1,3‐Dibenzoylimidazolidine‐2‐thione and 1,3‐dibenzo­yl‐3,4,5,6‐tetra­hydro­pyrimidine‐2(1H)‐thione

The title compounds, 1,3‐dibenzo­ylimidazolidine‐2‐thione, C₁₇H₁₄N₂O₂S, (I), and 1,3‐dibenzo­yl‐3,4,5,6‐tetra­hydro­pyrimidine‐2(1H)‐thione, C₁₈H₁₆N₂O₂S, (II), were obtained from the reactions of imidazolidine‐2‐thione and 1,4,5,6‐tetra­hydro­pyrimidine‐2‐thiol, respectively, with benzoyl chloride. Compounds (I) and (II) contain, respectively, imidazolidinethione [C=S = 1.6509 (14) Å] and ­pyrimidinethione [C=S = 1.6918 (19) Å] moieties bonded to two benzoyl rings. The mol­ecules of (I) exhibit C₂ symmetry, the C=S bond lying along the twofold rotation axis, while the mol­ecules of (II) have mirror symmetry (C_s). The imida­zolidine ring in (I) is essentially planar, while the pyrimidine ring in (II) adopts a boat conformation. Mol­ecules of (I) are linked by weak inter­molecular C—H⋯O inter­actions, while mol­ecules of (II) are held together by van der Waals inter­actions.     

Di‐μ‐hydro­xo‐bis­(diiso­propyl­gallium)–1,4,8,11‐tetra­methyl‐1,4,8,11‐tetra­aza­cyclo­tetra­decane (1/1)

The hydro­lysis product [Ga₂(C₃H₇)₄(OH)₂]·C₁₄H₃₂N₄, derived from the tetrakis­(triiso­propyl­gallium)–1,4,8,11‐tetra­methyl‐1,4,8,11‐tetra­aza­cyclo­tetra­decane (1/1) adduct, consists of a centrosymmetric [ⁱPr₂Ga(μ‐OH)]₂ unit hydrogen bonded through the hydroxyl group to a nitro­gen on an adjacent centrosymmetric 1,4,8,11‐tetra­methyl‐1,4,8,11‐tetra­aza­cyclo­tetra­decane molecule, resulting in the generation of a molecular chain through the crystal.     

Photocyclodimerization of 5‐Methyl‐2H‐pyran‐3(6H)‐one

The structures of the main products resulting from photocyclodimerization of the title compound 2 and of other 3‐methyl‐substituted ‘oxacyclohex‐2‐en‐1‐ones’ (=dihydropyranones) were determined by X‐ray crystallography. In connection, the ¹³C‐NMR chemical shifts of the cyclobutane C‐atoms of these dimers allow a clear differentiation between head‐to‐head and head‐to‐tail regioisomers, all structurally related to those of isophorone ( 1 ).     

1H‐Imidazol‐1‐yl 1,2,3,4‐tetra­hydro­isoquinolin‐2‐yl ketone

In the crystal structure of the title compound, C₁₃H₁₃N₃O, the C—N_imidazole bond length of 1.431 (3) Å is shorter than that observed [1.466 (6) Å] in the corresponding carbamoyl­imidazolium salt 3‐methyl‐1‐(1,2,3,4‐tetra­hydro­isoquinolin‐2‐yl­carbonyl)­imidazolium iodide. A comparision of these compounds is used to highlight the structural differences that occur as a result of the imidazolium effect. Weak C—H⋯O hydrogen bonds link mol­ecules into extended tapes in the a direction.     

3‐[4‐(3,4‐Di­methyl­phenyl)‐1,3‐thia­zol‐2‐yl]‐2‐(2‐hydroxy­phenyl)‐1,2,3,4‐tetra­hydro­quin­az­olin‐4‐one

The facile one‐pot synthesis of the title compound, C₂₅H₂₁N₃O₂S, is described. The six‐membered 1,3‐di­aza ring is puckered with an axial phenyl group in the 2‐position. Intermolecular hydrogen bonding between hydroxyl and ketonic O atoms produces infinite one‐dimensional chains in the a direction.     

