1,3-双[3-芳基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑-6-基]丙烷类化合物的合成

戊二酸(1)与3-芳基-4-氨基-5-巯基-1,2,4-三唑(2a～2o)在相转移催化剂四丁基碘化铵和POCl₃作用下, 高收率合成了一系列新的1,2-双[3-芳基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑-6-基]丙烷(3a～3o). 其结构经IR, ¹H NMR, MS和元素分析确证.     

Synthesis of a Series of Novel Chiral Aromatic Heterocyclic Macrocycles Containing L-Amino Acid and 2,5-Bisphenyl-1,3,4-triazole Subunits

An array of novel chiral aromatic heterocyclic macrocycles, which may show potential enantiomeric recognition to variable D- and L-amino acids, were synthesized in acceptable yield. The desired macrocycles 3a–c and 4a–c were obtained via the condensation reaction of chiral diamine intermediates 2a–c with 2,5-bis(o-chloroformylphenyl)-1,3,4-triazole 5 in a presence of Et₃N in a highly diluted dichloromethane solution at room temperature.     

Convenient synthesis of 4H-chromenyl-tetrahydro-2H-pyrancarboxylates and cleavage of chromone and pyran rings leading to 5-(2-hydroxybenzoyl)-2-(trifluoromethyl)-1,2-dihydropyridine-3-carboxylates

4H-Chromenyl-tetrahydro-2H-pyrancarboxylates 3a–k have been conveniently prepared by the reaction of 3-formylchromones 1a–k and ethyl 4,4,4-trifluoro-3-oxobutanoate 2a with good yields. Thus obtained 4H-chromenyl-tetrahydro-2H-pyrancarboxylates 3a–k were reacted with amines 4a–e to provide series of 5-(2-hydroxybenzoyl)-2-(trifluoromethyl)-1,2-dihydropyridine-3-carboxylates 5a–o. The reaction proceeded via Michael addition (C-N bond formation) and followed by cleavage of chromone and pyran rings (C-O bond cleavage) in one pot.     

Synthesis of o-carborane-C-carboxylates of certain natural terpene alcohols, sterols, phenols, and camphar oxime

Previously unreported esters 1b–20b were synthesized from natural terpene alcohols, sterols, plant phenols, and camphar oxime (1a–20a) by reaction with o-carborane-C-carboxylic acid chloride. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 434–436, September–October, 2006.     

Synthesis of 2,2′‐Bi‐2H‐3,3′‐diaryl‐1,4‐benzothiazines from α,α‐Dibromoacetophenones and o‐Aminothiophenol

Some 2,2′‐bi‐2H‐3,3′‐diaryl‐1,4‐benzothiazines (5a–f) were synthesized from α,α‐dibromoacetophenones and o‐aminothiophenol.     

N-CYANOIMIDO-PHOSPHONYL/S-METHYL THIOCARBONATES: FACILE,USEFUL REAGENTS FOR THE SYNTHESES OF HETEROCYCLIC PHOSPHONATES

N-Cyanoimido-(O,O-dialkyl) phosphonyl/S-methyl thiocarbonates 2 were synthesized as facile, useful synthons for preparation of 1,3,5-triazine-, 1,2,4-triazole-, and 1,2,4-oxadiazole-phosphonates through cyclization reaction with various binucleophilic reagents. In addition, when 2a was treated with o-phenylenediamine, benzimidazole-2-yl phosphonate was obtained through addition–elimination reaction.     

Synthesis and Conformational Studies of Unnatural Pyrimidine Nucleosides

ABSTRACT

Starting from 3,4-di-O-acetyl-L-rhamnal (6) and thymine (7) the unsaturated nucleosides 1-(2′,3′,6′-trideoxy-4′-O-acetyl-α- and β-L-erythro-hex-2′-enopyranosyl)-thymine (8a and 8b) were prepared in anomerically pure form. In solution 8a was shown to be present in the ⁵ H _o and ⁰ H ₅ conformations, whereas the predominant conformation of 8b was ⁵ H _o. Chemical transformation of 8a and 8b led to the saturated nucleosides 1-(2′,3′,6′-trideoxy-α- and β-L-erythro-hexopyranosyl)thymine (10a and 10b, respectively), which were converted into 1-(4′-azido-2′,3′,4′,6′-tetradeoxy-α- and β-L-threo-hexopyranosyl)thymine (12a and 12b). Preliminary biological studies showed that 9b was inactive against the HIV-1 and HIV-2 viruses.     

