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1.
Reaction of 5-dimethylaminomethylpyrrolo[2,3-b]pyridine methiodide or 5-dimethylaminomethylpyrrolo[2,3-d]pyrimidin-4-one methiodide with 5′-deoxy-5′-S-thioacetyl-N6-formyl-2′,3′-O-isopropylideneadenosine in ethanolic sodium hydroxide solution, followed by deprotection of the resulting thioether in 80% formic acid, afforded 5′-deoxy-5′-(5-pyrrolo[2,3-b]pyridinemethylthio)adenosine or 5′-deoxy-5′-[5-(pyrrolo[2,3-d]pyrimidin-4-one)methylthio]adenosine, respectively. Similarly, the metiodide salt of the iso-gramine analog, 2-amino-6-dimethylaminomethylpyrrolo[2,3-d]pyrimidin-4-one afforded 5′-deoxy-5′-[6-(2-aminopyrrolo[2,3-d]pyrimidin-4-one)methylthio]adenosine.  相似文献   

2.
A series of new base-protected and 5′-O-(4-monomethoxytrityl)- or 5′-O-(4,4′-dimethoxytrityl)-substituted 3′-(2-cyanoethyl diisopropylphosphoramidites) and 3′-[2-(4-nitrophenyl)ethyl diisopropylphosphoramidites] 52 – 66 and 67 – 82 , respectively, are prepared as potential building blocks for oligonucleotide synthesis (see Scheme). Thus, 3′,5′-di-O-acyl- and N 2,3′-O,5′-O-triacyl-2′-deoxyguanosines can easily be converted into the corresponding O6-alkyl derivatives 6 , 8 , 10 , 12 , 14 , and 16 by a Mitsunobu reaction using the appropriate alcohol. Mild hydrolysis removes the acyl groups from the sugar moiety (→ 9 , 11 , 13 , 15 , and 19 (via 18 ), resp.) which can then be tritylated (→ 38 – 42 ) and phosphitylated (→ 57 – 61 ) in the usual manner. N 2-[2-(4-nitrophenyl)ethoxycarbonyl]-substituted and N 2-[2-(4-nitrophenyl)ethoxycarbonyl]-O6-[2-(4-nitrophenyl)ethyl]-substituted 2′-deoxyguanosines 5 and 7 , respectively, are synthesized as new starting materials for tritylation (→ 28 , 35 , and 37 ) and phosphitylation (→ 54 , 56 , 70 , and 78 ). Various O4-alkylthymidines (see 20 – 24 ) are also converted to their 5′-O-dimethoxytrityl derivatives (see 43 – 47) and the corresponding phosphoramidites (see 62 – 66 and 79 – 82 ).  相似文献   

3.
The Common 2′ -deoxypyrimidine and -purine nucleosides, thymidine ( 4 ), O4-[2-(4-nitrophenyl)ethyl]-thymidine ( 17 ), 2′-deoxy-N4-[2-(4-nitrophenyl)ethoxycarbonyl]cytidine ( 26 ), 2′-deoxy-N6-[2-(4-nitrophenyl)-ethoxycarbonyl]adenosine- 39 , and 2′-deoxy-N2-[2-(4-nitrophenyl)(ethoxycarbonyl]-O6-[2–4-nitrophenyl)ethyl]-guanosine ( 52 ) were further protected by the 2-(4-nitrophenyl)ethoxycarbonyl (npeoc) and the 2-(2,4-dinitrophenyl)ethoxycarbonyl (dnpeoc) group at the OH functions of the sugar moiety to form new partially and fully blocked intermediates for nucleoside and nucleotide syntheses. The corresponding 5′-O-monomethoxytrityl derivatives 5 , 18 , 30 , 40 , and 56 were also used as starting material to synthesize some other intermediates which were not obtained by direct acylations. In the ribonucleoside series, the 5′ -O-monomethoxytrityl derivatives 14 , 36 , 49 , and 63 reacted with 2-(4-nitrophenyl) ethyl chloroformate ( 1 ) to the corresponding 2′,3′-bis-carbonates 15 , 37 , 50 , and 64 which were either detriylated to 16 , 38 , 51 , and 65 , respectively, or converted by 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) treatment to the 2′,3′-cyclic carbonates 66 – 69 . The newly synthesized compounds were characterized by elemental analyses and UV and 1H-NMR spectra.  相似文献   