1‐Methyl‐5,6‐di­phenyl­pyrazine‐2(1H)‐thione

The title compound, C₁₇H₁₄N₂S, crystallizes in a triclinic unit cell, with two crystallographically independent mol­ecules in the asymmetric unit. The two independent mol­ecules pack in the same sense and form segregated layers along the c axis. The crystal is light‐stable and no dimers are formed under irradiation. The intermolecular distances between the potential reactive centers (the C‐3 and C‐5 ring positions) are 4.093 (4) and 5.643 (4) Å for mol­ecule A, and 4.081 (4) and 5.614 (4) Å for mol­ecule B.     

(RS)‐6‐Ethyl 2‐carboxy‐1,2,3,4‐tetra­hydro­azulene‐6‐carboxylate

The title compound, C₁₄H₁₆O₄, was obtained during the synthesis of 2,6‐disubstituted azulene derivatives. In the partially reduced azulene skeleton, the absence of a H atom at the ester substitutent position of the seven‐membered ring, as well as lengthened double bonds, indicate a conjugative stabilized system with two overlaid tautomers.     

5‐Amino‐6‐phenyl‐1,6‐di­hydro­pyridazin‐3(2H)‐one

In the title compound, C₁₀H₉N₃O, the pyridazinone moiety is essentially planar and forms a dihedral angle of 49.5 (1)° with the phenyl substituent. The molecular packing is stabilized by van der Waals interactions and hydrogen bonds.     

Di‐μ‐phenyl­thio‐bis­[bis(η5‐methyl­cyclo­penta­dienyl)(tetra­hydro­furan)lanthanum(III)] bis­(tetra­hydro­furan) solvate

The title complex, [La₂(C₆H₇)₄(C₆H₅S)₂(C₄H₈O)₂]·2C₄H₈O, is a centrosymmetric dimer bridged through the S atoms of the benzene­thiolate ligands. The bridging La₂S₂ unit is completely planar, while the geometry around the nine‐coordinate La atom is that of a distorted trigonal bipyramid. The La—S—La and S—La—S angles are 117.51 (4) and 62.5 (1)°, respectively, and the average La—S bond length is 2.9759 Å. The crystals contain two tetra­hydro­furan solvate mol­ecules for every complex mol­ecule.     

Tetrakis­(tetra­hydro­furan‐κO)­lithium mer‐tris­(carbazolyl‐κN)‐trans‐di­chloro(tetra­hydro­furan‐κO)­zirconate

In the title compound, [Li(C₄H₈O)₄][ZrCl₂(C₁₂H₈N)₃(C₄H₈O)], the environment of the Zr atom is pseudo‐octahedral, with the three carbazolyl ligands in a mer configuration. The counter‐ion of the zirconium complex is composed of an Li atom surrounded by four tetra­hydro­furan (THF) mol­ecules. The THF mol­ecule attached to the Zr atom is disordered over two sites, as are two of the THF mol­ecules in the lithium moiety. All bond distances and angles are consistent with those in complexes with similar structural entities. The Zr—N bond distances are 2.2185 (18) and 2.167 (3) Å.     

3‐(p‐Chloro­phenyl)‐4‐phenyl‐4,5‐di­hydro­isoxazole‐5‐spiro‐2′‐1′,2′,3′,4′‐tetra­hydro­naphthalen‐1′‐one

In the title compound, C₂₄H₁₈ClNO₂, the phenyl ring and the tetralone moiety are approximately orthogonal to the isoxazoline ring. The isoxazoline ring adopts an envelope conformation, while the cyclo­hexenone ring of the tetralone moiety has an intermediate sofa/half‐chair conformation. In this structure, one C—H?N intermolecular and two C—H?O intramolecular hydrogen bonds occur; the H?A distances are 2.60, and 2.35 and 2.57 Å, respectively. The mol­ecules are held together by an intermolecular C—H?N hydrogen bond, forming a one‐dimensional chain along the [100] direction.     

