methyl-2-furyl) methyleneamino] phenol cobalt (II) and copper (II) complexes were synthesized. FTIR and NMR measurements for structural analysis of the synthesized compounds, UV–Vis analysis for optical properties, electrical conductivity measurements, and thermal analysis with the TG–DTA techniques were determined. The yield of P-4MFMAP and P-2MFMAP was found to be 84.6% and 78.6 as follows [4MFMAP] = 0.066, [KOH] = 0.198 [NaOCl] = 0.066 mol L^?1 at 60 °C for 3 h and [2MFMAP] = 0.066, [KOH] = 0.132 [NaOCl] = 0.066 mol L^?1 at 70 °C for 3 h, respectively.     

Studies on Organophosphorus Compounds: The Synthesis of [1,3,2]-Diazaphospholes and [1,3,2]-Oxaazaphospholes

A number of spiro[cyclopentane (cyclohexane, and cycloheptane)-1,4′-perhydro-[1,3,2]diazaphosphole] derivatives (3a–c, 5a–c, 11a–c, and 12a–c) and spiro-[cyclopentane (cyclohexane, and cycloheptane)-1,4′-perhydro[1,3,2]oxaazaphos-phole] derivatives (7a–c) were prepared via an interaction of 2,4-bis-(4-methoxy-phenyl)-1,3,2,4-dithiaphosphetane-2,4-disulphide (1) with substances containing two functional groups.