A New Route to Pyrrolidines: One-Step Cyclization of 1,4-Azido Alcohol Synthesis of 1,4-Dideoxy-1,4-Imino-L-Lyxitol

Several optically active 3,4-dihydroxy-2-hydroxymethyl pyrrolidines are potent α-glycosidase inhibitors; for example, 1,4-dideoxy-1,4-imino-D-lyxitol (1) is a powerful inhibitor of α-galactosidase.¹ Furthermore, pyrrolidine 1 can be easily converted into the indolizidine alkaloid swainsonine to which it is structurally related.² (-) Swainsonine exhibits α-D-mannosidase inhibitory activity and immunoregulatory activity. Certain swainsonine stereoisomers have glycosidase inhibitory activity as well, and therefore have attracted considerable interest.³ 1,4-Dideoxy-1,4-imino-L-lyxitol (2) (enantiomer of 1) could be of biological interest. This communication describes the first synthesis of 2, starting from D-ribonolactone.     

Studies on the chemistry of 1,4-oxazines,XV: Synthesis of ethyl 3,4-dihydro-4-tosyl-2H-1,4-benzoxazine-3-carboxylate

A four step synthesis of ethyl 3,4-dihydro-4-tosyl-2H-1,4-benzoxazine-3-carboxylate (4) from the acetal5 is described.

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Studien zur Chemie der 1,4-Oxazine, 15. Mitt.: Synthese des 3,4-Dihydro-4-tosyl-2H-1,4-benzoxazin-3-carbonsäureethylesters (Kurze Mitteilung)

Zusammenfassung Eine Synthese des 3,4-Dihydro-4-tosyl-2H-1,4-benzoxazin-3-carbon-säureethylesters (4) über vier Stufen wird, ausgehend vom Acetal5, beschrieben.

     

New Synthesis of 1,4 Benzodiazepine-2,5-diones by Means of HCL Gas Catalyst

A new synthesis of 1,4- benzodiazepinediones 4 , particularly 1,4-dihydro1H-1,4-benzodiazepine-2,5-dione, 4c key intermediate of metabolites cyclopenin 9 , cyclopenol 10 , cyclopeptine 11 and dehydrocyclopeptine 12 , was achieved by action of dry HCl gas in DMF on compound 3 prepared from anthranilic acid derivative 1 and amino ester 2 .     

[3 + 3] Cycloaddition of aza-oxyallyl cations with 1,4-dithiane-2,5-diols for the construction of 3-thiomorpholinones

Abstract

Base-mediated [3?+?3] cycloaddition reaction of in-situ formed aza-oxyallyl cations and 1,4-dithiane-2,5-diols has been achieved under mild reaction conditions. This strategy provides direct and efficient access to prepare desired thiomorpholin-3-one derivatives in moderate-to-high yields. The approach features broad substrates scope and short reaction time. Moreover, the resulting products can be readily converted into other useful heterocyclic compounds including 2H-1,4-thiazin-3(4H)-ones and thiomorpholine-3,5-diones.     

Regioselective Synthesis of New Triheterocyclic Compounds from 1,4-Benzodiazepine

As part of our program on the synthesis of new heterocyclic compounds, we report here a one-step synthesis of [1,2,4]triazolo[4,3-d][1,4]benzodiazepine 3 and [1,2,4]oxadiazolo[4,5-d][1,4]benzodiazepine 5 by 1,3-dipolar cycloaddition of nitrilimines and nitrile oxides with 1,4-benzodiazepines 1.     

Synthesis,Characterization, and Antimicrobial Potential of Some 1,4-Disubstituted 1,2,3-Bistriazoles

Abstract

A convenient synthesis of some new 1,4-disubstituted 1,2,3-bistriazoles (3a–3f, 4a–4f, 6a–6b, 7a–7b) is reported via copper(I)-catalyzed Huisgen 1,3-dipolar cycloaddition of various terminal alkynes with 1,4-bis(azidomethyl)benzene and 1,6-diazidohexane. The synthesized compounds were characterized by spectral techniques including infrared, ¹H NMR, ¹³C NMR, and high-resolution mass spectrometry and tested in vitro for antimicrobial potential against Bacillus subtilis and Staphylococcus aureus (Gram-positive bacteria), Pseudomonas aeruginosa and Escherichia coli (Gram-negative bacteria), and Candida albicans and Aspergillus niger (fungi). Among the synthesized 1,4-disubstituted 1,2,3-bistriazoles, compounds 6a, 6b, and 7b displayed excellent antimicrobial potential against most of the tested strains.     

Synthesis and Reactivity of Substituted N-Hydroxy-1,4-dihydro-1,4-azaphosphorins

Abstract

The synthesis of substituted N-hydroxy-1,4-dihydro-1,4-azaphosphorins 4 has been carried out by adding the di (trimethylsilyl)peroxide 3 to the anion 2 generated from the addition of n-butyllithium to compound 1.     