Mol­ecular packing in (5‐methyl‐2,4‐dioxo‐1,2,3,4‐tetra­hydro­pyrimidin‐1‐yl)acetamide

In the title compound, C₇H₉N₃O₃, the primary packing motif, viz. an infinite tape, is formed via inter­molecular hydrogen bonds of different strengths. In the formation of the tapes, only inversion centres are used; the other symmetry elements of P2₁/c connect the tapes into a three‐dimensional structure through only weak hydrogen bonds.     

Bis(1‐methyl­guanidinium) tetra­chloro­cuprate(II) and 4‐(2‐pyrimidin‐1‐io)­piperazinium tetra­chloro­cuprate(II)

The crystal structures of the title compounds, (C₂N₃H₈)₂[CuCl₄], (I), and (C₈H₁₄N₄)[CuCl₄], (II), have been studied by X‐ray diffraction. The structures consist of discrete [CuCl₄]^2? anions with two monoprotonated (C₂N₃H₈)⁺ cations for (I) and a diprotonated (C₈N₄H₁₄)²⁺ cation for (II). The [CuCl₄]^2? anions of both compounds have flattened tetrahedral geometries. There are several N—H?Cl weak bonds that join the [CuCl₄]^2? anions and the organic cations helping retain the pseudo‐tetrahedral geometries of the anions.     

A Convenient Synthesis and Biological Research of Novel 5,6,7,8‐Tetrahydro‐1,6‐naphthyridin‐2(1H)‐one Derivatives Hydrochloride as Cytotoxic Agents

A series of 5,6,7,8‐tetrahydro‐1,6‐naphthyridin‐2(1H)‐one derivatives hydrochloride were obtained using a convenient and mild method from 4‐piperidone monohydrate hydrochloride. The newly synthesized compounds and their derivatives were characterized by ¹H NMR, ¹³C NMR, and high‐resolution mass spectrometry. Furthermore, cytotoxicity in vitro of the synthesized compounds were screened using MTT or CCK8 assay. The results showed that some of the compounds showed potential antitumor activity. Among of them, compound 10a had effects against tumor cells (MOLM‐13), and the half maximal inhibitory concentration value was 76 μmol/L.     

2‐Iso­propyl‐4‐methyl‐4‐phenyl‐1,2,3,4‐tetra­hydro­iso­quinoline‐1‐thione

The title compound, C₁₉H₂₁NS, is the photoproduct obtained from N‐iso­propyl‐N‐[(E)‐2‐phenyl­propenyl]­thio­benz­amide. Recrystallization showed a spontaneous resolution.     

Synthesis,Characterization, and Physical Properties of a Conjugated Heteroacene: 2‐Methyl‐1,4,6,7,8,9‐hexaphenylbenz(g)isoquinolin‐3(2H)‐one (BIQ)

We report the synthesis and characterization of a novel, stable and blue heteroacene, 2‐methyl‐1,4,6,7,8,9‐hexaphenylbenz(g)isoquinolin‐3(2H)‐one (BIQ 3 ). BIQ 3 , with its relatively small π framework, has an absorption λ_max at 620 nm, which is larger than that of pentacene (λ_max=582 nm), but BIQ 3 is more stable. The solutions of BIQ 3 are observed without any noticeable photobleaching on the order of days. In the solid state, it is very stable at ambient conditions and can be stored indefinitely. Owing to its pyridone end unit, BIQ 3 can display different resonance structures in different solvents (aprotic and protic) or Lewis acids to give different colors. The attractive stability exhibited by BIQ 3 is very desirable in organic semiconductor devices. Herein, we investigated a simple heterojunction photovoltaic device based on BIQ 3 as an electron donor and [6,6]‐phenyl‐C₆₁ butyric methyl ester as an electron acceptor. Our results show that this type of heteroacene could be a good candidate as a charge‐transport material in organic semiconductor devices.     

