7‐Vinyl‐8‐aza‐7‐de­aza‐2′‐deoxy­adenosine monohydrate

In the title compound, 4‐amino‐1‐(2‐deoxy‐β‐d ‐eythro‐pento­furan­osyl)‐3‐vinyl‐1H‐pyrazolo­[3,4‐d]­pyrimidine monohydrate, C₁₂H₁₅N₅O₃·H₂O, the conformation of the gly­cosyl bond is anti. The furan­ose moiety is in an S conformation with an unsymmetrical twist, and the conformation at the exocyclic C—C(OH) bond is +sc (gauche, gauche). The vinyl side chain is bent out of the heterocyclic ring plane by 147.5 (5)°. The three‐dimensional packing is stabilized by O—H·O, O—H·N and N—H·O hydrogen bonds.     

7‐Iodo‐8‐aza‐7‐deaza‐2′‐deoxy­adenosine and 7‐bromo‐8‐aza‐7‐deaza‐2′‐deoxyadenosine

The isomorphous structures of the title molecules, 4‐amino‐1‐(2‐deoxy‐β‐d ‐erythro‐pento­furan­osyl)‐3‐iodo‐1H‐pyrazolo‐[3,4‐d]pyrimidine, (I), C₁₀H₁₂IN₅O₃, and 4‐amino‐3‐bromo‐1‐(2‐deoxy‐β‐d ‐erythro‐pento­furan­osyl)‐1H‐pyrazolo[3,4‐d]­pyrimidine, (II), C₁₀H₁₂BrN₅O₃, have been determined. The sugar puckering of both compounds is C1′‐endo (^1′E). The N‐­glycosidic bond torsion angle χ¹ is in the high‐anti range [?73.2 (4)° for (I) and ?74.1 (4)° for (II)] and the crystal structure is stabilized by hydrogen bonds.     

6‐Aza‐2′‐deoxy­uridine and N3‐anisoyl‐6‐aza‐2′‐deoxy­uridine

In 2‐(2‐deoxy‐β‐d ‐erythro‐pentofuranosyl)‐1,2,4‐triazine‐3,5(2H,4H)‐dione (6‐aza‐2′‐deoxy­uridine), C₈H₁₁N₃O₅, (I), the conformation of the glycosylic bond is between anti and high‐anti [χ = −94.0 (3)°], whereas the derivative 2‐(2‐deoxy‐β‐d ‐erythro‐pentofuranosyl)‐N⁴‐(2‐methoxy­benzoyl)‐1,2,4‐triazine‐3,5(2H,4H)‐dione (N³‐anisoyl‐6‐aza‐2′‐deoxy­uridine), C₁₆H₁₇N₃O₇, (II), displays a high‐anti conformation [χ = −86.4 (3)°]. The furanosyl moiety in (I) adopts the S‐type sugar pucker (²T₃), with P = 188.1 (2)° and τ_m = 40.3 (2)°, while the sugar pucker in (II) is N (³T₄), with P = 36.1 (3)° and τ_m = 33.5 (2)°. The crystal structures of (I) and (II) are stabilized by inter­molecular N—H⋯O and O—H⋯O inter­actions.     

5‐Methyl‐6‐aza‐2′‐deoxy­isocytidine

In the title compound, 3‐amino‐2‐(2‐deoxy‐β‐d ‐erythro‐pento­furan­osyl)‐6‐methyl‐1,2,4‐triazin‐5(2H)‐one, C₉H₁₄N₄O₄, the conformation of the N‐glycosidic bond is high‐anti and the 2‐deoxy­ribo­furan­osyl moiety adopts a North sugar pucker (²T₃). The orientation of the exocyclic C—C bond between the –CH₂OH group and the five‐membered ring is ap (gauche, trans). The crystal packing is such that the nucleobases lie parallel to the ac plane; the planes are connected via hydrogen bonds involving the five‐membered ring.     

7‐Deaza‐2′‐deoxy­guanosine

In the title compound, 2‐amino‐7‐(2‐deoxy‐β‐d ‐erythro‐pentofuran­osyl)‐3,7‐dihydro­pyrrolo[2,3‐d]pyrimidin‐4‐one, C₁₁H₁₄N₄O₄, the N‐glycosylic bond torsion angle, χ, is anti [−106.5 (3)°]. The 2′‐deoxy­ribofuran­osyl moiety adopts the ³T₄ (N‐type) conformation, with P = 39.1° and τ_m = 40.3°. The conformation around the exocyclic C—C bond is ap (trans), with a torsion angle, γ, of −173.8 (3)°. The nucleoside forms a hydrogen‐bonded network, leading to a close‐packed multiple‐layer structure with a head‐to‐head arrangement of the bases. The nucleobase interplanar O=C—C⋯NH₂ distance is 3.441 (1) Å.     