4.
Chroma to graphic Separation and Identification of Diastereomeric Carotinoids with Distant Chiral Centers The high-performance liquid chromatographic separation of diastereomeric C40-carotinoids is described possessing chiral centers which are separated by 18 C-atoms (nonaene system). The method is applied to the separation of the two diastereomers of 6,6′-dihydrorhodoxanthin 1a and 1b (ε,ε-carotene-3,3′-dione) and the six diastereomers of tunaxanlhin (ε,ε-carotene-3,3′-diol; 2a–2f ). Conditions for the separation of lutein [(3R, 3′R, 6′R)-β,ε-carotene-3.3′-diol, 3a ], 3′-epi-lutein [(3R,3′S,6′R)-β, ε-carotene-3,3′-diol, 3b ] and its 13′-cis- ( 3c ) and 13-cis-stereo-isomers( 3d ) are also reported. Identification of the different chromatographic fractions was possible by use of authentic synthetic samples or by 1H-NMR. spectroscopy.  相似文献   

5.
0The bipyridyl-armed tetra-p-(tert-butyl)calix[4]arenes 1 – 5 were synthesized from tetra-p-(tert-butyl)-calix[4]arene A and 6-(bromomethyl)-6′-methyl-2,2′-bipyridine ( B ) by direct base-strength-driven regioselective O-alkylation or by stepwise procedures. Preliminary complexation studies of the ligands 1 – 3 with CuI affording the complexes 6 – 8 are described.  相似文献   

6.
Novel tetracyclic ring systems viz. 3-methyl-1-oxo-12H-1, 2, 4-triazepino[3′,4′:3, 4][1, 2, 4]triazino[5, 6-b]indole ( 4a ) and 3-methyl-5-oxo-12H-1, 2, 4-triazepino[4′,3′:2, 3][1, 2, 4]triazino[5, 6-b]indole ( 5a ), having angular and linear structures respectively, were synthesized by the cyclization of 3-oxobutanoic acid [5H-1, 2, 4-triazino-[5, 6-b]indole-3-yl]hydrazone ( 3a ). However, cyclization of 3b (R = CHa, R1 = R2 = H) afforded the angular product 4b exclusively. Moreover, cyclization of 3c (R = R3 = H, R1 = F) yielded 7-fluoro-1-0xo-10H-1, 3-imidazo[2′,3′:3, 4][1, 2, 4]triazino[5, 6-b]indole ( 6c ) and 7-fluoro-3-oxo-10H-1, 3-imidazo[3′,2′:2, 3][1, 2, 4]triazino-[5, 6-b]indole ( 7c ) instead of the expected triazepinone derivatives. Compound 3d (R = R1 = H, R2 = CF3) also gave an imidazole derivative but only one angular product was obtained. In all these reactions, formation of the angular product involving cyclization at N-4 is favoured. Characterization of these products have been done by elemental analyses, ir, pmr, 19F nmr and mass spectral studies.  相似文献   

