Experimental and density functional studies on two structurally similar antipyrine derivatives: 4-(2-hydroxy-5-nitrobenzylidene-amino)-1,2-dihydro-1,5-dimethyl-2-phenylpyrazol-3-one and 4-(3-bromo-5-chloro-2-hydroxybenzylideneamino)-1,2-dihydro-1,5-dimethyl-2-phenylpyrazol-3-one

The Schiff base compounds, 4-(2-hydroxy-5-nitr- obenzylideneamino)-1,2-dihydro-1,5-dimethyl-2-phenylpy- razol-3-one and 4-(3-bromo-5-chloro-2-hydroxybenz- ylideneamino)-1,2-dihydro-1,5-dimethyl-2-phenylpyrazol-3-one, have been synthesized and characterized by elemental analysis, IR, and X-ray single crystal determination. Density functional calculations of the structures, natural bond orbitals, and frontier molecular orbitals and Mülliken charge analysis on the compounds were performed at B3LYP/6-31+G(d) level of theory. Vibrational frequencies were also predicted, assigned, and compared with the experimental values, which supported each other.     

Iron complexes of (e)- and (z)-1,2-dichlorodisilenes

Novel disilene-iron complexes [(E)- (1E) and (Z)-(eta2-R3SiClSi=SiClSiR3)Fe(CO)4 (1Z), SiR3 = tBu2MeSi] were synthesized by the reaction of the corresponding tetrachlorodisilane with an excess amount of K2Fe(CO)4, and the structures of 1E and 1Z were determined by X-ray crystallography. These complexes constitute not only the first transition-metal complexes with E,Z-isomerism but also the first complexes with halogen-substituted disilene ligands. The initial formation of 1Z during the synthetic reaction and the slow one-way isomerization of 1Z to 1E are rationalized by the intervention of the corresponding silylene complex (R3SiCl2Si)(R3Si)Si=Fe(CO)4.     

4-[（Furan-2-ylmethylene）-amino]-1,5- dimethyl-1,2-dihyl-1,2-dihydo-pyrazol-3-one

1 INTRODUCTION Antipyrine (2,3-dimethyl-1-phenyl-5-pyrazolone) and its derivatives exhibit a wide range of biological activities and applications[1～3]. Antipyrine shows mi- nimal protein binding and is rapidly and complete- ly absorbed from the gastrointestinal tract and exten- sively metabolized by the cytochrome P450 liver en- zymes[4]. Estimates of half-life and systemic clear- ance of antipyrine have been used for the in vivo as- sessment of hepatic drug oxidation in different spe- c…     

Synthesis and crystal structure of 4,4′(1,2-ethanediyldiimino)bis(1,1,1-trichloro-3-penten-2-one)

The preparation, characterization and crystal structure of theSchiff base obtained from 1,1,1-trichloroacetylacetone and ethylenediamine is reported. The structural determination shows that the compound is 4,4(1,1-ethanediyldiimino)bis(1,1,1-trichloro-3-penten-2-one), it suggests that the electron accepting ability of the CCl₃ group induces a larger + charge on the remote carbonyl. In the solid state it occurs in two different conformations and N-H ----O hydrogen bond is present.

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Synthese und Kristallstruktur von 4,4(1,2-Ethandiyldiimino)bis(1,1,1-Trichlor-3-penten-2-on)

Zusammenfassung Es wird über die Darstellung, Charakterisierung und Kristallstruktur derSchiff-Base berichtet, die aus 1,1,1-Trichloracetylaceton und Ethylendiamin erhalten wurde. Die Röntgenstrukturanalyse zeigte, daß es sich um 4,4(1,1-Ethandiyldiimino)bis(1,1,1-trichlor-3-penten-2-on) handelt. Dies impliziert, daß die Elektronacceptorfähgkeit der CCl₃-Gruppe eine größere Partialladung + im entfernteren Carbonyl induziert. Die Verbindung besitzt im Kristall zwei verschiedene Konformationen. Es wurde eine N-H----O-Wasserstoff-brückenbinding festgestellt.

     

Photochromism of cis(z)-1,2-bispyrryl-substituted ethene derivatives

Photochromism of two bispyrryl-substituted ethenes, 2, 3-bis-(1-p-methoxyphenyl-5-phenyl-2-methyl-3-pyrryl)-2-butene (BPE1) and 2,3-bis(1-p-bromophenyl-4-phenyl-2-methyl-3-pyrryl)-2-butene (BPE2), was studied by laser flash photolysis technique. The results indicate that photocyclization of these compounds proceeds mainly via the excited triplet state, and the cis-trans isomerization proceeds mainly via the excited singlet state. After UV laser pulse irradiation, both photocylization and cis-trans isomerization of BPEl occur, but photocydization is the main reaction. On the other hand, laser photolysis of BPE2 leads mainly to photocydization. The effects of the substituents on the photochromic mechanism are also discussed.     

