Derivate der 5,6-Dihydro-2H-pyran-3-carbonsäure

Summary Some derivatives of 5,6-dihydro-2H-pyran-3-carboxaldehyde (7) and of its oxidation product 5,6-dihydro-2H-pyran-3-carboxylic acid (8) have been prepared. The aldehyde derivatives as well as the amides and esters of8 have been tested in an insecticidal/fungicidal/acaricidal screening programme. The methylester35 shows a distinct knock down effect against the fruit flyDrosophila melanogaster.

     

Conformational peculiarities of a new heterocyclic dihydrothienothiopyranoisoxazole system

The crystalline and molecular structures of 3H-3a,4-dihydro-7-methylthieno[3,2:5,6]thiopyrano[4,3-c]isoxazole and 3H-3a,4-dihydro-3-isopropoxycarbonyl-3a,7-dimethylthieno[3,2:5,6]thiopyrano[4,3-c]isoxazole are determined by X-ray analysis. The effect of steric factors on intramolecular 1,3-dipolar cycloaddition is shown.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 302–304, February, 1995.This work was financially supported by the Russian Foundation for Basic Research (Project No. 93-03-18461).     

Synthesis of substituted 2-amino-5,6-dihydro-4h-1,3-oxazines and 2-iminotetrahydro-1,3-oxazines

3,4,4,6-Tetramethyl-2-aryliminotetrahydro-1,3-oxazines were synthesized by intramolecular cyclization of N-aryl-N′-methyl-N′-(2-methyl-4-hydroxy-2-pentyl)-S-methylisothioureas. 4,4,6-Trimethyl-2-(N-methyl-N-arylamino)-5,6-dihydro-4H-1,3-oxazines were obtained by methylation of 4,4,6-trimethyl-2-arylamino-5,6-dihydro-4H-1,3-oxazines.     

A new organic superconductor beta-(meso-DMBEDT-TTF)2PF6

A newly synthesized donor meso-DMBEDT-TTF [DMBEDT-TTF = 2-(5,6-dihydro-1,3-dithiolo[4,5-b][1,4]dithiin-2-ylidene)-5,6-dihydro-5,6-dimethyl-1,3-dithiolo[4,5-b][1,4]dithiin] afforded a superconducting salt beta-(meso-DMBEDT-TTF)2PF6, with a transition temperature at 4.3 K (onset) under a hydrostatic pressure of 4.0 kbar.     

Synthesis and Properties of 6,7,8-Substituted 2-(4-Oxo-3,4-dihydro-2-quinazolinyl)acetonitriles

2-(4-Oxo-3,4-dihydro-2-quinazolinyl)acetonitriles have been obtained by the interaction of -cyanoethylthioiminoacetate with substituted anthranilic acids. Prototropy became apparent in the series of synthesized compounds. Reactions of the 2-(4-oxo-3,4-dihydro-2-quinazolinyl)acetonitriles have been carried out with (hetero)aromatic aldehydes leading to the formation of 3-aryl-2-(4-oxo-3,4-dihydro-2-quinazolinyl)acrylonitriles.     

An efficient de novo synthesis of partially reduced phenanthrenes through C-C insertion

An efficient and novel approach to the synthesis of highly congested 3-alkyl-, 4-alkyl-, 3-aryl-, 3,4-dialkyl-, 4-alkyl-3-aryl-, and 3,4-diaryl-9,10-dihydro-1-sec-aminophenanthrene-2-carbonitriles has been delineated through the base-catalyzed ring transformation of 5,6-dihydro-2-oxo-4-sec-amino-2H-benzo[h]chromene-3-carbonitrile by carbanion derived in situ from various ketones in moderate to good yields. 9,10-Dihydrophenanthrenes with and without substituent in the bay region are efficiently and regioselectively synthesized by using propanal and acetyltrimethylsilane as a source of carbanion. Even the synthesis of bisphenanthrenes has been achieved by the ring transformation of 5,6-dihydro-2-oxo-4-sec-amino-2H-benzo[h]chromene-3-carbonitrile by 2-acetylphenanthrene in moderate yield. Highly substituted 3-amino-1-sec-amino-5,6-dihydrophenanthrene-2,4-dicarbonitriles have also been prepared from the reaction of 2-oxobenzo[h]chromene and malononitrile.     