Synthesis of difunctional 1,4-dimethyl-1,4-disilacyclohexanes

Transformations of HVinSiCl₂, HVinSi(Me)Cl, HVinSi(Me)Ph, and HVinSi(Me)NEt₂ in the presence of Pt catalyst were studied. In dilute solutions, the reaction gave a mixture of structural and stereoisomers of five- and six-membered disilacyclanes, resulting from intramolecular cyclization of the initially formed linear dimer. In the case of methyl(phenyl)disilacyclane, the structural isomers were separated andtrans-1,4-dimethyl-1,4-diphenyl-1,4-disilacyclohexane was isolated. The reaction of this product with HCl in the presence of AlCl₃ followed by hydrolysis resulted in the synthesis oftrans-1,4-dichloro- andtrans-1,4-dihydroxy-1,4-dimethyl-1,4-disilacyclohexanes. The structures of the structural and stereoisomers synthesized were confirmed by¹H,¹³C, and²⁹Si NMR and IR spectroscopies and mass spectrometry. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1734–1738, September, 1999.     

Quinazolines and 1,4-benzodiazepines LVII. 1H-1,4-benzodiazepines

The preparation of the title compounds 3 and 4 using two different methods of synthesis is described. These compounds are readily reduced to 2,3-dihydro-1H-derivatives 5 . Oxidation of 2-alkylthio-1H-1,4-benzodiazepines leads to the corresponding sulfoxides and sulfones. The oxidative rearrangement of sulfones 9 to a 2H-1,4-benzodiazepin-2-one derivative 10 is also given. The “normal” addition of azodicarboxylate together with an unusual addition of two moles of acetylenedicarboxylate to the enamine double bond of 1H compounds is discussed.     

Facile Synthesis of 1,4-Dihydropyridine Monocarboxylic Acids and Unsymmetric Dicarboxylates via Quaternary Ammonium Salts of 2-Aminoethyl 1,4-Dihydropyridine-3,5-dicarboxylates

Useful 1,4-dihydropyridine unsymmetric dicarboxylates [nitrendipine (1), nicardipine (2)] and monocarboxylic acid 4 were prepared from unsymmetric 2-aminoethyl methyl 1,4-dihydropyridine-3,5-dicarboxylates 2 and 3 via their corresponding quaternary ammonium salts 5–9.     

Über die Synthese von Derivaten des Fluoreno[1,9-ef-1,4-diazepins

Zusammenfassung Beim Behandeln von1-Chloracetylaminofluoren-9-on-oxim (6) mit verd. KOH entsteht 3,4-Dihydro-2H-fluoreno[1,9-ef]-1,4-diazepin-3-on-1-oxid (7); durch Erhitzen von 1-Aminoacetyl-amino-fluoren-9-on (10) sowie durch Kondensation von 1-Aminofluoren-9-on mit Glycinesterhydrochlorid wird 3,4-Dihydro-2H-fluoreno[1,9-ef]-1,4-diazepin-3-on (11) erhalten. Es wird bewiesen, daß es sich bei7 und11 um Derivate des Fluoreno[1,9-ef]-1,4-diazepins (2) handelt und daß7 das 1-Oxid von11 ist. Die Synthesen weiterer Derivate von2 werden beschrieben.

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On treating the oxime of 1-chloroacetylaminofluoren-9-one (6) with dilute aqueous potassium hydroxide, 3,4-dihydro-2H-fluoreno[1,9-ef]-1,4-diazepin-3-one-1-oxide (7), is formed; heating of 1-aminoacetylaminofluoren-9-one (10) and condensation of 1-aminofluoren-9-one with glycine ester hydrochloride both yield 3,4-dihydro-2H-fluoreno[1,9-ef]-1,4-diazepin-3-one (11). It is shown that both7 and11 are derivatives of fluoreno[1,9-ef]-1,4-diazepine (2) and that7 is the 1-oxide of11. The syntheses of several other derivatives of2 are reported.

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Herrn Prof. Dr.F. Wessely zum 70. Geburtstag.     

Efficient and Rapid Synthesis of Highly Functionalized Novel Symmetric 1,4-Dihydropyridines Using Glacial Acetic Acid as Solvent

A new series of 1,4-dihydropyridines bearing a pyrazole moiety in the 4-position were synthesized by a variation of the classical Hantzsch synthesis. The reaction of 1,3-diphenyl-1H-pyrazole-4-carbaldehyde 4a–n with 3-amino crotononitrile in the presence of glacial acetic acid afforded novel 3,5-dicyano-2,6-dimethyl 1,4-dihydropyridines 5a–n. The procedure has short reaction time (15–20 min), easy workup, and good yield of product. The structures of all synthesized compounds were well characterized by mass, infrared, ¹H and ¹³C NMR, and elemental analysis.     

Cu-catalyzed one-pot multicomponent approach for the synthesis of symmetric and asymmetric 1,4-dihydropyridine (1,4-DHP) linked 1,2,3-triazole derivatives

Abstract

Synthesis of various symmetric and asymmetric 1,4-DHP linked 1,2,3-triazole derivatives from economical and readily available starting materials via a convenient methodology in a single-pot method using CuSO₄·5H₂O as an efficient catalyst has been reported. The reaction proceeded efficiently under the optimized reaction conditions with excellent functional group compatibility providing the desired products in good yields. The method appears to be an efficient combinatorial strategy for the synthesis of new 1,4-DHP linked triazole derivatives.     