Hydrosilylation and hydrogermylation of 3-OXO-1,2-Benzisothiazoline-2-(2-propynyl)-1,1-dioxide

The addition of triethylsilane and triethylgermane to N-propargylsaccharin in the presence of the Speier catalyst gives the gem adduct with trans configuration. This pathway accounts for 75–80% of the reaction.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2889–2891, December, 1991.     

Interaction between 1,2-dimethyl-3-hydroxypyrid-4-one and europium(III)

The interaction of the clinically used 1,2-dimethyl-3-hydroxypyrid-4-one with trivalent europium Eu(III), was investigated by using potentiometric and spectroscopic methods. The stability constants of the EuL_n ⁽³⁻ⁿ⁾⁺ complexes determined by spectroscopic and potentiometric measurements were found to be log β₁₁ = 6.5±0.3 and log β₁₂ = 12.0±0.5. However, at pH ≥ 5, hydrolysis of the Eu-L complexes starts, resulting in the formation of needle-type, yellow crystals. The low solubility of the Eu-L complexes in the neutral pH range is disadvantageous with respect to the use of deferiprone as chelating agent for decorporation of trivalent f-elements.     

Novel heterocyclization of 3-(2-aminophenylamino)- 5,5-dimethyl-2-cyclohexen-1-one

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1,3-Dipolar cycle-addition of 2-diazoalkanes to pyridazin-3(2H)-one derivatives. The formation of 3H-pyrazolo[3,4-d]pyridazin-4(5H)-one and 3H-pyrazolo[3,4-d]pyridazin-7(6H)-one derivatives

1,3-Dipolar cycloadditions of diazoalkanes to pyridazin-3(2H)-ones 1–7 and pyridazin-3(2H)-thiones 8 and 9 are regioselective producing 3H -pyrazolo[3,4-d]pyridazin-4(5H)-ones 15–19, 27–29 and 34–38 as the major products. In some instances, the isomeric 3H-pyrazolo[3,4-d]pyridazin-7(6H)-ones, such as 20 and 23 were isolated as the minor products. From 3 and 6 the primary 3a,7a-dihydro cycloadducts 25 and 26 , and rearranged 1,2-dihydro intermediate 31 were isolated. From 10 and 1-diazoindane the isomeric exo- and endospiro products 39 and 40 were formed.     

1-(SR)-对甲苯亚磺酰基-3-戊烯-2-酮与环戊二烯的不对称催化环加成反应

前文曾报道了α-苯磺酰基-α,β-不饱和酮作为双烯体和亲双烯体所进行的不对称催化HeteroDiels-Alder反应^[1]和Diels-Alder反应^[2].为深入研究其反应机理,提出反应过渡态模型和鉴定环加成物构型.     

Condensation of 2-(3,4-dihydro-6-methoxy-1-naphthyl)-ethenol acetate with 3,5-dimethyl-3-cyclopentene-1,2-dione

Summary The diene condensation of 2-(3,4-dihydro-6-methoxy-1-naphthyl)ethenol acetate (I) with 3,5-dimethyl-3-cyclopentene-1,2-dione (II) goes structurally specifically with formation of an adduct of the steroid type with functional groups in normal positions and an angular methyl group.We are deeply grateful to Prof. Buchta (Erlangen University) for the provision of a sample of 2-ethyl-7-methoxy-1-methylphenanthrene.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1051–1058, June, 1965     

(E)-1,5-二苯基-2-烯-1-戊酮的合成及生物活性研究

(E)-1,5-二苯基-2-戊烯-1-酮(I)是从瑞香狼毒(Stellera chamaejasme L.)中分离得到的天然产物,能有效防治重要农业害虫蚜虫.以价廉易得的苯乙酮为起始原料,经过4步反应合成化合物I,所得目标产物结构经过1HNMR,IR和元素分析确证.并探讨了反应温度和溶剂对产物顺反比例的影响.生物活性测试结果表明,化合物I对桃蚜(Myzus persicae)具有较强的杀蚜活性,其LC50为178.96μg/mL.     

Synthesis of 7- (or 6-)hydroxy derivatives of 3,3-dimethyl-3,4-dihydroisoquinoline

When treated with cyanoacetic ester in conc. H₂SO₄ 1-(4-hydroxy-3-methoxyphenyl)- and 1-(3-hydroxy-4-methoxyphenyl)-2-methylpropan-1-ol form ethyl 7-hydroxy-6-methoxy-3,3-dimethyl(or 6-hydroxy-7-methoxy- 3,3-dimethyl)-1,2,3,4-tetrahydroisoquinolylidene-1-acetate. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 421-425, March, 2009.