Synthesis and structure of 6- and 7-(2-arylvinyl)pteridines

7-Hydroxy-6-styrylpteridine 9 and 7-(2-arylvinyl)-6-hydroxypteridines 10–12 were synthesized via the condensation of 5,6-diaminouracil 1 with benzylidenepyruvic acids 2–4 . The synthesis of the 2-methylthio analogue 15 is also described.     

Heterotricyclodecane IX. 2, 7-Dioxa-isotwistan, 2, 7-Dioxatwistan und 2, 8-Dioxa-homotwistbrendan sowie Derivate

The synthesis of 2, 7-dioxa-isotwistane ( 10 ), 2, 7-dioxa-twistane ( 17 ), and 2, 8-dioxa-homotwistbrendane ( 36 ) and several of their derivatives is described starting from endo-2-hydroxy-9-oxabicyclo[3.3.1]non-6-ene ( 1 ). The 10^O(7)-isotwistane iodide 7 and the corresponding tosylate 15 as well as the 10^O(2)-iodide 9 were treated under reaction conditions suitable for molecular rearrangements involving oxonium ions g and i , respectively, by neighbouring group participation leading to 2, 7-dioxa-twistanes and 2, 8-dioxa-homotwistbrendanes, respectively.     

Heterotricyclodecane XXII 2-Aza-7-thia-isotwistane

2-Aza-7-thia-isotwistanes . 2-Aza-7-thia-isotwistanes were synthesized either starting from suitable 9-thiabicyclo[3.3.1]nonenes by olefin-amination ( 1 → 4 , 2 → 5 , 3 → 6 , 8 → 10 and 9 → 11 ) as well as by intramolecular substitution ( 25 → 26 ) or by molecular rearrangement starting from twistanes ( 21 → 19 and 22 → 10 ). From the isotwistanes thus obtained several other compounds ( 7 , 12 – 18 , 20 , 23 and 24 ) were prepared, too.     

Heterotricyclodecane XVI. 2-Oxa-7-aza-isotwistane und 2-Oxa-7-aza-twistane

The synthesis of several derivatives of 2-oxa-7-aza-isotwistane ( 20–29 and 35 ) and 2-oxa-7-twistane ( 30–34 ) is described starting from cis,cis-cycloocta-1, 5-diene ( 1 ). The bicyclic acetoxy-olefin 10 was used as a key intermediate. The 10^N(7)-isotwistane 22 was treated under reaction conditions suitable for molecular rearrangements involving an oxonium ion g , by neighbouring group participation, leading to 2-oxa-7-aza-twistanes.     

Synthesis and biological screening of 7-hydroxy-4-methyl-2H-chromen-2-one, 7-hydroxy-4,5-dimethyl-2H-chromen-2-one and their some derivatives

7-Hydroxy-4-methyl-2H-chromen-2-one (2), 7-hydroxy-4,5-dimethyl-2H-chromen-2-one (15) and their some derivatives were synthesized for exploring selected biological screening. The compounds 9 and 13 had shown high degree of cytotoxic activity. Three compound 9, 10 and 13 showed high degree of bactericidal activity amongst the present series.     

Synthesis of 2-oxo-3-benzothiazolineacetyl chloride (7), 5-chloro-2-oxo-3-benzothiazolineacetyl chloride (8) and derivatives

The reaction of 2-oxo-3-benzothiazolineacetic acid ( 5 ) and the 5-chloro analogue 6 with thionyl chloride afforded the titled compounds 7 and 8 . The reaction of 7 or 8 with substituted hydrazines, amines or substituted anilines, alcohols and mercaptans furnished the hydrazides 9–14 , acetamides and acetanilides 16–21 , esters 26–30 and thiolesters 31–37 , respectively. Alternate routes for the synthesis of hydrazide 15 , acetamides and acetanilides 22–25 and thiolesters 35–36 are described. The reaction of 2-oxo-3(2H)-benzothi-azolineacetonitrile with thioacetic acid under acidic conditions afforded 2-oxo-3-benzothiazolineethanethio-amide (38).     

