Pinacol-Pinacolone Rearrangement of 1, 2-Di-(p-methoxyphenyl)-ethane-1, 2-diol and Bis-(4-methoxyphenyl)-acetaldehyde in Acid Media

1, 2-Di-(p-methoxyphenyl)-ethane-1, 2-diol gave in acid media bis-(4-methoxy-phenyl)-acetaldehyde, 4-4′-dimethoxy-deoxybenzoin, and 1, 2-di-(p-methoxyphenyl)-ethylene oxide; their respective yields being influenced by at least 3 factors: (i) the acid, (ii) its concentration, and (iii) the reaction period. Bis-(4-methoxyphenyl)-acetaldehyde rearranged to the deoxybenzoin in boiling sulfuric (50%) or phosphoric (75%) acids (w/w), and to two isomeric 1, 2-diacetoxy-1, 2-di-(p-methoxyphenyl) ethanes when it was heated with acetic anhydride. The mechanisms of these reactions are discussed.     

Synthesis and in vitro Antimicrobial Activity of Nalidixic Acid Hydrazones

A series of nalidixic acid‐based hydrazones have been synthesized and evaluated for their in vitro antimicrobial activity using the broth microdilution method against a panel of reference strains of microorganisms, including Gram‐positive bacteria, Gram‐negative bacteria, and fungi belonging to yeasts Candida spp. and molds Aspergillus spp., Penicillium spp., and Rhizopus spp. Nalidixic acid derivatives were obtained by condensation reaction of nalidixic acid hydrazide with substituted (hetero)aromatic aldehydes. All compounds have been characterized by ¹H NMR and ¹³C NMR spectra. The antimicrobial activity indicated that compound with indole substituent could be a promising lead for future development of active antifungal agents.     

Synthesis and Rearrangement of N-PIII-Phosphorylated Carboxylic Acid Amides

Abstract

Reactions of carboxylic acid lactams with tervalent phosphorus chlorides, leading to N- and/or O- derivatives have been investigated. Synthetic methods for imidoylphosphites and phosphonates, mono- and bisphosphorylated azadienes have been developed. Prototropic migrations in azaallylic triad, phosphorus atom migrations in N-C-O triad and imidoylphosphite-imidoylphosphonate rearrangement were found. It was encountered, that chlorination of amidophosphites containing one to three trihalogen acetamide groups is accompanied by chlorine or N-acylamide group shift and leads to cyclic and spirocyclic phosphoranes with 1,3,2-⁵-oxazaphosphetanic cycle.     

Synthesis of Branched Hydrazones by Reaction of N-(2,3-Epoxypropyl) Derivatives of Hydrazones with Benzenediols

A series of branched hydrazones have been prepared by reaction of N-(2,3-epoxypropyl) derivatives of 9-ethyl-3-carbazolecarbaldehyde and 4-diethylamino-benzcarbaldehyde phenylhydrazones with 1,2-, 1,3-, and 1,4-benzenediols. It was found that the reaction rate depends on the polarity of solvents.     

Synthesis of Bis-(2-mercaptoimidazole)-4,4-butylidene

Ethyl butylidene-bis-3-phthalimidoacetoacetate (II) was prepared by condensation of ethyl-3-phthalimido-acetoacetate and n-butyraldehyde in the presence of piperidine in benzene. Compound II was hydrolysed by hydrochloric acid followed by cyclization with potassium thiocyanate to yield bis(2-mercaptoimidazole)-4,4-butylidene (IV).     

一顺丁烯二酸异丙酯酰氧基二异丙氧基镝的合成和聚合

用三异丙氧基镝与顺丁烯二酸酐反应合成－顺丁烯二酸异丙酯酰氧基二异丙氧基镝,ＤＭ在偶氮二异丁腈引发下通过溶液聚合制得含Ｄｙ聚合物。     

Synthesis and performance of a Mono (dodecafluoroheptyl) acetate surfactant

A novel fluorinated surfactant, sodium 1?H, 1?H, 7H-dodecafluoro-1-heptyloxy acetate (DFHAS), was synthesized via a facile two-step synthetic procedure. The structure of product on each step was characterized by ^1?H NMR, ^19?F NMR, ¹³C NMR, FT-IR, and mass spectrum (MS). Ultraviolet absorption (UV) and ring measurements were performed to obtain detailed information of its surface properties. The results demonstrated that the novel surfactant possessed very low critical micelle concentration (CMC, 7.94?mM) and surface tension (20.01?mN/m). Furthermore, the surfactant had preferable thermal stability compared with other perfluorocarboxylates characterized by thermal gravimetric analysis (TGA). The practical application performance of DFHAS was finally validated through the emulsion polymerization of vinylidene fluoride (VDF) by means of its excellent emulsifying activities. It is expected that this versatile synthetic strategy may help fabricate satisfying green surfactant systems for the application in fields of emulsion polymerization, drug delivery and greases.GRAPHICAL ABSTRACT     