7.
The synthesis of the polyhalogenated phenylalanines Phe(3′,4′,5′-Br3) ( 3 ), Phe(3′,5′-Br2-4′-Cl) ( 4 ) and DL -Phe (2′,3′,4′,5′,6′-Br5) ( 9 ) is described. The trihalogenated phenylalanines 3 and 4 are obtained stereospecifically from Phe(4′-NH2) by electrophilic bromination followed by Sandmeyer reaction. The most hydrophobic amino acid 9 is synthesized from pentabromobenzyl bromide and a glycine analogue by phase-transfer catalysis. With the amino acids 4, 9 , Phe(4′-I) and D -Phe, analogues of [1-sarcosin]angiotensin II ([Sar1]AT) are produced for structure-activity studies and tritium incorporation. The diastereomeric pentabromo peptides L - and D - 13 are separated by HPLC. and identified by catalytic dehalogenation and comparison to [Sar1]AT ( 10 ) and [Sar1, D -Phe8]AT ( 14 ).  相似文献   

8.
The pyrazolo[5′, 1′:3, 4][1, 2, 4]triazino[5, 6-d]pyrimidines 5a-c, 6 were synthesized from the pyrazolo[5, 1-c]-[1, 2, 4]triazines 1a, c and the ring carbon signals of 5a-c, 6 were assigned by the aid of coupling constant [J( 13 C-1H)] data.  相似文献   

9.
Blue needle—shaped crystals of [Cu(bpy)(H2O)2(C4H4O4)]· 2H2O were obtained by slow evaporation of a methanolic aqueous solution containing a fresh Cu(C4H4O4)· 2H2O precipitate, 4, 4′—bipyridine, and ammonia. Within the complex, the six—coordinated Cu atoms are linked by bis—monodentate gauche succinate anions into chains propagating helically around the [001] axis. The chains are interconnected by 4, 4′—bipyridine ligands into a 3D framework with the crystal H2O molecules located in the channels along the [100], [010] and [110] directions. The Cu2+ ions are in distorted octahedral coordination of two nitrogen and four oxygen atoms (equatorial bonds: Cu—N 1.986(5), 2.015(5)Å; Cu—O 1.950(6), 1.954(6)Å; axial bonds Cu—O: 2.524(9), 2.539(8)Å). Furthermore, the thermal and magnetic behavior of the compound will be discussed. Crystal data: hexagonal, P61 (no. 169), a = 11.066(2)Å, c = 24.965(5)Å, V = 2647.5(8)Å3, Z = 6, R = 0.0528 and wR2 = 0.1103 for 1426 observed reflections (Fo2 > 2σ(Fo2)) out of 2170 unique reflections.  相似文献   

10.
A variety of 3″,5″‐diaryl‐3″H,4′H‐dispiro[cyclohexane‐1,2′‐chromene‐3′,2″‐[1,3,4]thiadiazol]‐4′‐ones 3a‐c were synthesized regioselectively through the reaction of 4′H,5H‐trispiro[cyclohexane‐1,2′‐chromene‐3′,2″‐[1,3,4]oxadithiino[5,6‐c]chromene‐5″,1″′‐cyclohexan]‐4′‐one ( 1 ) with nitrilimines (generated in situ via triethylamine dehydrohalogenation of the corresponding hydrazonoyl chlorides 2a‐c ) in refluxing dry toluene. Single crystal X‐ray diffraction studies of 3a,b add support for the established structure. Similarly, 3′,5′‐diaryl‐2,2‐dimethyl‐3′H,4H‐spiro[chromene‐3,2′‐[1,3,4]thiadiazol]‐4‐ones 5a‐c were obtained in a regioselective manner through the reaction of 2,2,5′,5′‐tetramethyl‐4H,5′H‐spiro[chromene‐3,2′‐[1,3,4]oxadithiino[5,6‐c]chromen]‐4‐one ( 4a ) with nitrilimines under similar reaction conditions. On the other hand, reaction of 2,5′‐diethyl‐2,5′‐dimethyl‐4H,5′H‐spiro[chromene‐3,2′‐[1,3,4]oxadithiino‐[5,6‐c]chromen]‐4‐one ( 4b ) with nitrilimines in refluxing dry toluene afforded the corresponding 3′,5′‐diaryl‐2‐ethyl‐2‐methyl‐3′H,4H‐spiro[chromene‐3,2′‐[1,3,4]thiadiazol]‐4‐ones 5d‐f as two unisolable diastereoisomeric forms.  相似文献   