The synthesis of novel 4-(3,4-dimethoxyphenyl)chromenone-crown ethers and their cation binding,as determined using fluorescence spectra

o-Dihydroxy-4-(3,4-dimethoxyphenyl)-chromenones (coumarins; 3a,b) were synthesised from 1,2,3-trihydroxy- or 1,2,4-triacetoxybenzenes through a reaction with ethyl 3-(3,4-dimethoxyphenyl)-3-oxopropanoate in H₂SO₄ or CF₃COOH. The chromenone-crown ethers (4a–f) were prepared from the cyclic condensation of o-dihydroxy-4-(3,4-dimethoxyphenyl)chromenones (3a,b) with poly(ethylene glycol) ditosylates, in the presence of CH₃CN/alkali carbonates. The chromatographically purified original chromenone-crown ethers were identified by ¹H NMR, ¹³C NMR, MALDI-TOF mass spectrometry and elemental analysis. The 1:1 binding constants of Li⁺, Na⁺ and K⁺ with the chromenone-crown ethers were estimated in acetonitrile using fluorescence emission spectroscopy. The complexing-enhanced fluorescence spectra and complexing-enhanced quenching fluorescence spectra, along with the cationic recognition rules of the crown ethers allowed the ion binding powers to be determined.     

5-Anthracenylidene and 5-(4-Benzyloxy-3-methoxy)benzylidene-hydantoin and 2-Thiohydantoin Derivatives,Synthesis, and S-Alkylation

Abstract

5-Anthracenylidene- and 5-(4-benzyloxy-3-methoxy)benzylidene-hydantoin and 2-thiohydantoin derivatives 3a-g were prepared by condensation of anthracene-9-carboxaldehyde and 4-benzyloxy-3-methoxybenzylaldehyde with hydantoin and 2-thiohydantoin derivatives. Compounds 3a, b, f undergo Mannich reaction with formaldehyde and morpholine to give the corresponding Mannich products 4a–c. For the synthesis of alkylmercaptohydantoin 5a–o, the potassium salt of compounds 3a, b, e, f were reacted with an alkylhalide, either methyl iodide, phenacyl bromide, ethyl bromo acetate, allyl bromide, or methallyl bromide, under stirring at room temperature to afford the alkylmercaptohydantoins 5a–o. Acid hydrolysis of compounds 5a–c afforded the corresponding arylidene-hydantoin derivatives 3c, d, g. 2-Methylmercapto-hydantoin derivatives 5a, c were reacted with some secondary amines such as morpholine or piperidine to afford 5-(4-benzyloxy-3-methoxy)benzylidene-2-morpholino- or piperidino glycocyamidine derivatives 7a, 5-anthracenylidene-2-morpholin-, or piperidino glycocyamidine derivatives 7b, c.

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.

GRAPHICAL ABSTRACT     

Synthesis of some schiff bases of 3-aroyl-6-aryl-4-hydroxy-2H-pyran-2-ones

Summary The reaction of 3-aroyl-6-aryl-4-hydroxy-2H-pyran-2-ones (Ar=p-tolyl, 1,1-biphenyl-4-yl or thienyl) with aniline and substitutedo-phenylenediamine (R=H, CH₃ or Cl) yields a series of new Schiff bases2a–f in 51–72% yield. Bromination of1a gave the 5-bromo derivative1c, while the compounds1a,1b,2b,2e, and2f were converted into 2,6-diaryl-4H-pyran-4-ones3a–c. All products have been fully characterized.