双[(五甲二硅基)环戊二烯基]四羰基二铁的合成结构及性质

五甲二硅基与环戊二烯基羰基过渡金属化合物的金属直接配位的已有不少报道,但五甲二硅基取代环戊二烯基的羰基过渡金属化合     

高单酯含量的甲基丙烯酸-β-羟乙酯磷酸酯的催化合成

采用浸渍法将磷钨酸及其盐[TEAH]₃PW₁₂O₄₀负载到活性炭上制备出HPW/AC和TEAPW/AC 2个系列的催化剂,并用IR、XRD、N₂-吸附脱附和NH₃-TPD等技术手段对它们的结构和酸性进行了表征。进一步,以P₂O₅为磷酸化剂考察了上述催化剂在功能性磷酸酯-甲基丙烯酸-β-羟乙酯磷酸酯合成中的催化性能。结果显示,上述催化剂在该酯化反应中不仅具有很高的活性,而且由于催化剂的微孔结构抑制了双、三酯的生成,明显提高了单酯的选择性。在优化的反应条件和催化剂上,酯化率可达94%,单酯选择性可达95%。且催化剂高度稳定,可以重复使用。该催化剂和催化工艺不仅克服了磷酸酯合成中使用含氯原料的缺点,而且大大提高了产物中单酯的含量。     

二[氧合-二(3-二茂铁基丙烯酸二正丁基锡(Ⅳ))]配合物的合成及谱学表征

由FcCH=CHCO2H和(n Bu)2SnO反应合成了{[(FcCH=CHCO2)Sn(n Bu)2]2O}2(A)新配合物[其中Fc=(η5 C5H5)Fe(η5 C5H4)].经红外光谱和核磁共振(1H、13C、119Sn)谱学研究, 确定其组成和结构.提出 [(RCOOSnR′2)2O]2类化合物中一一指认与内环锡、外环锡键连的两类烷基R′中各个碳峰的原则.     

双(2,2-二硝基丙基)肼甲硼氢络合物的合成及性能研究

本文报道了双(2,2-二硝基丙基)肼甲硼氢络合物的合成及其性能。实验表明,该络合物在较低温度下(0～5℃)有一定安定性,放置几天后,基本不变,在稍高温度下(20～25℃)放置1～2小时即迅速分解,自燃或自爆。此外,还讨论了可能的机理。     

Synthesis and Crystal Structure of Tetra（diisopropylamido—N）ytterbium Mono（tetrahydrofuran—O）lithium

1 INTRODUCTION The lanthanide amide complexes are excellent synthetic precursors for lanthanide derivatives, par- ticularly in the reactions involving protonic rea- gents[1]. A few types of lanthanide amide complexes, from homoleptic three- to four-coordinate, have been known for some time[2～4]. Recently, we begin to examine the utility of amide with less steric bulk, such as diphenylamide and diisopropyamide, as li- gands to synthesize homoleptic lanthanide amide complexes. For diphen…     

Synthesis of N,N-Disubstituted Lactone Hydrazones via (Sulfonylimino)-ethers

The dihydropyran 3 reacts with sulfonyl azides to give the known (sulfonylimino)-ethers ( = lactone sul-fonylimines) 4 and 18 . Reaction of 4 with NH₂NH₂ · H₂O leads to the aminoiriazole-dibulanol 5 , characterized as its tetraacetate 8 , and not, as previously claimed, to 6 or 7 . Similarly, the dihydrofuran-derived (tosylimino)-ether 10 yields 11 The structure of 5 was established by X-ray analysis, and a mechanism for its formation is proposed. Reaction of 4 with NH₂NMe₂ afforded the lactone hydrazone 16 and the hydrazidine 17. Catalysis by imidazole suppressed the formation of 17 similarly, the [(trifluoromethyl)sulfonyl]imine 18 yielded 16, and, by reaction with NH₂N(Me)Ph or 4-amino-4H-1,2,4-triazole, the lactone hydrazone 19 and the adduct 20 , respectively. The 1,4-lactone hydrazone 21 was obtained from 10 or from 22 . The structure of 20 was established by X-ray analysis. Treatment of 16 with BuLi followed by BnBr yielded the α-alkylated lactone hydrazone 23 .     

