Reactions of <Emphasis Type="Italic">N</Emphasis>-acetyl- and <Emphasis Type="Italic">N</Emphasis>-ethoxycarbonyl-2-(1-cycloalken-1-yl)anilines with <Emphasis Type="Italic">meta</Emphasis>-cloroperbenzoic acid

Reaction of N-ethoxycarbonyl-2-(1-cycloalken-1-yl)anilines with meta-cloroperbenzoic acid leads to the corresponding 2-[1-o-(3-chlorobenzoyl)-2-hydroxycyclopent-1-yl]anilines. 5-(2-Acetylaminophenyl)-5-oxopentanic or 6-oxohexanic acids are formed as main products in the reaction of N-acetyl-2-(1-cycloalken-1-yl)anilines with m-chloroperbenzoic acid in CH₂Cl₂. N-Acetyl-2-(1-cyclopenten-1-yl)-3,6-dimethylaniline is an exception in this series since its reaction stops at the stage of epoxide formation.     

Reactions of <Emphasis Type="Italic">N</Emphasis>-and <Emphasis Type="Italic">C</Emphasis>-Alkenylanilines: VII. Synthesis of Indole Heterocycles from Products of Reaction between <Emphasis Type="Italic">N</Emphasis>-Mesyl-2-(1-alken-1-yl)anilines and Halogens

N-Mesyl-2-(1-methyl-1-butenyl)-6-methylaniline reacted with Br₂ to afford N-mesyl-2-(3-bromo-1-penten-2-yl)aniline that under treatment with NH₃ or amines underwent cyclization into N-mesyl-7-methyl-3-methylene-2-ethylindoline. The reaction of N-mesyl-2-(1-methyl-1-buten-1-yl)-4-methyl- and 2-(1-methyl-1-buten-1-yl)aniline with Br₂ gave rise to the corresponding N-mesyl-2-(2-bromo-1-methyl-1-buten-1-yl)anilines. Under the similar conditions N-tosyl-2-(1-cyclohexen-1-yl)aniline was converted into N-tosyl-2-(6-bromo-1-cyclohexen-1-yl)aniline that under treatment with NH₃ furnished N-tosyl-1,2,3,9a-tetrahydrocarbazole. The reaction of N-mesyl-1,2,3,9a-tetrahydrocarbazole with CuBr₂ in MeOH afforded N-mesyl-4-methoxy-1,2,3,4-tetrahydrocarbazole. N-Mesyl-6-methyl-2-(1-cyclopenten-1-yl)aniline in reaction with Br₂ in the presence of NaHCO₃ was oxidized into the corresponding cyclopentenone, and with NBS it gave N-mesyl-2-(2-bromo-1-cyclopenten-1-yl)aniline.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 5, 2005, pp. 730–737.Original Russian Text Copyright © 2005 by Gataullin, Sotnikov, Spirikhin, Abdrakhmanov.     

Synthesis of New 1,2,3,4-Tetrahydroisoquinoline Derivatives. 2-(2,3,3-Trimethyl-1,2,3,4-tetrahydroisoquinolin-1-yl)anilines

A four-step procedure has been developed for the synthesis of new 2-(2,3,3-trimethyl-1,2,3,4-tetrahydroisoquinolin-1-yl)anilines by acylation of 2-(3,3-dimethyl-3,4-dihydroisoquinolin-1-yl)anilines at the amino group with isobutyryl chloride, reduction of the endocyclic C=N bond in N-[2-(3,3-dimethyl-3,4-dihydroisoquinolin-1-yl)phenyl]isobutyramides, N-alkylation of N-[2-(3,3-dimethyl-1,2,3,4-tetrahydroisoquinolin-1-yl)phenyl]isobutyramides to N-[2-(2,3,3-trimethyl-1,2,3,4-tetrahydroisoquinolin-1-yl)phenyl]isobutyramides, and acid hydrolysis of the latter.     

Complete assignments 1H and 13C NMR spectral data of four anabaseine derivatives

The anabaseine derivatives 6-methoxy-7-hydroxy-1-(pyridin-3-yl)-3,4-dihydroisoquinoline, 6,7-dimethoxy-1-(pyridin-3-yl)-1,2,3,4-tetrahydroisoquinoline and 6,7-dimethoxy-1-(piperidin-3-yl)-1,2,3,4-tetrahydroisoquino- line were prepared either by demethylation with HBr or by reduction with different reagents, NaBH4 and H2/PtO2 from 6,7-dimethoxy-1-(pyridin-3-yl)-3,4-dihydroisoquinoline, as starting material. The structures have been fully assigned by the combination of one- and two-dimensional experiments.     