A comparison of eight commercial reverse-phase (ODS) columns for the separation of hydroxylated derivatives of 7,12-dimethylbenz(a)anthracene

This paper presents an evaluation of a number of commercially available octadecylsilane columns. The separation of four 7,12-dimethylbenz(a)anthracene (DMBA) derivatives namelycis- andtrans-5,6-dihydroxy DMBA,trans-8,9-dihydro-8,9-dihydroxy DMBA, and 7,12-dihydroxymethyl benz(a)anthracene (BA) was compared under identical conditions comprising of a concave gradient (No. 4) from 20 to 70% acetonitrile/water for 75 minutes at flow rate of 1ml/min. A direct correlation between percent carbon loading and retention behavior was observed for bonded phases prepared from silica particles with similar surface areas. Other column performance parameters, such as capacity factors, separation ratios and resolution between peaks for the solutes examined were also calculated and are discussed.     

A facile synthesis of 5,6-dihydro-5-hydroxy-2(1H)-pyridone

A short synthesis of 5,6-dihydro-5-hydroxy-2(1H)-pyridone was achieved from l-serine employing Horner-Emmons olefination as the key step.     

Convenient synthesis of 5-aryl(alkyl)sulfanyl-1,10-phenanthrolines from 5,6-epoxy-5,6-dihydro-1,10-phenanthroline, and their activity towards fungal β-d-glycosidases

A broad series of novel 5-aryl(alkyl)sulfanyl-1,10-phenanthrolines has been prepared by a new simple procedure: a treatment of the commercially available 5,6-epoxy-5,6-dihydro-1,10-phenanthroline with various thiols in the presence of a base. Other functional groups attached to the thiol allow a use of the products as building blocks in synthesis of versatile ligands and in functionalization of surfaces. The synthesized phenanthrolines showed a moderate ability as activators or inhibitors of fungal β-d-glucosidases and β-d-galactosidases.     

Design of potential NO-synthase inhibitors on the basis of 2-amino-5,6-dihydro-4<Emphasis Type="Italic">H</Emphasis>-1,3-thiazine derivatives

Two spiro analogues of 2-amino-5,6-dihydro-4H-1,3-thiazine, a known NO-synthase inhibitor, were synthesized by means of cyclization of N-2-(1-cyclohexenyl)ethylthioureas.     

Synthesis of substituted 2-amino-5,6-dihydro-4h-1, 3-oxazines

4,4,6-Trimethyl-2-alkyl(aryl)amino-5,6-dihydro-4H-1,3-oxazines were synthesized via two methods: amination of 4,4,6-trimetiiyl-2-methylthio-5,6-dihydro-4H-1,3-oxazine and cyclization of N-aryl-N-(2-methyl-4-hydroxy-2-amyl)-S-methylisothiourea.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1037–1040, August, 1972.     

5,6-Dihydro-4H-imidazo[4,5,1-i,j]quinoline derivatives

9-Substituted 5,6-dihydro-4H-imidazo[4,5,1-i,j]quinolines were synthesized and aminated by the action of sodium amide and hydroxylated by fusing with potassium hydroxide. The mononitro and dinitro compounds of some 5,6-dihydro-4H-imidazo[4,5,1-i,j]quinoline deivatives and the corresponding amino and diamino compounds were obtained. The latter react with nitric or formic acids to form a new heterocyclic ring.See [1] for communication II.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 242–246, February, 1972.     

Synthesis of novel dispiro[indoline-3,2'-pyrrolidine-3',10”-thiazolo[3',2':1,2]pyrimido[5,4-g]indolizine] derivatives by 1,3-dipolar cycloaddition reaction

Chemistry of Heterocyclic Compounds - A number of 7-aryl-5,6-dihydro-7H-thiazolo[3',2':1,2]pyrimido[5,4-g]indolizines were synthesized by the reaction of...     