Synthesis and Unexpected Rearrangement of a Hydroxyphostone (1)

Abstract

During our investigations on the wide range of stereoselective alkylations of 6-membered ring phostones,¹ we uncovered a novel rearrangement of 3-(diphenylhydroxymethyl)-2-ethoxy-2-oxo-1,2-oxaphosphorinane (1). The cis/trans diastereomers of 1 were prepared by the reaction of benzophenone with the appropriate ylide of the parent phostone (3).² When trans- 1 was left unattended at rt in CH₂Cl₂ a new compound, 2, was isolated which showed a significant downfield ³¹P shift and a higher melting point. Upon heating to the melting point 2 decomposed to give 4, which suggests that 2 may be an intermediate in the conversion of 1 to the Wittig-like product 4. The IR, ¹H, ¹³C, ³¹P, and 2-D NMR spectral data along with independent synthesis confirmed the identity of 2. Subsequently, 2 was also produced in 70% yield when cis- 1 was treated with CH₂Cl₂/ether-HC1_aq at 50–60°C for 2 weeks, but this product was contaminated with 30% of the exocyclic alkene 5. No rearrangement was observed when 1 was treated with TsOH/EtOH or HPF₆; only 5 was produced. The stereochemistry and mechanisms of these transformations are presented.     

Acetals of Dehydro-L-Ascorbic Acid 2-Hydrazones. Access to the Chiral Building Block (R)-Glycerol Acetonide

5,6-O-Isopropylidene, cyclohexylidene and benzylidene derivatives of L-threo-2,3-hexodiulosono-1,4-lactone 2-phenylhydrazone were prepared. Reduction of the isopropylidcne derivative was followed by treatment with base, and then periodate oxidation and reduction to give (R)-glycerol acetonide. Hydrogen bonding in the hydrazones has a role in forming geometrical isomers.     

Bis-(trialkylsilyl) phosphonates

Summary Methods of synthesis of the previously unknown bis-(trialkylsilyil) phosphonates were developed on the basis of reaction of phosphorous acid with trialkylchlorosilanes or trialkylalkoxysilanes. Their Raman spectra were studied.     

Denitrogenative Hydrotrifluoromethylation of Benzaldehyde Hydrazones: Synthesis of (2,2,2-Trifluoroethyl)arenes

Reacting hydrazones of arylaldehydes with Togni's CF₃-benziodoxolone reagent, in the presence of potassium hydroxide and cesium fluoride, induces a denitrogenative hydrotrifluoromethylation event to produce (2,2,2-trifluoroethyl)arenes. This novel reaction was tolerant to many electronically-diverse functional groups and substitution patterns, as well as naphthyl- and heteroaryl-derived substrates. Advantages of this process include the easy access to hydrazone precursors on a large scale, speed and operational simplicity, and being transition metal-free.     

Synthesis and Characterization of Acetone Hydrazones

1‐Isopropylidene‐2‐methylhydrazine ( 1 ), 1‐isopropylidene‐2‐hydroxyethylhydrazine ( 2 ) and 1‐isopropylidene‐2‐formylhydrazine ( 3 ) were synthesized by reaction of the corresponding hydrazine with an excess of acetone in the presence of a drying agent (anhydrous sodium sulfate or barium oxide). All compounds 1 – 3 were characterized by elemental analysis, coupled gas chromatography‐mass spectrometry (GC–MS), multinuclear NMR spectroscopy (¹H, ¹³C and ¹⁵N) and vibrational spectroscopy (infrared and Raman). Compounds 1 and 2 are liquid at room conditions and their density was measured by means of a picnometer, however, (at room conditions) compound 3 is a solid and its crystal density and structure were determined by low temperature X‐ray diffraction techniques (monoclinic, P2₁/n, Z = 4, a = 5.666(1) Å, b = 6.254(1) Å, c = 15.277(4) Å, β = 91.30(2)°, V = 541.2(2) ų). The structure of hydrazone 3 is discussed in detail and compared to that of monoformylhydrazine. Finally, the (gas phase) structure of compound 3 was optimized using DFT calculations (B3LYP/6‐31+G(d, p)) and its NBO charges are reported.     

异丙氧基-异羟肟酸-氧钒（V）配合物的合成、晶体结构和量子化学研究

以苯甲酰异羟肟酸为配体,首先合成四价氧钒化合物,以此为基础合成了标题 化合物,并用元素分析,红外光谱,~1H NMR,~(13)C NMR,~(15)V NMR,电子吸 收光谱等,分别对它进行了表征,其结构用单晶X射线衍射法测定,晶体属三斜晶 系,P1-bar空间群,所得晶体学参数为a = 1.1119(3) nm,b = 1.1735(3) nm,c = 0.8660(2) nm,α = 96.84(1)°,β = 106.93)(1)°,γ = 88.97(1)°,V = 1.0731(2) nm~3,D_c = 1.415 g/cm~3,Z = 2,F(000) = 478,μ = 5.06 cm~(-1)。采取ab initio(GTO-6-31d)方法对标题化合物的结构单元的成键情况进 行了分析,讨论了化合物的稳定性、分子轨道能量、原子静电荷分布等情况。