2-Alkynylcyclopent-2-enols from 2-Alkynylcyclohex-2-enones via 1-Alkynyl-7-oxabicyclo[4.1.0]heptan-2-ones

2-Alkynylcyclohex-2-enones 1a–c and 2a–c react with H₂O₂/NaOH in MeOH to afford 1-alkynyl-7-oxabicyclo[4.1.0]heptan-2-ones 3a–c and 4a–c , respectively. The 3-unsubstituted bicyclic epoxy ketones 3a, 3b , and 4a, 4b react further with H₂O₂/NaOH, undergoing ring contraction and (formal) decarbonylation to give 2-alkynylcy-clopent-2-enols 5a, 5b , and 6a, 6b , respectively. Epoxy ketones 3 are also obtained under neutral conditions on irradiation (λ = 350 nm) of cyclohexenones 1 in air-saturated benzene solution. Similarly, under neutral conditions oxo-cycloalkenecarbonitriles 8 react (thermally) with H₂O₂ in MeCN to give the oxabicyclic carbonitriles 9 .     

(Mg1–xCrx)2P2O7, CaCrP2O7, SrCrP2O7 und BaCrP2O7 – Neue Diphosphate des zweiwertigen Chroms

Contributions on Crystal Chemistry and Thermal Behaviour of Anhydrous Phosphates. XXXI. (Mg_1–xCr_x)₂P₂O₇, CaCrP₂O₇, SrCrP₂O₇ and BaCrP₂O₇ – New Diphosphates of Divalent Chromium In the quasi‐binary systems A₂P₂O₇/Cr₂P₂O₇ (A = Mg, Ca, Sr, Ba) the solid solution (Mg_1–xCr_x)₂P₂O₇ as well as the new compounds CaCrP₂O₇, SrCrP₂O₇, and BaCrP₂O₇ have been synthesized and characterized for the first time. In the whole experimental range (0.01 < x < 0.94; T = 950 °C) the solid solution (Mg_1–xCr_x)₂P₂O₇ is isotypic to the pure phases β‐Mg₂P₂O₇ and β‐Cr₂P₂O₇; but no phase transition (β → α) to a low‐temperature modification, as in Mg₂P₂O₇ and Cr₂P₂O₇, was found. CaCrP₂O₇ ( A ), SrCrP₂O₇ ( B ), and BaCrP₂O₇ ( C ), phases without detectable homogenity range in the other quasi‐binary systems are not structurally related to each other, but are isotypic to the corresponding compounds containing cobalt. [( A ): P‐1, Z = 2, a = 6.312(2) Å, b = 6.499(2) Å, c = 6.916(2) Å, α = 83.12(3)°, β = 88.37(3)°, γ = 67.72(3)°, 3235 independent reflections, R1 = 0.041, wR2 = 0.112; ( C ): P‐1, Z = 2, a = 5.382(8) Å, b = 7.271(8) Å, c = 7.589(4) Å, α = 103.33(7)°, β = 89.91(9)°, γ = 93.6(1)°, 1571 independent reflections, R1 = 0.085, wR2 = 0.31]. We have reported earlier details on SrCrP₂O₇. The coordination of Cr²⁺ by oxygen is distorted octahedral in ( A) , while in the structures of ( B) and ( C) square‐pyramidal environment is found. The results of UV/VIS‐spectroscopic and magnetic measurements as well as IR‐spectra of the diphosphates are reported.     

Pr4S3[Si2O7] und Pr3Cl3[Si2O7]: Durch weiche Fremdanionen modifizierte Derivate von Praseodymdisilicat

Pr₄S₃[Si₂O₇] and Pr₃Cl₃[Si₂O₇]: Derivatives of Praseodymium Disilicate Modified by Soft Foreign Anions For synthesizing both the disilicate derivatives Pr₄S₃[Si₂O₇] and Pr₃Cl₃[Si₂O₇], Pr, Pr₆O₁₁ and SiO₂ are brought to reaction with S and PrCl₃, respectively, in suitable molar ratios (850 °C, 7 d) in evacuated silica tubes. By using NaCl as a flux, Pr₄S₃[Si₂O₇] crystallizes as pale green, transparent single crystals (tetragonal, I4₁/amd, a = 1201.6(1), c = 1412.0(2) pm, Z = 8) with the appearance of slightly compressed octahedra. On the other hand, Pr₃Cl₃[Si₂O₇] emerges as pale green, transparent platelets and crystallizes monoclinically (space group: P2₁, a = 530.96(6), b = 1200.2(1), c = 783.11(8) pm, β = 109.07(1)°, Z = 2). In both crystal structures ecliptically conformed [Si₂O₇]^6– units of two corner‐linked [SiO₄] tetrahedra with Si–O–Si bridging angles of 131° in the sulfide and 148° in the chloride disilicate are present. In Pr₄S₃[Si₂O₇] both crystallographically independent Pr³⁺ cations show coordination numbers of 8 + 1 (5 S^2– and 3 + 1 O^2–) and 9 (3 S^2– and 6 O^2–). For Pr1, Pr2 and Pr3 in Pr₃Cl₃[Si₂O₇] coordination numbers of 10 (5 Cl^– and 5 O^2–) and 9 (2 ×; 4 Cl^– and 5 O^2– or 3 Cl^– and 6 O^2–, respectively) occur.     