11.
Crystal and solution structures of the [PdII3-allyl)] and of the [PdII3-1,3-diphenylallyl)] complexes, 4 and 5 , respectively, with (4S)-4-benzyl-2-[2′-(diphenylphosphino)phenyl]-4,5-dihydrooxazole ( 3 ) were determined by X-ray crystallography and 2D-NMR spectroscopy. Complex 4 proved to be disordered with both diastereoisomeric complexes in the crystal. The results of X-ray and NMR experiments demonstrate a good agreement between solution and solid-state equilibria of the two isomers. A comparison with dichloro{(4S)-2-[2′-(diphenylphosphino)phenyl]-4,5-dihydro-4-phenyloxazole-P,N}zinc(II) ( 2b ) shows a surprising conformational stability of the coordinated phosphinooxazole ligand 3 .  相似文献   

12.
The application of the improved phosphoramidite strategy for the synthese of oligonucleotides using β-eliminating protecting groups to phospholipid chemistry offers the possibility to synthesize phospholipid conjugates of AZT ( 6 ) and cordycepin. The synthesis of 3′-azido-3′-deoxythymidine ( 6 ) was achieved by a new isolation procedure without chromatographic purification steps in an overall yield of 50%. Protected cordycepin ( = 3′-de-oxyadenosine) derivatives, the N6,2′-bis[2-(4-nitrophenyl)ethoxycarbonyl]cordycepin ( 12 ) and the N6,5′-bis[2-(4-nitrophenyl)ethoxycarbonyl]cordycepin ( 13 ) wre prepared by known methods and direct acylation of N6-[2-(4-nitrophenyl)ethoxycarbonyl]cordycepin ( 9 ), respectively. These protected nucleosides and the 3′-azido-3′-de-oxythymidine ( 6 ) reacted with newly synthesized and properly characterized lipid-phosphoramidites 21–25 , catalyzed by 1H-tetrazole, to the corresponding nucleoside-phospholipid conjugates 26–38 in high yield. The deprotection was accomplished via β-elimination with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in aprotic solvents to give analytically pure nucleoside-phospholipid diesters 39–51 as triethylammonium or sodium salts. The newly synthesized compounds were characterized by elemental analyses and UV and 1H-NMR spectra.  相似文献   

13.
Abstract— The photoproducts of the dinucleoside monophosphates, dTpdT, dTpdC and dTpdU, have been purified by high performance liquid chromatography and characterized by UV absorption spectroscopy, fast atom bombardment mass spectrometry and by secondary thermal and photoreactions. Four types of photoproducts were analyzed: (1) cyclobutane dimers including cis-syn isomers and two diastereomers of the trans-syn isomers; (2) 6-4 photoadducts and the corresponding Dewar valence isomers; (3) photohydrates comprising two diastereomers and (4) a new photoproduct resembling nucleobase amine adducts, which occurs only for dTpdC. The quantum yields of formation of these photoproducts and for some secondary photoreactions were measured by kinetic analysis of the photoproduct yield as a function of photon fluence. These results indicate that cis-syn cyclobutane dimers are the photoproducts formed with highest efficiency with dT[p]dC dimers being formed with 50–75% the efficiency of dT[p]dT dimers. The 6-4 photoadducts are formed with 5–10% the efficiency of cis-syn cyclobutane dimers and the 6-4 photoadduct of dTpdC is formed two to three times more efficiently than that of dTpdT. Photohydrates are also formed efficiently due to an equilibrium between stacked and unstacked complexes of the dinucleoside monophosphates. It is shown that three of these photoproducts, namely the cyclobutane dimers of dTpdC, the 6-4 photoadducts and the possible nucleobase amine adduct, undergo photolysis in the UV-B region resulting in either photoreversion or secondary photoreaction.  相似文献   