Synthesis and investigation of cytotoxicity of new N- and S,S-substituted-1,4-naphthoquinone (1,4-NQ) derivatives on selected cancer lines

1,4-Naphthoquinones (1,4-NQ) have been reported to possess a variety of pharma-cological properties including antibacterial, antifungal, antiviral, anti-inflammatory, anti-artherosclerotic, and anticancer effects. In this study, new N- and S,S-substituted-1,4-NQ derivatives were synthesized in excellent yields and were completely characterized by spectroscopic analysis IR, NMR (¹H and ¹³C), MS and microanalysis. The cytotoxic activities of 1,4-NQ derivatives were examined against to A-549, DU145, HCT-116 and MDA-MB-231 cancer cells. Among these compounds, 2-[4-(2-furoyl)piperazine-1-yl]-3-chloro-1,4-NQ 5 and 2,3-bis(cyclobuthylsulfanyl)-1,4-NQ 17 were identified as the most potent anticancer agents with cytotoxic activity against three cell lines (breast (MDA-MB-231), prostate (DU145), colorectal (HCT-116).     

Stereoselective Synthesis of Functionalized 1,4-Dienes

The article reports a stereoselective synthesis of functionalized 1,4-dienes 5, 6 by coupling allylic Baylis–Hillman acetates 1 and vinyl magnesium chloride at low temperature and in the presence of a catalytic amount of LiCuBr₂ (3%).     

Synthesis and Characterization of Nitrogen and Sulfur Containing 1,4-Naphthoquinones

Abstract

New N,S-disubstituted naphthoquinones were synthesized by reactions of S- and N-nucleophiles with 2,3-dichloro-1,4-naphthoquinone. 2-(Hexadecylthio)-3-(phenylamino)-naphthalene-1,4-dione 5a was synthesized by reaction of 2-chloro-3-(phenylamino)-naphthalene-1,4-dione 3a with hexadecanethiol 4a. The structures of the new synthesized naphthoquinone derivatives were determined by micro analyses and spectroscopic methods (FT-IR, ¹H NMR, ¹³C NMR, MS, and UV/Vis.). Photo- and electrochemical properties of selected compounds were investigated by using fluorescence spectroscopy and the cyclovoltammetry method.     

以D-樟脑酸与1,4-二（咪唑-1-基）丁烷为配体构筑的两个配位聚合物的结构与磁性

水热合成了2个以D-樟脑酸(D-H2cam)与1,4-二(咪唑-1-基)丁烷(1,4-bimb)为配体的配位聚合物:[Co(D-cam)(1,4-bimb)]n·4nH2O(1)和[Ni(D-cam)(1,4-bimb)]n(2)。通过X-射线单晶衍射,元素分析,红外光谱,XRD分析,热重,和磁性分析对其结构进行了表征。测定了这两个聚合物的磁性。结构分析表明,1为P2空间群,其链状结构由氢键作用连接形成二维结构;2为Pna21空间群,呈四重穿插的dia网络结构。     

ZnCl2 Promoted Formal (3+2) Cycloaddition Reactions of 2-Alkoxy-1,4-benzoquinones with 2H-Chromenes

A simple, mild, inexpensive and highly efficient method for the synthesis of 2,2-dimethyldihydropyranopterocarpans (4a–h and 5a–b) by formal (3+2) cycloaddition reactions of 2-alkoxy-1,4-benzoquinones (3a–b) with 2H-chromenes (1a–d and 2) using ZnCl₂ at room temperature has been developed.     

One new 1,4-napthoquinone derivative from the roots of Juglans mandshurica

A new 1,4-napthoquinone derivative, namely (S)-(-)-3-(8-hydroxy-1,4-dioxo-1,4-dihydro-naphthalen-2-yl)-3-(4-hydroxy-3-methoxyphenyl)-propionic acid methyl ester (1), was isolated from the roots of Juglans mandshurica Maxim. The structure was identified based on HR-ESI-MS, 1D and 2D NMR spectroscopic methods.     

Catalyst free synthesis of 2-Aryl-2H-benzo[b][1,4]oxazines and 3-Aryl-2H-benzo[b][1,4]thiazin-2-ones: An ultrasonication-assisted strategy

An ultrasonication-assisted synthesis of 2-Aryl-2H-benzo[b][1,4]oxazines and 3-aryl-2H-benzo[b][1,4]thiazin-2-ones has been established by reacting phenacyl bromides with 2-aminophenol and 2-aminothiophenol, respectively. This approach fosters flexibility in generating a diverse range of 1,4-benzoxazines and 1,4-benzothiazinones under catalyst-free reaction conditions. Further scope toward the synthesis of rarely occurring bis-benzoxazine adduct has also been explored, which enabled us to propose the reaction mechanism.