Heterotricyclodecane X. 2-Oxa-7-thia-isotwistan und 2-Oxa-7-thia-twistan sowie Derivate

The synthesis of 2-oxa-7-thia-isotwistane ( 11 ) and 2-oxa-7-thia-twistane ( 22 ) as well as of several of their derivatives is described starting from endo-2-hydroxy-9-thiabi cyclo[3.3.1]non-6-ene ( 4 ). The 10^O(2)-isotwistane bromide 13 , iodide 14 and tosylate 30 as well as the 10^S(7)-isotwistane iodide 15 , tosylate 20 , and the 10^S(7)-twistane tosylate 21 were treated under reaction conditions suitable for molecular rearrangements involving the epi-sulfonium ion i and the oxonium ion g . respectively, by neighbouring group participation.     

7-Halogenated 7-Deaza-2′-deoxyinosines

The synthesis of the 7-deaza-2′-deoxyinosine derivatives 3a – c with chloro, bromo, and iodo substituents at position 7 is described. Glycosylation of the 7-halogenated 6-chloro-7-deazapurines 4a – c or of the 7-halogenated 6-chloro-7-deaza-2-(methylthio)purines 9a – c with 2-deoxy-3,5-di-O-(4-toluoyl)-α-D -erythro-pentofuranosyl chloride ( 5 ) furnished the intermediates 7a – c and 11a – c , respectively, which gave, upon deprotection, the desired nucleosides 3a – c .     

Über den H‐ und A‐Typ von La2[Si2O7]

On the H‐ and A‐Type Structure of La₂[Si₂O₇] By thermal decomposition of La₃F₃[Si₃O₉] at 700 °C in a CsCl flux single crystals of a new form of La₂[Si₂O₇] have been found which is called H type (triclinic, P1; a = 681.13(4), b = 686.64(4), c = 1250.23(8) pm, α = 82.529(7), β = 88.027(6), γ = 88.959(6)°; V_m = 87.223(9) cm³/mol, D_x = 5.113(8) g/cm³, Z = 4) continuing Felsche's nomenclature. It crystallizes isotypically to the triclinic K₂[Cr₂O₇] in a structure closely related to that of A–La₂[Si₂O₇] (tetragonal, P4₁; a = 683.83(7), c = 2473.6(4) pm; V_m = 87.072(9) cm³/mol, D_x = 5.122(8) g/cm³, Z = 8). For comparison, the latter has been refined from single crystal data, too. Both the structures can be described as sequence of layers of each of two crystallographically different [Si₂O₇]^6– anions always built up of two corner‐linked [SiO4] tetrahedra in eclipsed conformation with non‐linear Si–O–Si bridges (∢(Si–O–Si) = 128–132°) piled up in [001] direction and aligned almost parallel to the c axis. They differ only in layer sequence: Whereas the double tetrahedra of the disilicate units are tilted alternating to the left and in view direction ([010]; stacking sequence: AB) in H–La₂[Si₂O₇], after layer B there follow due to the 4₁ screw axis layers with anions tilted to the right and tilted against view direction ([010]; stacking sequence: ABA′B′) in A–La₂[Si₂O₇]. The extremely irregular coordination polyhedra around each of the four crystallographically independent La³⁺ cations in both forms (H and A type) consist of eight to ten oxygen atoms in spacing intervals of 239 to 330 pm. The possibility of more or less ordered intermediate forms will be discussed.     