14.
Asymmetric Michael-Additions Practically Completely Diastereo- and Enantloselective Alkylations of the Enamine from Cyclohexanone and Prolinyl Methyl Ether by ω-Nitrostyrenes to Give u2-(1′-Aryl-2′-nitroethyl)cyclohexanones When the enamine (S)-N-(1′cyclohexenyl)-2-methoxymethyl-pyrrolidine is added to 2-aryl-l-nitroethylenes, only one of the four possible enantiomerically pure diastereomers is formed. Hydrolysis of the crude primary products furnishes α-alkylated cyclohexanones of > 90% e. e. ( 3 , Scheme 3). Their (2S,1′R)-configuration was deduced by chemical correlation with l-cyclohexyl-l-phenyl-ethane and from an X-ray crystal structure analysis of (?)-(2R,3S,6′R1,l″S′)-3-methyl-N-[6′-(2″-nitro-l″-phenylethyl)-l′-cyclohexenyl]-2-phenylmorpholine ( lla , Scheme 5 and Fig. 2). - The relative topicity of reactant approach with the prolinol derivative (see II ) is specified as lkul-l,4. The steric course and the mechanism of the reaction are discussed.  相似文献   

15.
TiO2 nanoparticles supported on carbon nanotubes (TiO2-CNTs) as an efficient heterogeneous catalyst was used for the synthesis of spiro[3,4′]1,3-dihydro-2H-indol-2-one-2′-amino-5′-oxo-4'H,5'H-pyrano[3′,2′-c]chromen-3′-yl cyanides and spiro[3,8′]1,3-dihydro-2H-indol-2-one-6′-amino-8'H-[1′,3′]dioxolo[4′,5′-g]chromen-7′-yl cyanides via the cyclocondensation reaction of isatins with malononitrile and 4-hydroxycoumarin or 3,4-methylenedioxyphenol in aqueous media at room temperature. This reaction offers several sustainable and economic benefits such as high yields of products, convenient operation, and use of non-toxic catalyst in water media.  相似文献   

16.
The 13C NMR spectra of a number of pyridazine derivatives have been recorded in DMSO-d6 solution and analysed. Examination of the most diagnostic resonances, with particular emphasis on those arising from the pyridazine ring system, enabled the ready establishment of the presence of a ring-chain tautomerism in 5-(o-aminophenylcarbamoyl)pyridazine-4-carboxylic acid, methyl 5-(o-aminophenylcarbamoyl)pyridazine-4-carboxylate, 5-(o-aminophenylcarbamoyl)-3,6,-dimethylpyridazine-4-carboxylic acid and 5-(2-amino-1,2-dicyanovinylenecarbamoyl)pyridazine-4-carboxylic acid. This gave rise to 3′,4′-dihydro-3′-oxospiro[pyridazine-5(2H),2′(1H)-quinoxaline]-4-carboxylic acid, methyl 3′,4′-dihydro-3′oxospiro[pyridazine-5(2H),2′(1′H)-quinoxaline]-4-carboxylate, 3′,4′-dihydro-3′-oxo-3,6-dimethylspiro[pyridazine-5(2H), 2′(1′H)-quinoxaline]-4-carboxylic acid and 5-oxo-2,3-dicyano-1,4,8,9-tetraazaspiro[5.5]undeca-2,7,10-triene-11-carboxylic acid, respectively.  相似文献   

