Synthese von benzanellierten Carbacephamen, 1. Mitt.

Summary The direct intramolecular acylation and alkylation of the phenylsulfonylmethyl-group in the -lactames5a and7 are not successful. The postulated intermediate8 of the acylating reaction could be quenched with trimethylchlorosilane as the stable silylketale10. Desulfonation and desilylation of10 leads to the title compound12. The reaction of7 with base does not result in a carbacephame. Instead, the benzo[b]-azepinones15c,d have been obtained.

     

Acetylenchemie, 33. Mitt.: Synthese von 2-substituierten Dihydrofuro[2,3-b]chinolinen

Summary The reaction of 3-iodo-4-methoxy-2(1H)-quinolinone (1) and 3-iodo-4,6,8-trimethoxy-2(1H)-quinolinone (2) with 2-methyl-3-butyn-2-ol under modified Heck-conditions gave the 2-substituted derivatives 2-(1-hydroxy-1-methylethyl)-4-methoxyfuro[2,3-b]-quinoline (3) and 2-(1-hydroxy-1-methylethyl-4,6,8-trimethoxyfuro[2,3-b]-quinoline (4). By a subsequent hydrogenation-reaction with a homogeneous catalyst (PtO₂/Rh₂O₃), the furoquinoline-derivatives yielded the dihydrofuro-[2,3-b]quinolines, identified as 2-(1-hydroxy-1-methylethyl-4-methoxy-2,3-dihydrofuro[2,3-b]quinoline (5) (racemic platydesmine) and 2-(1-hydroxy-1-methylethyl)-4,6,8-trimethoxy-2,3-dihydrofuro-[2,3-b]quinoline (6) (racemic precursor of O⁴-methylptelefolonium salt).

     

Synthese von chinolin-kondensierten 2-Chinolonen und Cumarinen via Azidoverbindungen

Coumarins and 2-quinolones (1), having a 4-azido-3-benzyl-moiety, can easily by cyclized by thermo- or photolysis to 3,4-fused quino-coumarins and quino-2-quinolones (2,3).

     

Synthese von 3,3a-Dihydro-2H,5H-azeto[2,1-b]benzo[d]1,3-oxazin-2,5-dionen, 2. Mitt.

Starting from the thioformimidates4 a, b, c and substituted acetylchlorides, the 3R*/4S* 4-methylthio-2-azetidinones5, 13 a, b, c are synthesized.5 is dehalogenated to6. Debenzylation of6 leads to7 and10, which undergo ring closure to9 and12 by the action of chlorine inDME. Hydrazinolysis of13 a, b, c and acylation of the intermediates14 a, b, c afford15 a, b, c. Removal of the protective groups leads to16 d, e, f. The diastereomeric mixtures17 d, e, f, which are obtained by the chlorolysis of16 d, e, f, undergo ring closure to the 3R*/4S* isomers of the title compounds18 d, e, f either spontaneously or by action of silvertetrafluoroborate/silveroxide. Chlorolysis of19 yields the diastereomeric mixture20. Treatment of20 with silvertetrafluoroborate/silveroxide gives21 and22.

Herrn Professor Dr.Hermann Bretschneider zum 80. Geburtstag gewidmet.     

Eine neue Synthese von Tetrachlordiphosphan sowie Untersuchungen zur 1,2-Addition an Cycloalkene

A New Synthesis of Tetrachlorodiphosphane and Investigations Concerning the 1,2-Addition to Cycloalkenes . The phosphorus subhalide P₂Cl₄ has been synthesized by co-condensation of PCl₃ and Cu vapour in 14% yield. The ³¹P-NMR chemical shift of P₂Cl₄ has the value of δ=155. P₂Cl₄ decomposes during several hours at 0°C in a N₂ atmosphere by a disproportionation process to yield PCl₃ and a yellow polymeric compound of the approximately composition (PCl)_x. P₂Cl₄ is flammable in air to give POCl₃ and (PCl)_x. Investigations regarding the addition of P₂Cl₄ to cyclooctyne, cyclohexene, and cyclohexa-1,4-diene has been carried out. Surprisingly, cyclooctyne does not react with P₂Cl₄ but cyclohexene as well as cyclohexa-1,4-diene undergo 1,2-addition to yield the trans-1,2-bis(dichlorophosphino) substituted carbonhydrides. By derivatization with Me₃Si—NMe₂ the corresponding trans-1,2-bis[bis(dimethylamino)phosphino] compounds are synthesized.     

Heterocyclensynthesen mit 5-Phenyl-isoxazoliumsalzen, 3. Mitt.: Synthese von Pyrrolo[1,2-a]chinazolin-5-onen

Refluxing of ethanol-acetic acid solutions of N-aroyl-N-methyl-benzoylacetamides3 causes elimination of acetophenone and generation of N(1)-substituted N(3)-methyl-1H,3H-quinazoline-2,4-diones5. In contrast, at room temperature in acetanhydride3 eliminate water yielding 2-benzoylmethylene-quinazolinones4, which at 60 °C cyclize to pyrrolo[1,2-a] quinazolin-5-ones6. The transformation4 6 may be explained in terms of a normalKnorr reaction. A anomalousKnorr reaction was observed in the case of the more rigid4 d leading to a mixture of diasteromere7 d cis and7 d trans in kinetically controlled reaction. Favoured by intramolecular hydrogen bonding7 d cis converts to the thermodynamically more stable6 d by warming of the ethanolic solution for 3 hours.