Anodic hydroxylation of 1-carbomethoxy-1,2,3,4-tetrahydrocarbazoles

1-Carbomethoxy-1,2,3,4-tetrahydrocarbazole (1) and its 7-methoxy derivative (2) were oxidized at carbon felt anodes in acetonitrile containing 0.2 M LiClO₄ and 2-17 M water at potentials on the rising portion of the primary oxidation peak to yield products formed by formal substitution of the C-1 H atom with hydroxide. The resulting 1-hydroxy-l-carbomethoxy-1,2,3,4-tetrahydrocarbazole and its 7-methoxy derivative were isolated in 44 and 22% yields, respectively, when sodium bicarbonate was used to control acidity of the medium. Structures were elucidated by NMR, IR, elemental analysis, and mass spectrometry. Voltammetry at carbon-paste and glassy carbon electrodes showed that the oxidations proceed by an ECE or DISPI pathway. The rate-determining step is the reaction of water with a cation radical electrochemically generated from 1 or 2, involving either proton abstraction or nucleophilic addition.     

Dehydrogenation of 1,2,3,4-tetrahydroquinoline and its related compounds: comparison of Pd/C-ethylene system and activated carbon-O2 system

Dehydrogenation of substituted 1,2,3,4-tetrahydroquinoline, 1,2,3,4-tetrahydroisoquinoline, and 1,2,3,4-tetrahydrocarbazole proceeded using Pd/C-ethylene system (method A) or activated carbon-O₂ system (method B) to give the corresponding heteroaromatic compounds.     

Die massenspektrometrische Retro-Diels-Alder-Reaktion: 1,2,3,4-Tetrahydrocarbazol. 30. Mitteilung über massenspektrometrische Untersuchungen

The mass spectral retro Diels-Alder-reaction: 1,2,3,4-tetrahydrocarbazole 1,2,3,4-Tetrahydrocarbazole undergoes a retro Diels-Alder-reaction under electron impact. C(2) and C(3) are eliminated as ethylene. This is shown by measuring the deuterated derivatives 1a , 1b and 1c . Furthermore the oxo-1,2,3,4-tetrahydrocarbazole derivatives 3 and 4 are investigated in respect to the mass spectral retro Diels-Alder reaction too.     

Total synthesis of (±)-fangchinoline

(±)-Fangchinoline was synthesized by condensation of (±)-1-(3-bromo-4-methoxy-benzyl)-2-methyl-6-methoxy-7-hydroxy-8-bromo-1,2,3,4-tetrahydroisoquinoline ( 2 ) and (±)-1-(4-hydroxy-benzyl)-2-methyl-6-methoxy-7-hydroxy-1,2,3,4-tetrahydroisoquinoline ( 3 ) in the presence of copper, pyridine and potassium carbonate.     

Synthesis and in vitro evaluation of N-(Bromobut-3-en-2-yl)-7-methoxy-1,2,3,4-tetrahydroacridin-9-amine as a cholinesterase inhibitor with regard to Alzheimer's disease treatment

A new tacrine based cholinesterase inhibitor, N-(bromobut-3-en-2-yl)-7-methoxy-1,2,3,4-tetrahydroacridin-9-amine (1), was designed and synthesized to interact with specific regions of human acetylcholinesterase and human butyrylcholinesterase. Its inhibitory ability towards cholinesterases was determined and compared to tacrine (THA) and 9-amino-7-methoxy-1,2,3,4-tetrahydroacridine (7-MEOTA). The assessment of IC50 values revealed 1 as a weak inhibitor of both tested enzymes.     