17.
The Zn complexes bis(acetylacetonato‐κ2O,O′)bis{4′‐[4‐(methylsulfanyl)phenyl]‐4,2′:6′,4′′‐terpyridine‐κN1}zinc(II), [Zn(C5H7O2)2(C22H17N3S)2], (I), and {μ‐4′‐[4‐(methylsulfanyl)phenyl]‐4,2′:6′,4′′‐terpyridine‐κ2N1:N1′′}bis[bis(acetylacetonato‐κ2O,O′)zinc(II)], [Zn2(C5H7O2)4(C22H17N3S)], (II), are discrete entities with different nuclearities. Compound (I) consists of two centrosymmetrically related monodentate 4′‐[4‐(methylsulfanyl)phenyl]‐4,2′:6′,4′′‐terpyridine (L1) ligands binding to one ZnII atom sitting on an inversion centre and two centrosymmetrically related chelating acetylacetonate (acac) groups which bind via carbonyl O‐atom donors, giving an N2O4 octahedral environment for ZnII. Compound (II), however, consists of a bis‐monodentate L1 ligand bridging two ZnII atoms from two different Zn(acac)2 fragments. Intra‐ and intermolecular interactions are weak, mainly of the C—H...π and π–π types, mediating similar layered structures. In contrast to related structures in the literature, sulfur‐mediated nonbonding interactions in (II) do not seem to have any significant influence on the supramolecular structure.  相似文献   

18.
The 4,4′,6,6′-tetrasubstituted 2,2′-alkylidenebis(phenols) 1 reacted with CISCOI to give spiro[1,3-benzoxathiepin-4(5H), 1′-cyclohexa[2,4]diene]-2,2′-diones 4 , together with cyclic carbonates 5 . The structures of the products were elucidated mainly by 13C-NMR and 1H-NMR spectroscopy.  相似文献   

19.
A series of 7,12-dihydropyrimido[1′2′:1,2]pyrido[3,4-b]mdole-4(6H)-ones was prepared by Fischer indolization of 9-arylhydrazono-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrirmdin-4-ones. Quantum chemical calculations (ab initio and AM1) indicate that position 3 of 7,12-dihydropyrimido[1′,2′:1,2]pyrido-[3,4-b]indole-4(6H)-one can be involved in electrophilic substitutions, while position 2 is sensitive towards nucleophilic attack. Bromination of 6-methyl-7,12-tetrahydropyrimido[1′,2′:1,2]pyrido-[3,4-b]indol-4(6H)-one 16 with bromine afforded 3-bromo derivative 25 , which was reacted with cyclic amines to give 2-ammo-7,12-dihydropyrirmdo[1′2′:1,2]pyrido[3,4-b]indol-4(6H)-ones 26–30 in an addition-elimination reaction. Vielsmeier-Haack formylation of compound 16 gave 12-formyl 31 and 3,12-diformyl 32 derivatives (an N-formyl-1-deaza derivative of nauclefidine alkaloid 34 ) at 60° and 100°, respectively. 3,12-Diformyl compound 32 was oxidized to 3-carboxyl derivative 33 with potassium permanganate. The quaternary salt 35 , obtained from compound 16 with dimethyl sulfate, suffered a ring opening on the action of aqueous sodium hydroxide. The new compounds have been characterized by elemental analyses uv, 1H nmr and in some cases by 13C ruler, CD spectra and X-ray investigations.  相似文献   

20.
The convergent syntheses of 3-deazapurine 2′-deoxy-β-D -ribonucleosides and 2′,3′-dideoxy-D -ribonucleosides, including 3-deaza-2′-deoxyadenosine ( 1a ) and 3-deaza-2′,3′-dideoxyadenosine ( 1b ) is described. The 4-chloro-lH-imidazo[4,5-c]pyridinyl anion derived from 5 was reacted with either 2′-deoxyhalogenose 6 or 2′,3′-dideoxyhalogenose 10 yielding two regioisomeric (N1 and N3) glycosylation products. They were deprotected and converted into 4-substituted imidazo[4,5-c]pyridine 2′-deoxy-β-D -ribonucleosides and 2′,3′-dideoxy-D -ribonucleosides. Compounds 1a and 1b proved to be more stable against proton-catalyzed N-glycosylic bond hydrolysis than the parent purine nucleosides and were not deaminated by adenosine deaminase.  相似文献   

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