     

Zur Synthese von (±)-cis-1,2-Epoxy-3-oxo-alkyl-phosphonsäureestern—Phosphonomycinanaloga

Treatment of dialkyl-3-oxo-1-alkenylphosphonates1 with OsO₄-H₂O₂ affords the (±)-threo-glycols2, which were characterised as their corresponding diacetates3. The derivatives2 were transformed into the mono-(tert-butyl-dimethylsilylether)-compounds4 and5. Subsequent treatment withp-toluene-sulfonyl chloride yields6 and7, which can be converted to (±)-cis-1,2-epoxy-3-oxoalkylphosphonates8 with tetrabutylammonium fluoride (TBAF). Sometimes thetrans-derivatives9 can be found just as the tosyloxyphosphonates11 and12 as by-products. In two cases the 1,2-dicarbonyl compounds10 were obtained.

Herrn Kollegen Prof. Dr.E. Ziegler zum 70. Geburtstag gewidmet.     

Über die Synthese von Dihydro-1,2,3,5-thiatriazol-1,1-dioxiden, 1. Mitt.

2,5-Dihydro-1,2,3,5-thiatriazole-1,1-dioxides2 a–2 c were obtained on treating N¹-acyl-sulfamoylhydrazides with PCl₅, yielding the corresponding N²-sulfamoyl-carbohydrazonoylchlorides which cyclized after addition of KOH orn-butyllithium.Methylation of2 c yields2 b and the 2,3-isomer10 in a 1 : 1 ratio.Reaction of the nitrilimine11 with the N-sulfonylamine12 affords the tetrazine13 and the isomeric dihydrothiatriazole-1,1-dioxides14 and15 via 1,3-dipolar cycloaddition reaction, while the dihydro-1,2,3,5-thiatriazole-1,1-dioxid16 reacts with ethyl chloroformate to yield the isomers14 and17.

Herrn Prof. Dr. Dr. h.c.K. Kratzl mit den besten Wünschen zum 70. Geburtstag gewidmet.     

Visible light-mediated photocatalytic bromination of 2-arylimidazo[1,2-a]pyridines using CBr4 as bromine source

Abstract

The photocatalytic bromination of 2-arylimidazo[1,2-a]pyridines is described in this paper. This reaction uses the readily accessible and shelf-stable CBr₄ as a bromine source. This photocatalytic system is shown to serve as a convenient and practical synthetic protocol for the preparation of 2-aryl-3-bromoimidazo[1,2-a]pyridines.     

Synthesis and Crystal Structure of 1-（4-Fluorophenyl）-2-hexylthiobenzo[4,5]-furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5（1H）-one

The crystal structure of the title compound 1-(4-fluorophenyl) -2-hexylthio-benzo [4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5(1H) -one(C23H21FN4O2S,Mr = 436.5) has been prepared and determined by single-crystal X-ray diffraction. The crystal is of monoclinic,space group P21/n with a = 13.9854(3) ,b = 17.2678(4) ,c = 18.1828(5) ,β = 99.364(2) °,V = 4332.58(18) 3,Z = 4,Dc = 1.338,F(000) =1824,μ = 0.185 mm-1,MoKa radiation(λ = 0.71073) ,R = 0.0538 and wR = 0.1162 for 4728 observed reflections with I > 2σ(I) . X-ray diffraction analysis reveals the fused rings of benzo[4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a] pyrimidin-5(1H) -one system are nearly coplanar. The crystal packing is mainly stabilized by weak intermolecular C-H···O hydrogen bond and π-π interactions.     

4H-吡啶并[3,2-e][1,3]噻嗪-4-酮嘧啶衍生物的合成

2-氯烟酸异硫氰酸酯在碱性介质中与取代2-氨基嘧啶反应直接得到4H-吡啶并[3,2-e][1,3]噻嗪-4-酮嘧啶. 所合成的6个未见文献报道的目标化合物经IR, ¹H NMR和元素分析证实了其结构, 并对反应可能机理进行了探讨.     

Mass Spectrometry of 2a, 4-Disubstituted 5-Benzoyl-2a, 3,4,5-tetrahydro-2-phenoxy-azeto [ 1,2-a ] [1,5 ] benzodiazepin - 1 （2H）-ones Under Electron Impact Ionization Conditions

The mass spectrometric fragmentation of 2a, 4-disubstituted 5-benzoyl-2a, 3,4, 5-tetrahydro-2-phenoxy-azeto[1,2-α] [ 1,5 ] benzodiazepin-I (2H)-ones has been investigated by means of mass-analyzed ion kinetic energy spectrometry under electron impact ionization conditions. All compounds tend to lose different moieties, such as phenoxy, phenoxy and H, and phenoxyketene. Both [ M^ - PhO ] and [ M^ - PhOH ] ions could further lose CO, and the [ M^ - PhOCH = C = O] ions could lose propene or styrene, PhCON, PhCOHN, and other fragments.     