2‐Amino‐7‐chloro‐2′‐deoxy­tubercidin

In 4‐chloro‐7‐(2‐de­oxy‐β‐d ‐erythro‐pento­furanos­yl)‐7H‐pyr­rolo­[2,3‐d]­pyrimidine‐2,4‐diamine, C₁₁H₁₄ClN₅O₃, the conformation of the N‐glycosylic bond is between anti and high‐anti [χ = −102.5 (6)°]. The 2′‐deoxy­ribofuranosyl unit adopts the C3′‐endo‐C4′‐exo (³T₄) sugar pucker (N‐type) with P = 19.6° and τ_m = 32.9° [terminology: Saenger (1989). Landolt‐Börnstein New Series, Vol. 1, Nucleic Acids, Subvol. a, edited by O. Madelung, pp. 1–21. Berlin: Springer‐Verlag]. The orientation of the exocyclic C4′—C5′ bond is +ap (trans) with a torsion angle γ = 171.5 (4)°. The compound forms a three‐dimensional network that is stabilized by four inter­molecular hydrogen bonds (N—H⋯O and O—H⋯N) and one intra­molecular hydrogen bond (N—H⋯Cl).     

6‐Aza‐2′‐deoxy‐2′‐arabino­fluoro­uridine,a 2′‐deoxy­ribonucleoside with an N‐sugar conformation in the solid state and in solution

In the title compound, 2‐(2‐deoxy‐2‐fluoro‐β‐d ‐arabino­fur­anosyl)‐1,2,4‐triazine‐3,5(2H,4H)‐dione, C₈H₁₀FN₃O₅, the torsion angle of the N‐gly­cosylic bond is anti [χ = −125.37 (13)°]. The furan­ose moiety adopts the N‐type sugar pucker (³T₂), with P = 359.2° and τ_m = 31.4°. The conformation around the C4′—C5′ bond is antiperiplanar (trans), with a torsion angle γ of 177.00 (11)°. A network is formed via hydrogen bonds from the nucleobases to the sugar residues, as well as through hydrogen bonds between the sugar moieties.     

N8‐(2′‐O‐Methyl­ribofuranos­yl)‐8‐aza‐7‐deaza­adenine monohydrate

In the title compound, 4‐amino‐2‐(2‐O‐methyl‐β‐d ‐ribofuranos­yl)‐2H‐pyrazolo[3,4‐d]pyrimidine monohydrate, C₁₁H₁₅N₅O₄·H₂O, the conformation of the N‐glycosylic bond is syn [χ = 20.1 (2)°]. The ribofuran­ose moiety shows a C3′‐endo (³T₂) sugar puckering (N‐type sugar), and the conformation at the exocyclic C4′—C5′ bond is −ap (trans). The nucleobases are stacked head‐to‐head. The three‐dimensional packing of the crystal structure is stabilized by hydrogen bonds between the 2′‐O‐methyl­ribonucleosides and the solvent mol­ecules.     

2′,3′‐Dide­hydro‐3′‐deoxy­thymidine N‐methyl‐2‐pyrrolidone solvate (D4T·NMPO)

The title compound, 1‐(2′,3′‐di­deoxy‐β‐d ‐glycero‐pent‐2‐eno­furan­osyl)­thymine 1‐methyl‐2‐pyrrolidone solvate, C₁₀H₁₂N₂O₄·­C₅H₉NO, is an NMPO solvate of the anti‐AIDS agent D4T. In its crystal structure, both the pyrimidine and the furan­ose rings are planar and approximately perpendicular [82.1 (4)°]. The value of the torsion angle defining the orientation of the thymine with respect to the joined furane, χ = ?100.8 (4)°, and that of the torsion angle giving the orientation of the hydroxyl group linked to the furane ring, γ = 52.9 (5)°, show that the gly­cosyl­ic link adopts the so‐called high‐anti conformation and the 5′‐hydroxyl group is in the +sc position. The NMPO solvate is linked to the nucleoside through a fairly strong hydrogen bond.     