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Synthese von Schiff'schen Basen von 3-Aroyl-6-aryl-4-hydroxy-2H-pyran-2-onen

Zusammenfassung Die Reaktion von 3-Aroyl-6-aryl-4-hydroxy-2H-pyran-2-onen (Ar=p-Tolyl, 1,1-Biphenyl-4-yl oder Thienyl) mit Anilin und substituierteno-Phenylendiaminen liefert neue Schiff'sche Basen2a–f/bd in 51–72% Ausbeute. Bromierung von1a gab das 5-Bromderivate1c, während die Verbindungen1a,1b,2b,2e und2f in 2,6-Diaryl-4H-pyran-4-onen3a–c übergeführt wurden. Alle Produkte wurden voll charakterisiert.

     

Synthesis of 2-(Substituted Benzylideneamino)-4-(4′-hydroxyphenyl) Thiazoles and Their O-Glucosides

2-Amino-4-(4′-hydroxyphenyl) thiazole 1a was prepared from reaction between p-hydroxyacetophenone, thiourea, and iodine; compound 1a was treated with several (aryl/hetro aryl) aldehydes to form 2-(substituted benzylideneamino)-4-(4′-hydroxyphenyl) thiazoles 2a–j, which were glucosylated by using acetobromoglucose as a glucosyl donor to afford 2-(substituted benzylideneamino)-4-(2, 3, 4, 6-tetera-o-acetyl-4′-o-β-d-glucosidoxyphenyl) thiazoles 3a–j, which further on during deacetylation produced 2-(substituted benzylideneamino)-4-(4′-o-β-d-glucosidoxyphenyl) thiazoles 4a–j. These compounds were evaluated for biological activity, and their structure was confirmed by IR, NMR, mass spectra, elemental, and chemical analysis.

     

Reaction of enol type acyl cyanide with o-aminophenol

The reaction of 7-chloro-4-(2-cyano-2-hydroxyvinyl)tetrazolo[1,5-a]quinoxaline 2a with o-aminophenol gave 7-chloro-4-(b-hydroxyphenylcarbamoylmethylene)4,5-dihydrotetrazolo[1,5-a]quinoxaline 4 , while the reaction of compound 2a with o-aminophenol hydrochloride afforded 4-[2-(2-benzoxazolyl)-2-hydroxyvinyl]-7-chlorotetrazolo[1,5-a]quinoxaline 5 , whose acetylation provided 4-[2-acetoxy-2-(2-benzoxazolyl)vinyl]-7-chlorotetrazolo[1,5-a]quinoxaline 6 . The behavior in a deuteriodimethyl sulfoxide or deuteriotrifluoroacetic acid solution is described for compounds 4–6 .     

Synthesis of Some Prospective Bioactive Azeto[2,1-d][1,5]benzothiazepinones

Ten azeto[2,1-d][1,5]benzothiazepinone derivatives 6a–j were synthesized starting from 4-acetyl-2-phenyl-1,2,3-triazole 1. First, condensation of 1 with various aldehydes 2a–e afforded α,β-unsaturated carbonyl compounds 3a–e, which subsequently underwent cyclization with o-aminothiophenol to yield the corresponding 2,4-disubstituted-1,5-benzothiazepines 4a–e. Treatment of 4a–e with chloroacetyl chloride 5a or phenoxyacetyl chloride 5b by [2+2] cycloaddition reaction gave the title compounds 6a–j. The assignment of the structures of 6a–j was made by ¹H NMR, MS, and elemental analyses.     

Ring closure reactions with nitriles. II. Formation of pyrrolo[1,2-a] quinazolines and thiazolo[3,2-a] quinazolines

2-Quinazolinepropionic acids have been obtained from the reactions of potassium cyanide with o-carboxy- or o-acyl-3-chloropropionanilides. Some of these compounds have been cyclized to pyrrolo [1,2-a] quinazolines. The reaction of an o-carbethoxy-2-chloroacetanilide with potassium thiocyanate formed a 2-quinazolinylthioacetic acid, which was cyclized to a thiazolo-[3,2-a]quinazoline. A mechanism is presented for the formation of these compounds.     