Nitro derivatives of 1,3-dihydrobenzimidazol-2-one: I. Synthesis of <Emphasis Type="Italic">N</Emphasis>-nitrobenzimidazol-2-ones

1,3,5,6-Tetranitro-2,3-dihydro-1H-benzimidazol-2-one, 1,5,6-trinitro-2,3-dihydro-1H-benzimidazol-2-one, and 1,4,5,6-tetranitro-2,3-dihydro-1H-benzimidazol-2-one were synthesized for the first time by nitration of 5,6-di- and 4,5,6-trinitro-2,3-dihydro-1H-benzimidazol-2-ones with concentrated nitric acid in acetic anhydride.     

Synthesis and Spectral,Electrochemical, and Antioxidant Properties of 2-(5-Aryl-6-R-3-phenyl-5,6-dihydro-4H-1,2,4,5-tetrazin-1-yl)-1,3-benzothiazoles

Russian Journal of Organic Chemistry - New 2-(5-aryl-6-R-3-phenyl-5,6-dihydro-4H-1,2,4,5-tetrazin-1-yl)-1,3-benzothiazoles were synthesized from the corresponding formazans by alkylation and...     

Copper complexes: cytotoxicity and transport possibilities

Russian Chemical Bulletin - A copper complex with N-(5,6-dihydro-4H-1,3-thiazin-2-yl)benzamide was synthesized for the first time and characterized by 1H NMR spectroscopy, LETDY mass spectrometry,...     

Synthesis of substituted 2-amino-5,6-dihydro-4H-1,3-thiazines and 2-iminotetrahydro-1,3-thiazines

N-Aryl-N′-(2-methyl-4-hydroxy-2-pentyl)thioureas are cyclized in acidic media to 4,4,6-trimethyl-2-arylimino-5,6-dihydro-4H-1,3-thiazines, the methylation of which with methyl iodide gives 4,4,6-trimethyl-2-methylarylamino-5,6-dihydro-4H-1,3-thiazines. 3,4,4,6-Tetramethyl-2-aryliminotetrahydro-1,3-thiazines were synthesized by cyclization of Naryl-N′-methyl-N′-(2-methyl-4-hydroxy-2-pentyl)thioureas.     

微波辐射下2-氨基苯并[h]喹唑啉衍生物的合成

2-芳亚甲基-3，4-二氢-2H-1（2H）-萘酮和碳酸胍在以乙二醇为溶剂、微波辐 射下反应，生成一系列新的2-氨基-4-芳基-5，6-二氢化苯并[h]喹啉衍生物，产物 的结构通过单晶X射线衍射分析确证。     

Synthesis and Reactivity of α-Bromo-4-(difluoromethylthio)acetophenone

A synthesis is reported for -bromo-4-difluoromethylthioacetophenone and the conditions for the condensation of this compound with 2-aminothiazole, 2-amino-5-chloropyridine, 2-amino-4,5-dihydro-3H-pyrrole, benzimidazoline-2-thione, oxadiazoline-2-thione, and thiourea were studied. S- and N-substituted azaheterocycles containing the 4-(difluoromethylthio)phenyl fragment were synthesized and characterized.     

Irregular linear sesquiterpene dilactones from Anthemis auriculata Boiss

Seven new irregular linear sesquiterpene lactones, epi-antheindurolide A (1), epi-antheindurolide A-5,6-oxide (2), 5-hydroxy-5,6-dihydro-6,13-dehydro-epi-antheinduro lide A (3), 5-hydroperoxy-5,6-dihydro-6,13-dehydro-epi-antheindurolide A (4), epi-antheindurolide B (5), 6-hydroxy-5,6-dihydro-4,5-dehydro-epi-antheindurolide A (6) and 6-hydroperoxy-5,6-dihydro-4,5-dehydro-epi-antheindurolide A (7), were isolated from the flowers of Anthemis auriculata Bioss. Their structures were established by spectroscopic techniques. The discussed compounds were found to be stereoisomers of recently reported lactones for A. arvensis.