7‐De­aza‐2′‐deoxy‐7‐propynyl­guanosine

The title compound, C₁₄H₁₆N₄O₄, adopts the anti conformation at the gly­cosylic bond [χ−117.1 (5)°]. The sugar pucker of the 2′‐deoxy­ribo­furan­osyl moiety is C2′‐endo–C3′‐exo, ²T₃ (S‐type). The orientation of the exocyclic C4′—C5′ bond is +sc (gauche). The propynyl group is linear and coplanar with the nucleobase moiety. The structure of the compound is stabilized by several hydrogen bonds (N—H⋯O and O—H⋯O), leading to the formation of a multi‐layered network. The nucleobases, as well as the propynyl groups, are stacked. This stacking might cause the extraordinary stability of DNA duplexes containing this compound.     

The α‐d anomer of 5‐aza‐7‐deaza‐2′‐deoxyguanosine

In the monohydrate of 2‐amino‐8‐(2‐deoxy‐α‐d ‐erythro‐pento­furan­osyl)‐8H‐imidazo­[1,2‐a]­[1,3,5]­triazin‐4‐one, C₁₀H₁₃N₅O₄·H₂O, denoted (I) or αZ_d, the conformation of the N‐gly­cosyl­ic bond is in the high‐anti range [χ = 87.5 (3)°]. The 2′‐deoxy­ribo­furan­ose moiety adopts a C2′‐endo,C3′‐exo(^2′T_3′) sugar puckering (S‐type sugar) and the conformation at the C4′—C5′ bond is ?sc (trans).     

Ultra‐fast adenosine 5′‐triphosphate,adenosine 5′‐diphosphate and adenosine 5′‐monophosphate detection by pressure‐assisted capillary electrophoresis UV detection

Herein, we report a new CE method to measure adenine nucleotides adenosine 5′‐triphosphate, adenosine 5′‐diphosphate, and adenosine 5′‐monophosphate in red blood cells. For this purpose, 20 mmol/L sodium acetate buffer at pH 3.80 was used as running electrolyte, and the separation was performed by the simultaneous application of a CE voltage of 25 kV and an overimposed pressure of 0.2 psi from inlet to outlet. A rapid separation of these analytes in less than 1.5 min was obtained with a good reproducibility for intra‐ and inter‐assay (CV<4 and 8%, respectively) and an excellent analytical recovery (from 98.3 to 99%). The applicability of our method was proved by measuring adenine nucleotides in red blood cells.     

A locked derivative of 8‐aza‐7‐deazaadenosine

The title compound [systematic name: (1S,3S,4R,7S)‐3‐(4‐amino‐1H‐pyrazolo[3,4‐d]pyrimidin‐1‐yl)‐1‐hydroxymethyl‐2,5‐dioxabicyclo[2.2.1]heptan‐7‐ol], C₁₁H₁₃N₅O₄, belongs to a family of nucleosides with modifications in both the sugar and nucleobase moieties: these modifications are known to increase the thermodynamic stability of DNA and RNA duplexes. There are two symmetry‐independent molecules in the asymmetric unit that differ significantly in conformation, and both exhibit a high‐anti conformation about the N‐glycosidic bond, with χ torsion angles of −85.4 (3) and −87.4 (3)°. The sugar C atom attached to the nucleobase N atom is −0.201 (4) and 0.209 (4) Å from the 8‐aza‐7‐deazaadenine skeleton plane in the two molecules. The molecules are assembled into layers via hydrogen bonds and π–π stacking interactions between the modified nucleobases.     

(±)‐6‐tert‐Butyl‐8‐hydroxymethyl‐2‐­phenyl‐4H‐1,3‐benzodioxin and 2,2,2′,2′,6,6′‐hexamethyl‐8,8′‐methylenebis(4H‐1,3‐benzodioxin)

Two compounds containing 1,3‐benzodioxin groups are reported, namely (±)‐6‐tert‐butyl‐8‐hydroxy­methyl‐2‐phenyl‐4H‐1,3‐benzodioxin, C₁₉H₂₂O₃, (I), and 2,2,2′,2′,6,6′‐hexamethyl‐8,8′‐methyl­enebis(4H‐1,3‐benzodioxin), C₂₃H₂₈O₄, (II).The hydroxy groups of neighbouring mol­ecules in (I) are hydrogen bonded to each other, giving rise to double‐row chains. The mol­ecule in (II) adopts a `butterfly' conformation, with the O atoms in distal positions. In both compounds, the dioxin rings are in distorted half‐chair conformations.     