Synthesis and dehydration reaction of 1-(4-benzyloxyphenyl)-6-methoxy-2-phenyl-1,2,3,4-tetrahydronaphth-2-ol: possible intermediate of Lasofoxifene

The paper deals with a simple and sufficient synthesis of key precursor of Lasofoxifene. The 1-(4-benzyloxyphenyl)-6-methoxy-2-phenyl-3,4-dihydronaphthalene was prepared by a sequence of five reactions steps: first 1-(4-benzyloxyphenyl)-6-methoxy-3,4-dihydronaphthalene was prepared (70%), and this was quantitatively epoxidized to 7b-[4-(benzyloxy)phenyl]-5-methoxy-1a,2,3,7b-tetrahydronaphtho[1,2-b]oxirene. Catalytic (ZnI₂) isomerization of the epoxide gave 1-(4-benzyloxyphenyl)-6-methoxy-1,2,3,4-tetrahydronaphthalen-2-one (75%). Its subsequent reaction with phenylmagnesium bromide gave 1-(4-benzyloxyphenyl)-6-methoxy-2-phenyl-1,2,3,4-tetrahydro-2-naphthol (87%). Acid-catalysed dehydration of this alcohol by polyphosphoric acid (25°C) provides 1-(4-benzyloxyphenyl)-6-methoxy-2-phenyl-1,4-dihydronaphthalene (80%). Dehydration in the system of acetic anhydride/polyphosphoric acid gives 1-(4-benzyloxyphenyl)-6-methoxy-2-phenyl-3,4-dihydronaphthalene (66%).     

Formation of Benzo[e]cycloalk[g][1,4]oxazocinones by Reaction of N-Mesyl- or N-Tosyl-N-2-[(1-cycloalken-1-yl)phenyl]glycines with Molecular Bromine

Russian Journal of General Chemistry - The synthesis of new cycloalkene annelated benzoxazocinones from N-tosyl- or N-mesyl-N-[2-(1-cycloalken-1-yl)phenyl]glycines was reported. Upon stirring of...     

Synthesis of 6-Methyl-4-(1-methyl-2-buten-1-yl)-2-(2-cyclohexen-1-yl)- and 6-Methyl-4-(1-methyl-2-buten-1-yl)-2-(1-cyclohexen-1-yl)anilines

Alkenylation of 6-methyl-2-(2-cyclohexen-1-yl)- and 2-(1-cyclohexen-1-yl)anilines with piperylene in the presence of AlCl₃ and transformation of the resulting cyclohexenylanilines into carbazole structures were studied.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 3, 2005, pp. 441–443.Original Russian Text Copyright © 2005 by Gataullin, Ishberdina, Sotnikov, Abdrakhmanov.     

Reactions of N- and C-Alkenylanilines: III. Synthesis and Cyclization of Substituted 2-(1-Methyl-2-butenyl)anilines

Reactions of substituted 2-(1-methyl-2-butenyl)anilines with iodine result in cyclization and formation of 3-iodo-1,2,3,4-tetrahydroquinolines; N-methylsulfonyl-2-(1-methyl-2-butenyl)anilines give rise exclusively to the corresponding 2-(1-iodoethyl)-3-methyl-2,3-dihydroindoles.     

Chirally N-Substituted Indole-2-carbaldehydes. Preparation and Use in Asymmetric Synthesis

A simple method is proposed for the synthesis of optically active indole-2-carbaldehydes via alkylation of 2-cyanoindole by optically active secondary alcohols and subsequent reduction of the cyano group to an aldehyde. Reaction of the aldehydes obtained with aromatic amines gave imines whose reaction with the Danishefsky diene was studied. The structure of the major diastereomer of (2R′)-1-phenyl-2-[1-((1R′)-1-phenylethyl)indol-2-yl]-1,2,3,4-tetrahydropyridine-4-one and minor diastereomer (2S)-2-[1-((1S)-2-methoxy-1-phenylethyl)indol-2-yl]-1-phenyl-1,2,3,4-tetrahydropyridine-4-one respectively were established by X-ray analysis. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1540–1550, October, 2005.     

Synthesis and X-ray diffraction study of 5-(8-methoxy-2-methyl-6,7-methylenedioxy-1,2,3,4-tetrahydroisoquinolin-1-yl)-1,3-dimethylbarbituric acid

The reaction of cotarnine with 1,3-dimethylbarbituric acid afforded 5-(8-methoxy-2-methyl-6,7-methylenedioxy-1,2,3,4-tetrahydroisoquinolin-1-yl)-1,3-dimethylbarbituric acid. Its crystal structure was established by X-ray diffraction analysis and the structure in solution was studied by ¹H NMR spectroscopy. This compound has a zwitterionic structure. In the crystal, the molecules are linked in dimers by intermolecular hydrogen bonds, and in solutions, the dimers occur in equilibrium with the monomers.     

