Synthesis of 5(6)-(1-adamantyl)benzimidazoles

New 2-alkyl and 2-aryl derivatives of 5(6)-(1-adamantyl)benzimidazole have been synthesized. Certain reactions of N-alkylation and N-acylation of these compounds have been studied.     

Synthesis and reactions of some 5(6)-(1-adamantyl)benzimidazoles

4-(1-Adamantyl)-1,2-diaminobenzene, previously unreported in the literature, has been prepared and a novel series of 5(6)-(1-adamantyl)benzimidazole derivatives synthesized. Nitration, hydrogenation, and side chain reactions have been carried out. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1172–1182, August, 2008.     

New synthesis of 4-(1-adamantyl)-2-aryl-1,3-thiazoles from 4-(1-adamantyl)-1,2,3-thiadiazole

Treatment of 4-(1-adamantyl)-1,2,3-thiadiazole with potassium tert-butoxide generated potassium 2-(1-adamantyl)ethynethiolate which reacted with aromatic carboxylic acid chlorides to give unstable S-[2-(1-adamantyl)ethynyl] arenecarbothioates whose acid hydrolysis afforded S-[2-(1-adamantyl)-2-oxoethyl] arenecarbothioates. The latter reacted with ammonium acetate in acetic acid yielding 4-(1-adamantyl)-2-aryl-1,3-thiadiazoles. Reactions of 4-(1-adamantyl)-2-(4-chloro-3-nitrophenyl)-1,3-thiadiazole with cyclic secondary amines gave the corresponding products of nucleophilic replacement of the chlorine atom in the aromatic ring.     

Synthesis and structure of bis[1-(1-adamantyl)-4,4,4-trifluorobutane-2,4-dionato]copper

Previously unknown 1-(1-adamantyl)-4,4,4-trifluorobutane-2,4-dione and its copper complex, bis [1-(1-adamantyl)-4,4,4-trifluorobutane-2,4-dionato]copper, were synthesized. The ¹H NMR, IR, and ESR spectra and X-ray diffraction patterns of the synthesized compounds were obtained. Volatilily and thermal stability of the copper complex were studied by thermogravimetric analysis and differential scanning calorimetry.     

Synthesis of amino acid derivatives of 4-(1-adamantyl)benzoic acid obtained by transition metal ion catalyzed oxidation of 4-(1-adamantyl)toluene

An efficient synthesis of 4-(1-adamantyl)benzoic acid based on transition metal ion catalyzed oxidation of 4-(1-adamantyl)toluene has been developed. As a catalytic system, cobalt-manganese bromide with addition of manganese acetate was used. A series of amino acid derivatives of 4-(1-adamantyl)benzoic acid was then synthesized and characterized. These derivatives are novel intermediates potentially useful in the design of therapeutically active peptidomimetics with improved pharmacokinetic and pharmacodynamic parameters.     

Synthesis and reactivity of new l-(1-adamantyl)pyrazoles

Using 1-adamantylhydrazine as starting material, a series of 1-(1-adamantyl)pyrazoles has been prepared. Electrophilic reactivity (bromination and nitration) and nucleophilic reactivity (quaternarization) have been studied. Proton nuclear magnetic resonance spectra of all the new compounds are recorded.     

Halogenation and nitrosation of 2-(1-adamantyl)indolizine

Russian Journal of Organic Chemistry -     

Alkali metal 2-(1-adamantyl)ethynethiolates: Synthesis and reactions with electrophilic reagents

Treatment of ethyl 2-[1-(1-admantyl)ethylidene]hydrazine-1-carboxylate with thionyl chloride gave 4-(1-adamantyl)-1,2,3-thiadiazole which readily underwent decomposition by the action of strong bases with formation of alkali metal 2-(1-adamantyl)ethynethiolates. The latter were brought into reactions with proton donors and benzyl halides.     

Synthesis of <Emphasis Type="Italic">N</Emphasis>-[4-hydroxy(alkoxy,acyloxy)-3-alkoxy-benzylidene]-1-(1-adamantyl)ethanamines from 1-(1-adamantyl)ethanamine hydrochloride (Rimantadine)

Reactions of 1-(1-adamantyl)ethanamine with vanillin, vanillal, veratraldehyde, 3-ethoxy-4-methoxybenzaldehyde, and 4-formyl-2-methoxy(ethoxy)phenyl esters gave previously unknown Schiff bases containing an adamantane fragment.     

Synthesis,characterization, and structures of 1-(9-Fluorenyl)-germatrane and 1-(Phenylacetylenyl)germatrane

Syntheses of the title compounds, viz. N(CH₂CH₂O)₃GeY ( 2 Y?Fluorenyl; 4 Y?PhC?C) by the reaction of X₃GeY ( 1 Y?Fluorenyl, X?Br; 5 Y?PhC?C, X?Cl) with N(CH₂CH₂OSnR₃)₃ ( 3 R?Et; 6 R?Bu) are reported including the preparation of the new compound 1 . Identity and structures were established by elemental analyses, ¹H and ¹³C NMR spectroscopy. 2 and 4 were characterized by mass spectrometry. Single crystal structures of 1 , 2 and 4 were determined by X-ray diffraction methods.     

Synthesis of functionalized 5-(3-R-1-adamantyl)uracils and related compounds

Efficient synthetic approaches to functionalized 5-(3-R-1-adamantyl)uracils and related compounds (R=OH, COOH, NH₂, etc.) are described. The selective hydroxylation of the adamantane tertiary C-H bonds in 5-(1-adamantyl)uracils with H₂SO₄ in trifluoroacetic anhydride is used as the key step. Subsequent electrophilic reactions of 5-(3-hydroxy-1-adamantyl)uracils with N- and C-nucleophiles in CF₃COOH, H₂SO₄ or H₂SO₄/AcOH media yielded derivatives with amide, amino, aryl, carboxy and thiourea groups in the adamantane core. The preliminary evaluation of the antiviral activity revealed that some of the synthesized species display moderate antiviral activity against HSV-1 (SI∼20) in Vero cells.