SYNTHESIS AND ABSORPTION PROPERTIES OF SOME NEW 4-THIO-1,8-NAPHTHYLIMIDES AND 4-(THIO)-7H-BENZIMIDAZO [2,1-A] BENZ [D,E] ISOQUINOLIN-7-ONE DERIVATIVES

A series of new 1,8-naphthylimide and 4-(thio)-7H-benzimidazo[2,1-a]benz[d,e]isoquinolin-7-one derivatives has been synthesized, and the UV/Vis absorptioin characteristics discussed. Substituents' effect on the UV/Vis absorption characteristics have been investigated.     

Synthesis and Characterization of [1,2,4,6]Thiatriazino[2,3-a][1,3]benzimidazol-1(2H)-one and [1,3,5]Thiadiazino[3,4-a][1,3]benzimidazol-2-imine

Abstract

The reaction of thionyl chloride with amidines 2, derived from N-benzimidazol-2-yl imidates 1, leads to [1,2,4,6]thiatriazino[2,3-a][1,3]benzimidazol-1(2H)-one 3 in good yields. [1,3,5]Thiadiazino[3,4-a][1,3]benzimidazol-2-imine 4 was prepared by condensation of NaSCN with benzimidazol-2-yl imidate 1. The isolated compounds 3 and 4 were identified by spectroscopic methods including IR, ¹H NMR, and ¹³C NMR as well as elemental analyses and MS of 3d and 4b.

GRAPHICAL ABSTRACT      

Synthese,Eigenschaften und Struktur von oktamerem Titanimidchlorid [Ti(NSiMe3)Cl2]8

Synthesis, Properties, and Structure of Octameric Titanium Imide Chloride [Ti(NSiMe₃)Cl₂]₈ The reaction of TiCl₄ with N(SiMe₃)₃ in sealed glas-tubes yields the titanium imide chloride [Ti(NSiMe₃)Cl₂]₈ ( 1 ). It crystallizes in the space group C2/c with a = 2 704.5(4), b = 1 303.9(1), c = 2 205.4(2) pm, β = 112.78(1)°, Z = 4. In 1 six Ti atoms are linked together by chloro and trimethylsilylimido bridges to form a ring structure. Two TiCl₂-groups are bound in addition to the ring by two imido bridges. Upon annealing at 250°C 1 transformes to the isomeric polymer [Ti(NSiMe₃)Cl₂]_n. Above 250°C 1 decomposes under separation of Me₃SiCl affording TiNCl.     

A 2D coordination polymer with 4*82 topology constructed from a new T -shaped ligand: synthesis,crystal structure and photoluminescence

A cadmium(II) coordination polymer [CdL(H₂O)] (1) (H₂L?=?3,3-bis(carboxymethyl)imidazo[1,2-a]pyridin-2-one) was synthesized under hydrothermal conditions and characterized by X-ray structure analysis. Compound 1 crystallizes in the monoclinic space group P2₁/n with a?=?11.945(2)?Å, b?=?8.0865(16)?Å, c?=?13.114(3)?Å, β?=?91.36(3)°, Z?=?4, and represents a 2D network with the 4*8² topology constructed from combination of metal centers with a T-shaped geometry and ligands with T-shaped structure simultaneously. Compound 1 also exhibits strong photoluminescence at room temperature.     

Heteroannulated Quinazoline and Quinazolinone Derivatives from (Z)-2-[1-Benzamido-2-(3,4,5-trimethoxyphenyl)]vinyl-3,1-benzoxazin-4(3H)-one

The title compound 1 was prepared and allowed to react with a series of nitrogen nucleophiles to afford the quinazoline and quinazolinone derivatives 2–12 and tetrazole derivative 13. The IR, ¹H NMR, ¹³C NMR, and mass spectra of all the synthesized compounds were discussed.     

Hypervalent Iodine in Synthesis. 94. A Facile Synthesis of 2-Substituted-imidazo[1,2-a]pyridines by Cyclocondensation of Alkynyl(phenyl) iodonium Salts and 2-Aminopyridine

Abstract

A facile method for the synthesis of 2-substituted-imidazo[1,2-a]pyridines is achieved by cyclocondensation of alkynyl(phenyl)iodonium salts with 2-aminopyridine.     

4,5-二[2-(邻甲酰苯氧基)乙硫基]-1,3-二硫环戊烯-2-酮的合成及晶体结构

以水杨醛与1,2-二溴乙烷为反应物, 乙腈为溶剂, 在无水K₂CO₃存在下合成了2-溴乙氧基水杨醛(1), 1和二-(1,3-二硫杂环戊烯-2-硫酮-4,5-二硫)合锌酸四乙基铵盐在乙腈中回流, 得到新型的四硫富瓦烯(TTF)前体(2). 在Hg(OAc)₂存在下, 2可转化为4,5-二[2-(邻甲酰苯氧基)乙硫基]-1,3-二硫环戊烯-2-酮(3), 其结构经¹H NMR, FT-IR, 元素分析和单晶X射线衍射分析得到确证.