8‐Aza‐7‐deaza‐2′‐de­oxy‐2‐(methyl­sulfan­yl)adenosine

In the title compound, 4‐amino‐1‐(2‐de­oxy‐β‐d ‐erythro‐pentofuranos­yl)‐6‐methyl­sulfanyl‐1H‐pyrazolo[3,4‐d]pyrimidine, C₁₁H₁₆N₅O₃S, the conformation of the glycosidic bond is between anti and high anti. The 2′‐deoxy­ribofuranosyl moiety adopts the C3′‐exo–C4′‐endo conformation (₃T⁴, S‐type sugar pucker), and the conformation at the exocyclic C—C bond is +sc (+gauche). The exocyclic 6‐amine group and the 2‐methyl­sulfanyl group lie on different sides of the heterocyclic ring system. The mol­ecules form a three‐dimensional hydrogen‐bonded network that is stabilized by O—H⋯N, N—H⋯O and C—H⋯O hydrogen bonds.     

A Novel,One‐Pot Four‐Component Route to 2′‐Thioxo‐2′,3′‐dihydrospiro[indole‐3,6′‐[1,3]thiazin]‐2‐one Derivatives

An efficient route to 2′,3′‐dihydro‐2′‐thioxospiro[indole‐3,6′‐[1,3]thiazin]‐2(1H)‐one derivatives is described. It involves the reaction of isatine, 1‐phenyl‐2‐(1,1,1‐triphenyl‐λ⁵‐phosphanylidene)ethan‐1‐one, and different amines in the presence of CS₂ in dry MeOH at reflux (Scheme 1). The alkyl carbamodithioate, which results from the addition of the amine to CS₂, is added to the α,β‐unsaturated ketone, resulting from the reaction between 1‐phenyl‐2‐(1,1,1‐triphenyl‐λ⁵‐phosphanylidene)ethan‐1‐one and isatine, to produce the 3′‐alkyl‐2′,3′‐dihydro‐4′‐phenyl‐2′‐thioxospiro[indole‐3,6′‐[1,3]thiazin]‐2(1H)‐one derivatives in excellent yields (Scheme 2). Their structures were corroborated spectroscopically (IR, ¹H‐ and ¹³C‐NMR, and EI‐MS) and by elemental analyses.     

2′‐Hydroxy‐4′′‐dimethylaminochalcone

The title compound, 3‐[4‐(di­methyl­amino)­phenyl]‐1‐(2‐hydroxy­phenyl)­prop‐2‐en‐1‐one, C₁₇H₁₇NO₂, is a chalcone derivative substituted by 2′‐hydroxyl and 4′′‐di­methyl­amino groups. The crystal structure indicates that the aniline and hydroxy­phenyl groups are nearly coplanar, with a dihedral angle of 10.32 (16)° between their phenyl rings. The molecular planarity of this substituted chalcone is strongly affected by the 2′‐hydroxyl group.     

卜啉与1,2-(1-吖啶-10’-基-2-氮-2-甲基-环丙-1,3-基)富勒烯非共价体的合成与表征

1,2-（1-Acridin-10＇-yl-2-aza-2-methylprop-1,3-ylene）fullerene was synthesized firstly and characterized by UV-Vis, ^1H NMR, ^13C NMR and electrospray ionization mass spectroscopy, which is capable of forming a stable complex with zinc tetraphenylporphyrin via the axial ligation. The steady state fluorescence studies show efficient quenching of the zinc tetraphenylporphyrin emission upon axial coordination of acridine attached to C60.     

Synthesis and photophysical properties of 2,5,8,11‐tetrakis(5‐hexylthiophen‐2‐yl)tetrathieno[2,3‐a:3′,2′‐c:2′′,3′′‐f:3′′′,2′′′‐h]naphthalene

The title compound, C₅₈H₆₄S₈, has been prepared by Pd‐catalysed direct C—H arylation of tetrathienonaphthalene (TTN) with 5‐hexyl‐2‐iodothiophene and recrystallized by slow evaporation from dichloromethane. The crystal structure shows a completely planar geometry of the TTN core, crystallizing in the monoclinic space group P2₁/c. The structure consists of slipped π‐stacks and the interfacial distance between the mean planes of the TTN cores is 3.456 (5) Å, which is slightly larger than that of the comparable derivative of tetrathienoanthracene (TTA) with 2‐hexylthiophene groups. The packing in the two structures is greatly influenced by both the aromatic core of the structure and the alkyl side chains.     

4′‐Iodo‐2,2′:6′,2′′‐terpyridine

In the nearly planar title compound, C₁₅H₁₀IN₃, the three pyridine rings exhibit transoid conformations about the interannular C—C bonds. Very weak C—H...N and C—H...I interactions link the molecules into ribbons. Significant π–π stacking between molecules from different ribbons completes a three‐dimensional framework of intermolecular interactions. Four different packing motifs are observed among the known structures of simple 4′‐substituted terpyridines.