Synthesis and stereochemical assignment of 7-arylidene and 7-heteroarylidene morphinan-6-ones

A number of (E)-7-arylidenenaltrexones were synthesized by azeotropic distillation of water from a benzene solution of naltrexone and an aromatic aldehyde (benzaldehyde, 4-chloro- and 4-fluorobenzaldehyde, 3-and 4-pyridinecarboxaldehyde and 1-methyl-2-imidazolecarboxaldehyde) using piperidine as a catalyst. In addition, (E)-7-benzylidenenaloxone was prepared by the previously published Claisen-Schmidt condensation using sodium hydroxide in methanol. The stereochemistry of these arylidene derivatives 3–9 was determined to be (E) by means of nuclear Overhauser enhancement experiments. The ¹³C nmr spectra of (E)- 3–9 are recorded in deuteriochloroform and those of the hydrochlorides in deuteriodimethyl sulfoxide.     

Zwei neue Sulfidchloride der Lanthanide: Synthese und Kristallstruktur von Pr7S6Cl9 und Nd7S6Cl9

Two Novel Sulfide Chlorides of the Lanthanides: Synthesis and Crystal Structure of Pr₇S₆Cl₉ and Nd₇S₆Cl₉ The reactions of the elemental lanthanides (M = Pr and Nd, resp.) with sulfur and the respective trichlorides (MCl₃) in evacuated silica tubes (850 °C, 7 d) yield single-phase sulfide chlorides of the composition M₇S₆Cl₉ when appropriate molar ratios (4 : 6 : 3) of the reactants (M : S : MCl₃) are used. A slight excess of trichloride as a flux promotes the formation of lath-shaped transparent single crystals (Pr₇S₆Cl₉: pale green, Nd₇S₆Cl₉: pale violet) which prove to be water soluble and sensitive to hydrolysis. The crystal structure was determined from X-ray single-crystal data taking Nd₇S₆Cl₉ (monoclinic, P2/c (no. 13); a = 2425.0(9), b = 664.2(2), c = 691.8(2) pm, β = 97.43(3)°, Z = 2; R = 0.060, R_w = 0.048) as an example. According to Guinier powder data, Pr₇S₆Cl₉ crystallizes isotypically with a = 2441.6(9), b = 669.1(2), c = 696.3(2) pm, and β = 97.74(3)°. Thus four crystallographically independent cations (M³⁺) are present, each except for M2 coordinated by four S^2– but differing in the number of their next Cl^– neighbors. The figures of coordination are completed by four Cl^– about M1 (square antiprism, CN = 8) and by three Cl^– each about M3 and M4 (monocapped trigonal prisms, CN = 7, 2 Ç ). In contrast, M2 is coordinated by only two S^2– but five (plus one) Cl^– as bicapped trigonal prism (CN = 7 + 1). Eight crystallographically different anions, although indistinguishable by X-ray diffraction, exhibit coordination numbers of four (3 Ç S^2– and 1 Ç Cl^–) and three (4 Ç Cl^–) with respect to the cations. So PbO-analogous layers of the composition ²_∞{[(S6/7Cl_1/7)M_4/4]₇}⁸⁺ parallel (010) are formed, consisting of 6/7 of S^2– and only 1/7 of Cl^– as centering anions for the edge-shared (M³⁺)₄ tetrahedra for reasons of charge neutrality. These cationic layers are held together by alternatingly sheathed layers of Cl^– with only threefold coordinated anions.     