HYDROGENATION OF A DELOCALIZED DIIMINATE SIX-MEMBERED CHELATE RING IN TETRAAZAMACROCYCLIC NICKEL(II) COMPLEXES BY SODIUM BOROHYDRIDE IN WATER—EFFECT OF PROTONATION-DEPROTONATION EQUILIBRIA AND STEREOSELECIVE REDUCTION

Abstract

Charge delocalized diiminate six-membered chelate rings in the 5,7-dimethyl-1,4,8,11-tetraazacyclotetradecane-4,6-dienatonickel(II) ion(1) and the α,α′-bis(5,7-dimethyl-1,4,8, 11-tetraazacyclotetradeca-4,6-dienato-6-yl)-xylenedinicke(II) ion(2) were hydrogenated in aqueous media by sodium borohydride. In the reduction reactions, control of the pH of the reaction mixture was essential, and the pH of the solution was kept during the reaction at 3 and at 5–6 for hydrogenations of 1 and 2, respectively. The delocalized diiminate chelate ring is in protonation-deprotonation equilibrium with the β diimine form and the pK_a of the equilibrium for 2 was determined to be 9.0 for 2a (o-xylylene bridged complex), 9.3 for 2b (m-xylylene bridged complex), and 10.0 for 2c (p-xylylene bridged complex). The appropriate pH values in the hydrogenation reactions were based on the pK_a′s. X-ray structure analyses on two reduction products of 1 show that the chirality of the two asymmetric carbons in the cyclam ring is of the meso-form in the major reduction product whereas that in the minor product is of the racemic form. In the major reduction product of 2, two chiral carbons in each cyclam ring take the meso-form.     

C‐C Bond Formation by Radical Cyclization: Regioselective Synthesis of [6,6] Pyrano pyran System

Abstract

Abstract:?A number of 4‐aryloxymethyl pyrano[3,2‐c][1]benzopyran‐5‐(2H)‐ones 3(a–f) were prepared by refluxing 4‐chloromethyl pyrano[3,2‐c][1]benzopyran‐5‐(2H)‐ones 1(a,b) with o‐bromophenols 2(a–c) in acetone in the presence of anhydrous potassium carbonate and sodium iodide in 70–80% yield. Compounds 3(a–f) were then subjected to radical cyclization by refluxing with tri‐n‐butyltin chloride, sodium cyanoborohydride, and azobisisobutyronitrile (AIBN) in dry benzene for 4–5 h to give a cis‐diastereomeric mixture of [6,6]pyranopyran derivatives in 80–85% yield.     

Heterocycles from Pyrazoloylhydroximoyl Chloride: Synthesis of Certain Quinoxaline,Benzothiadiazine, Benzoxadiazine,Quinazolinone, Imidazo[1,2-a]pyridine,Imidazo[1,2-a]pyrimidine,Isoxazole, Pyrazolo[3,4-d]pyridazine and Pyrrolidino[3,4-d]isoxazolin-4,6-dione Derivatives

3-Ethoxycarbonyl-5-methyl-1-(4-methylphenyl)-4-pyrazoloylhydroximoyl chloride (1) reacted with o-phenylenediamine, o-aminothiophenol, o-aminophenol and methyl anthranilate to afford 3-nitrosoquinoxaline, benzothiadiazine, benzoxadiazine, and 3-hydroxyquinazoline, respectively. Imidazo[1,2-a]pyridine, imidazo[1,2-a]pyrimidine and isoxazole derivatives were obtained via the reaction of 1 with 2-aminopyridine, 2-aminopyrimidine and the appropriate active methylene compounds, respectively. Pyrazolo[3,4-d]pyridazines, and pyrrolidino[3,4-d]isoxazolines derivatives were also synthesized. The structures of the newly synthesized compounds were established on the basis of spectral data and alternate synthesis whenever possible.     