(1S,2R,2′S)‐ and (1S,2S,2′S)‐1‐phenyl‐2‐phenyl­thio‐2‐(tetra­hydro­pyran‐2′‐yl­thio)­ethanol diastereoisomers at 193 K

In the synthesis of 1‐phenyl‐2‐phenyl­thio‐2‐(tetra­hydro­pyran‐2‐yl­thio)­ethanol, C₁₉H₂₂O₂S₂, four diastereoisomers are formed. Two non‐centrosymmetric enantiomeric forms which crystallize in space groups P2₁2₁2₁ and Pna2₁ are presented. The former has an intramolecular hydrogen bond between the hydroxyl group and the O atom of the tetra­hydro­pyran ring. In the latter isomer, the hydroxyl group forms an intermolecular hydrogen bond to the O atom of the tetra­hydro­pyran­yl group of a neighbouring mol­ecule, joining the mol­ecules into chains in the c‐axis direction; the O?O distances are 2.962 (4) and 2.764 (3) Å, respectively. The tetra­hydro­pyran rings are in chair conformations in both isomers and the S side chain has an equatorial orientation in the former, but an axial orientation in the latter mol­ecule.     

1‐Benzyl‐3,3‐dichloro‐1H‐indol‐2(3H)‐one

The title compound, C₁₅H₁₁Cl₂NO, was synthesized from N‐­benzyl­isatin. The compound crystallizes as stacks of mol­ecules running down the c axis. Mol­ecules within each of these stacks inter­act with each other through π–π and C—H⋯π inter­actions, and inter­act with neighbouring stacks through C—H⋯O inter­actions.     

(18‐Crown‐6)‐μ‐oxo‐hexa­kis(tetra­hydro­borato)diuranium(IV): an unprecedented asymmetric dinuclear complex

In the title compound, (1,4,7,10,13,16‐hexa­oxacyclo­octa­decane‐1κ⁶O)‐μ‐oxo‐1:2κ²O:O‐hexa­kis(tetra­hydro­borato)‐1κ³H;2κ²H;2κ²H;2κ³H;2κ³H;2κ³H‐diuranium(IV), [U₂(BH₄)₆O(C₁₂H₂₄O₆)], one of the U atoms (U1), located at the centre of the crown ether moiety, is bound to the six ether O atoms, and also to a tridentate tetra­hydro­borate group and a μ‐oxo atom in axial positions. The other U atom (U2) is bound to the same oxo group and to five tetra­hydro­borate moieties, three of them tridentate and the other two bidentate. The two metal centres are bridged by the μ‐oxo atom in an asymmetric fashion, thus giving the species (18‐crown‐6)(κ³‐BH₄)U=(μ‐O)—U(κ³‐BH₄)₃(κ²‐BH₄)₂, in which the U1=O and U2—O bond lengths to the μ‐O atom [1.979 (5) and 2.187 (5) Å, respectively] are indicative of the presence of positive and negative partial charges on U1 and U2, respectively.     

Identification of (6R)‐5,6,7,8‐Tetrahydro‐D‐monapterin (=(6R)‐2‐Amino‐5,6,7,8‐tetrahydro‐6‐[(1R,2R)‐1,2,3 ‐trihydroxypropyl]pteridin‐4(3H)‐one) as the Native Pteridine in Tetrahymena pyriformis

The structure of the native pteridine in Tetrahymena pyriformis was determined as (6R)‐5,6,7,8‐tetrahydro‐D ‐monapterin (=(6R)‐2‐amino‐5,6,7,8‐tetrahydro‐6‐[(1R,2R)‐1,2,3‐trihydroxypropyl]pteridin‐4(3H)‐one; 4 ). First, the configuration of the 1,2,3‐trihydroxypropyl side chain was confirmed as D ‐threo by the fluorescence‐detected circular dichroism (FDCD) spectrum of its aromatic pterin derivative 2 obtained by I₂ oxidation (Fig. 1). The configuration at the 6‐position of 4 was determined as (R) by comparison of its hexaacetyl derivative 6 with authentic (6R)‐ and (6S)‐hexaacetyl‐5,6,7,8‐tetrahydro‐D ‐monapterins 6 and 7 , respectively, in the HPLC, LC/MS, and LC‐MS/MS (Figs. 3 – 6). (6R)‐5,6,7,8‐Tetrahydro‐D ‐monapterin ( 4 ) is a newly discovered natural tetrahydropterin.