Sm4S3[Si2O7] und NaSm9S2[SiO4]6: Zwei Sulfidsilicate mit dreiwertigem Samarium

Sm₄S₃[Si₂O₇] and NaSm₉S₂[SiO₄]₆: Two Sulfide Silicates with Trivalent Samarium The sulfide silicates Sm₄S₃[Si₂O₇] and NaSm₉S₂[SiO₄]₆ are obtained as light yellow transparent crystals by the reaction of Sm, Sm₂O₃, S, and SiO₂ with fluxing SmCl₃ or NaCl, respectively, in suitable molar ratios in fused evacuated silica tubes (850 °C, 7 d). Tetragonal crystals of Sm₄S₃[Si₂O₇] (I4₁/amd; Z = 8; a = 1186.4(1); c = 1387.0(2) pm) with ecliptically conformed [Si₂O₇]^6–‐groups of corner sharing [SiO₄]‐tetrahedra are formed. These double tetrahedra as well the sulfide anions (S^2–) coordinate two crystallographically independent metal cations. They provide coordination numbers of 8 + 1 (5 S^2– and 3 + 1 O^2–) for Sm1 and 9 (3 S^2– and 6 O^2–) for Sm2. NaSm₉S₂[SiO₄]₆ crystallizes hexagonally (P6₃/m; Z = 1; a = 975.32(9); c = 676.46(7) pm) in a modified bromapatite‐type structure. The coordination spheres about the two crystallographically different Sm³⁺ cations are built up by oxygen atoms of the orthosilicate units ([SiO₄]^4–) and sulfide anions (S^2–). As a result, Sm1 and Sm2 have coordination numbers of 9 and 8, respectively. Na⁺ and (Sm1)³⁺ occupy the position 4 f in a molar ratio of 1 : 3 whereas the lower coordinated (Sm2)³⁺ occupies the 6 h position.     

Sc4Pt7Si2 – An Intergrowth Structure of ScPtSi and ScPt Related Slabs

The metal‐rich silicide Sc₄Pt₇Si₂ was synthesized by arc‐melting. Sc₄Pt₇Si₂ crystallizes with its own structure type, space group Pbam. The structure was refined from single‐crystal X‐ray diffractometer data: a = 647.6(1), b = 1617.1(3), c = 398.96(9) pm, wR2 = 0.0495, 807 F² values and 42 variables. Sc₄Pt₇Si₂ is an intergrowth structure of slightly distorted ScPtSi (TiNiSi type) and ScPt (CsCl type) related slabs. The silicon atoms have the typical coordination number 9 (4 Sc + 5 Pt) in the form of a tricapped trigonal prism. Together, the platinum and silicon atoms build up a complex three‐dimensional [Pt₇Si₂] network with short Pt–Si (238–246 pm) and Pt–Pt (282–303 pm) distances. The scandium atoms fill distorted square prismatic or pentagonal prismatic voids within this network, also with short Sc–Pt distances (276–308 pm). The structural difference of these two scandium species is reflected by substantial discrepancies in ⁴⁵Sc chemical shifts. The quadrupolar interaction parameters that were estimated from the nutation behavior of the two signals were used for an assignment to the two sites.     

The Synthesis of Some 7, 8-Dimethoxy-5-phenyl-2H-3-benzazepin-2-one Derivatives

The benzazepin-2-ones 7 and 9 were prepared from homoveratroyl chloride (4) and phenacylamine. Compounds 7 and 9 were used for the preparation of the benzazepin-2-amines 3, 11, 13 and 14. A synthesis of the benzazepine-1,2-dione 17 and the benzazepine-2,4-dione 20 is also described.     

Photochemical reactions of 7-aminocoumarins. 2. [2 + 2]-cycloadducts with styrene

The photocycloaddition of styrene to 4-methyl-7-aminocoumarin, 4-methyl-7-diethylaminocoumarin, 7-(N-morpholino) coumarin, 3-ethoxycarbonylmethyl-4-methyl-7-diethylaminocoumarin, and coumarin-102 (2,3,6,7-tetrahydro-9-methyl-1H, 5H,11H-[l]-benzopyrano[6,7,8-ij] quinolizin-11-one) was investigated. Adducts of regio- and stereospecific [2 + 2]-cycloaddition to the 3–4 bond were isolated. It was established by means of x-ray diffraction analysis that the phenyl group in the cycloadducts occupies the 1-endo position. The participation of the singlet excited states of the 7-aminocoumarin molecules in [2 + 2]-cycloaddition was demonstrated.See [1] for Communication 1.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1176–1184, September, 1988.     