Investigations toward the total syntheses of proapoiphine and homoproaporphine alkaloids

The reaction of 1,2,3,5-telrahydro-6-methoxy-1 -[2-(4-methoxy-1,4-eyelohexadien-1 -yl)eth-yl]-l-methyl-7-isoquinolinol ( 12 ) with hot phosphoric acid afforded (±)-tetrahydro-homoglazio-vine ( 14 ) in good yield. Similar treatment of 1,2,3,4-tetrahydro-6-methoxy-l -[2-(4-methoxy-1,4-cyelohexadien-l-yl)methyl]-2-methyl-7-isoquinolinol ( 13 ) did not produce the desired (±)-tetra-hydroglaziovine ( 18 ) but rather a mixture of diastereomeric 4,5,6,6a?,7,7a?,8,9,11, 11a?-deca-hydro-l-hydroxy-2-metlu>xy-6-methyl-10H-dibenzo[(de,g]quinolin-l-ones (16 and 17) was obtained.     

The Synthesis of (±)-11-Deoxydaunomycinone via Regioselective Tandem Diels-Alder Reactions

The 2,5-dimethylidene-3,6-bis[(Z)-(2-nitrophenyl)sulfenylmethylidene]-7-oxabicyclo[2.2.1]heptane ( 13 ) can be used to generate polyfunctional and multicyclic molecules with high regio- and stereoselectivity via two successive Diels-Alder additions using two different dienophiles. This principle has been applied to the synthesis of (±)-11-deoxydaunomycinone ( 7 ), the aglycone of an important antitumor drug. The 2,3-didehydroanisole adds to 13 and gives the monoadduct 14 with high regioselectivity. No trace of bis-adduct is observed. The 1,4-epoxy-1,2,3,4-tetrahydro-5-methoxy-3-methylidene-2-[(Z)-(2-nitrophenyl)sulfenylmethylidene]anthracene ( 15 ) obtained on treating 14 with K₂CO₃ adds to methyl vinyl ketone to give [(1RS, 2SR, 5RS,12RS)-5,12-epoxy-1,2,3,4,5,12-hexahydro-7-methoxy-1-(2-nitrophenyl)sulfenyl-2-naphthacenyl]methyl ketone ( 16 ) with high regio- and stereoselectivity. The acid-catalyzed 7-oxanorbornadiene→phenol rearrangement of 16 is regioselective and gives (5-acetoxy-3,4-dihydro-7-methoxy-2-naphthacenyl) methyl ketone ( 20 ) which was transformed into (±)-7,11-dideoxydaunomycinone ((±)- 24 ), a known precursor of 7 .     

1-(1-甲氧基-1-二茂铁基-3-芳基-丙烷-2-基)-1H-1,2,4-三唑类衍生物的合成及生物活性研究

通过在三唑类活性结构中引入较大空间位阻的二茂铁基设计合成了11个新颖的含二茂铁取代的1H-1,2,4-三唑类化合物, 其结构经元素分析, ¹H NMR谱和单晶X-ray衍射分析得到确证. 初步的生物活性测试表明, 部分化合物具有明显的植物生长调节活性.     

Synthesis of 7-(2-R-pyrimidin-4-yl)- and 7-(2-R-[1,2,4]triazolo[1,5-<Emphasis Type="Italic">a</Emphasis>]pyrimidin-7-yl)-2,2,4,6-tetramethyl-1,2,3,4-tetrahydroquinolines

Cyclization of 3-(dimethylamino)-1-(2,2,4,6-tetramethyl-1,2,3,4-tetrahydroquinolin-7-yl)prop-2-en-1-one with carboximidamides, guanidines, and 1,2,4-triazol-5-amines afforded a number of new 2,2,4,6-tetramethyl-7-(2-R-pyrimidin-4-yl)-1,2,3,4-tetrahydroquinolines and 2,2,4,6-tetramethyl-7-(2-R-[1,2,4]triazolo-[1,5-a]pyrimidin-7-yl)-1,2,3,4-tetrahydroquinolines.     

Synthesis of 7- (or 6-)hydroxy derivatives of 3,3-dimethyl-3,4-dihydroisoquinoline

When treated with cyanoacetic ester in conc. H₂SO₄ 1-(4-hydroxy-3-methoxyphenyl)- and 1-(3-hydroxy-4-methoxyphenyl)-2-methylpropan-1-ol form ethyl 7-hydroxy-6-methoxy-3,3-dimethyl(or 6-hydroxy-7-methoxy- 3,3-dimethyl)-1,2,3,4-tetrahydroisoquinolylidene-1-acetate. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 421-425, March, 2009.