Über Reaktionen von Nitrosophenolen, 2. Mitt.: Reaktion von 1-Nitroso-2-naphthol mit Orein

Zusammenfassung In der vorliegenden Arbeit wurde die Reaktion von 1-Nitroso-2-naphthol mit Orcin in Äther bei Anwesenheit von HNO₃ studiert. Als Reaktionshauptprodukte wurden 11-Methylbenzo[a]-phenoxazon-(9) (1) sowie dessen 12-Oxid (2) isoliert. Der Reaktionsmechanismus und die Konstitution der erhaltenen Substanzen werden diskutiert. Ferner wurden auch 11-Methyl-5-hydroxy-benzo[a]phenoxazon-(9) (6), 11-Methyl-5-äthoxybenzo[a]phenoxazon-(9), 11-Methyl-5-methoxybenzo[a]phenoxazon-(9) (4), 11-Methyl-5-aminobenzo[a]phenoxazon-(9) (7) und 11-Methyl-5-anilinobenzo[a]phenoxazon-(9) (8) dargestellt.

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In this paper the reaction of 1-nitroso-2-naphthol with orcin in an ether medium in presence of HNO₃ is described. As main products 11-methylbenzo[a]phenoxazone-(9) (1) as well as its 12-oxide (2) were isolated. The reaction mechanism is presented. Identity of the reaction products is verified. 11-methyl-5-hydroxybenzo[a]phenoxazone-(9) (5), 11-methyl-5-methoxybenzo[a]phenoxazone-(9) (4), 11-methyl-5-aminobenzo[a]phenoxazone-(9) (7) and 11-methyl-5-anilinobenzo[a]phenoxazone-(9) (8) are prepared.

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Mit 2 Abbildungen     

Condensation of 4-chloro-2H-chromene-3-carbaldehydes and ethyl-3-aminocrotonates with p-TsOH: a facile approach for the synthesis of chromenyldihydropyridines

The investigated reaction of 4-chloro-2H-chromene-3-carbaldehyde 1a with ethyl 3-oxobutanoate 2a in the presence of ammonium acetate provided two compounds, 2H-chromenyldihydropyridine dicarboxylate 3a and chromenopyridine carboxylate 4a. However, the reaction of 1a with ethyl-3-aminocrotonate 5a in the presence of p-TsOH provided selectively 2H-chromenyldihydropyridine dicarboxylate 3a with very good yield. The established method was applied for the preparation of series of 2H-chromenyldihydropyridine dicarboxylates 3a–q.     

Chemoselectivity of 6-bromo-2-methyl-3,1-benzoxazin-4-one towards amines,Schiff bases,and azines

Summary 6-Bromo-2-methyl-3,1-benzoxazin-4-one (1) undergoes an unusual cleavage at position 4 when it is allowed to react witho-phenylenediamine or anthranilic acid in dry benzene to give the corresponding compounds2–5, respectively. The reaction of1 withSchiffbases and azines results in the formation of the compounds6a–d and8a,b, respectively. The reaction involves a cleavage of theSchiff base or the azine into its amine and arylidene moieties which are smoothly incorporated into1 via nucleophilic attack of the amine at position 4 and condensation of the aldehyde with a reactive methyl group, at position 2 respectively. No displacement of the arylidene segment was observed.

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Zur Chemoselektivität von 6-Brom-2-methyl-3,1-benzoxazin-4-on gegenüber Aminen,Schiffschen Basen und Azinen

Zusammenfassung 6-Brom-2-methyl-3,1-benzoxazin-4-on reagiert mito-Phenylendiamin oder Anthranilsäure in trockenem Benzol unter einer ungewöhnlichen Bindungstrennung zu den Verbindungen2–5. Die Reaktion von1 mitSchiffschen Basen und Azinen führt zu den Verbindungen6a–d und8a,b. Die Reaktion verläuft über eine Spaltung derSchiffschen Base oder des Azins in ihre Amin- und Arylidenreste, die über einen nucleophilen Angriff des Amins an Position 4 und Kondensation des Aldehyds mit der reaktiven Methylgruppe in Position 2 glatt in1 übergeführt werden. Es wurde kein Arylidenaustausch beobachtet.