Synthesis of 2-(2,3,4-trimethoxyphenyl)-1-(substituted-phenyl)acrylonitriles: in vitro anticancer activity against MCF-7, PC-3 and A2780 cancer cell lines

A series of 2-(2,3,4-trimethoxyphenyl)-1-(substituted-phenyl)acrylonitrile (2–9) were designed and synthesized to develop new cancer drugs. The structures of synthesized compounds 2–9 were described by using melting point, mass (MALDI-TOF-MS), FT-IR, elemental analysis, ¹H, ¹³C, ¹³C-APT and 2D NMR spectroscopy. The in vitro anticancer activities of 2–9 against human breast cancer (MCF-7), human prostate cancer (PC-3) and human ovarian cancer cells (A2780) were investigated by [3-(4,5-dimethylthiazol)-2-yl]-2,5-diphenyl-2H-tetrazolium bromide] (MTT) assay method. Additionally, the LogIC₅₀ values of these compounds on A2780, MCF-7 and PC-3 cell lines were calculated by using inhibition % values by the GraphPad Prism 6 program on a computer. The results indicated that these compounds have high anticancer activity against MCF-7, PC-3 and A2780 cell lines (especially A2780 cell lines, p < 0.05).     

Darstellung carboxylatsubstituierter Rhenium-Gold-Metallatetrahedrane Re2(AuPPh3)2(μ-PCy2)(CO)7(η1-OC(R)O) (R = H,Me, CF3, Ph, 3,4-(OMe)2C6H3)

Synthesis of Carboxylate Substituted Rhenium Gold Metallatetrahedranes Re₂(AuPPh₃)₂(μ-PCy₂)(CO)₇(η¹-OC(R)O) (R = H, Me, CF₃, Ph, 3,4-(OMe)₂C₆H₃) The reaction of the in situ prepared salt Li[Re₂(μ-H)(μ-PCy₂)(CO)₇(ax-C(Ph)O)] ( 2 ) with 1,5 equivalents of monocarboxylic acid RCOOH (R = H ( 4 a ), Me ( 4 b ), CF₃ ( 4 c ), Ph ( 4 d ), 3,4-(OMe)₂C₆H₃ ( 4 e ) in tetrahydrofruan (THF) solution at 60 °C gives within 4 h under release of benzaldehyde (PhCHO) the η¹-carboxylate substituted dirhenium salt Li[Re₂(μ-H)(μ-PCy₂)(CO)₇(η¹-OC(R)O)] (R = H ( 4 a ), Me ( 4 b ), CF₃ ( 4 c ), Ph ( 4 d ), 3,4-(OMe)₂C₆H₃ ( 4 e )) in almost quantitative yield. The lower the pK_a value of the respective carboxylic acid the faster the reaction proceeds. It was only in the case of CF₃COOH possible to prove the formation of the hydroxycarbene complex Re₂(μ-H)(μ-PCy₂)(CO)₇(=C(Ph)OH) ( 5 ) prior to elimination of PhCHO. The new compounds 4 a–4 e were only characterized by ³¹P NMR and ν(CO) IR spectroscopy as they are only stable in solution. They are converted with two equivalents of BF₄AuPPh₃ at 0 °C in a so-called cluster expansion reaction into the heterometallic metallatetrahedrane complexes Re₂(AuPPh₃)₂(μ-PCy₂)(CO)₇(η¹-OC(R)O) (R = H ( 7 a ), Me ( 7 b ), CF₃ ( 7 c ), Ph ( 7 d ), 3,4-(OMe)₂C₆H₃ ( 7 e )) (yield 47–71% ). The expected precursor complexes of 7 a–7 e Li[Re₂(AuPPh₃)(μ-PCy₂)(CO)₇(η¹-OC(R)O] ( 8 ) were not detected by NMR and IR spectroscopy in the course of the reaction. Their existence was retrosynthetically proved by the reaction of 7 b with an excess of the chelating base TBD (1,5,7-Triazabicyclo[4.4.0]dec-5-en) forming [(TBD)_xAuPPh₃][Re₂(AuPPh₃)(μ-PCy₂)(CO)₇(η¹-OC(Me)O] ( 8 b ) in solution. The η¹-bound carboxylate ligand in 7 a–7 e can photochemically be converted into a μ-bound ligand in Re₂(AuPPh₃)₂(μ-PCy₂)(μ-OC(R)O)(CO)₆ (R = H ( 9 a ), Me ( 9 b ), CF₃ ( 9 c ), Ph ( 9 d ), 3.4-(MeO)₂C₆H₃ ( 9 e )) under release of one equivalent CO. All isolated cluster complexes were characterized and identified by the following analytical methods: elementary analysis, NMR (¹H, ³¹P) spectroscopy, ν(CO) IR spectroscopy and in the case of 7 d and 9 b by X-ray structure analysis.