Reaction of 4-Ethoxyl-1,1,1-trifluoromethyl-3-butenone with perfluorophenyl hydrazine and perfluoroalkyl hydrazides

The presence of fluorine in biologically active compounds can impart a profound influence on their biological active. This influence has lead to the development of several potent agricultural and therapeutic agents[1]. During the study on the reactions of 4 - ethoxyl - 1, 1, 1 -trifluoromathyl-3-butenone 1, we found which is a very useful building-block in synthesis of fluoro-containing heterocyclic compounds[2]. Compound 1 can react with perfluorophenyl hydrazine and afford 1- perfluorophenyl-5-trifluoromethyl- 5 -hydroxy-4, 5 -2H- pyrazole 2 in excellent yield. It’s structure is further supported by X-ray diffraction.

Chemical synthesis of Ub-AMC via ligation of peptide hydrazides

The C-terminal conjugate of ubiquitin with 7-amino-4-methylcoumarin （Ub-AMC） is an important probe for fluorescencebased analysis of deubiquitinating enzyme （DUB） activity. It is important to develop more efficient methods for the preparation of Ub-AMC because the currently available technology is still expensive for scaled-up production. In the present work we report an efficient strategy for total chemical synthesis of Ub-AMC through ligation of peptide hydrazides. Three peptide segments are assembled via N-to-C sequential ligation and the resulting product is converted to Ub-AMC via TCEP-mediated desulfurization. The synthetic Ub-AMC is shown to have expected biological functions throug

Synthesis,antimicrobial evaluation and QSAR studies of 3-ethoxy-4-hydroxybenzylidene/4-nitrobenzylidene hydrazides

A series of 3-ethoxy-4-hydroxybenzylidene/4-nitrobenzylidene hydrazides（1-20） was synthesized and tested for in vitro antimicrobial activity.The results of antimicrobial studies indicated that the compounds having dinitro,methoxy,hydroxy and nitro substituents on phenyl ring of the aromatic acids were most active ones.The QSAR investigation indicated the importance of the topological parameter,third order molecular connectivity index（~3x） in describing the antimicrobial activity of synthesized hydrazides.

H_(4)SiW_(12)O_(40)-catalyzed cyclization of epoxides/aldehydes and sulfonyl hydrazides: An efficient synthesis of 3,4-disubstituted 1H-pyrazoles

A simple and efficient method for the synthesis of pyrazoles through a silicotungstic acid (H_(4)SiW_(12)O_(40))-catalyzed cyclization of epoxides/aldehydes and sulfonyl hydrazides has been developed. Various epoxides/aldehydes were smoothly reacted with sulfonyl hydrazides to furnish regioselectivity 3,4-disubstituted 1H-pyrazoles. The application of such an earth-abundant, readily accessible, and nontoxic catalyst provides a green approach for the construction of 3,4-disubstituted 1H-pyrazoles. A plausible reaction mechanism has been proposed on the basis of control experiments, GC-MS and DFT calculations.

Copper-Catalyzed Aerobic Oxidative Cleavage of Unstrained Carbon-Carbon Bonds of 1,1-Disubstituted Alkenes with Sulfonyl Hydrazides

Main observation and conclusion Alkoxy radical-mediated carbon-carbon bond cleavages have emerged as a powerful strategy to complement traditional ionic-type transformations.However,carbon-carbon cleavage reaction triggered by alkoxy radical intermediate derived from the combination of alkyl radical and dioxygen,is scarce and underdeveloped.Herein,we report alkoxy radical,which was generated from alkyl radical and dioxygen,mediated selective cleavage of unstrained carbon-carbon bond for the oxysulfonylation of 1,1-disubstituted alkenes,providing facile access to a variety of valuableβ-keto sulfones.Mechanistic experiments indicated alkoxy radical intermediate that underwent subsequent regioselectiveβ-scission might be involved in the reaction and preliminary computational studies were conducted to provide a detailed explanation on the regioselectivity of the C-C bond cleavage.Notably,the strategy was successfully applied for constructing uneasily obtained architecturally intriguing molecules.

NH4I-Catalyzed Synthesis of Sulfonamides from Arylsufonylhydrazides and Amines

A novel and efficient approach to sulfonamides has been developed. Using TBHP as the oxidant and NH4I （20 mol%） as the catalyst, arylsulfonyl hydrazides reacted with amines to provide sulfonamides in moderate to good yields. Possible reaction pathway for the formation of the products was also discussed in this paper.

Synthesis of 2-Amino-1,3,4-oxadiazoles through Elemental Sulfur Promoted Cyclization of Hydrazides with Isocyanides

A novel sulfur-promoted cyclization of hydrazides and isonitriles to produce 1,3,4-oxadiazole has been devel- oped. The method is operationally simple and compatible with a wide scope of substrates and various 2-amino- 1,3,4-oxadiazoles are efficiently obtained in good yields.

Palladium/Copper Cocatalyzed Coupling Reaction of Aroyl Hydrazides with Indoles

An unprecedented palladium/copper cocatalyzed coupling reaction of indoles with simple aroyl hydrazides has been developed under aerobic conditions. A range of aroyl hydrazides underwent palladium/copper cocatalyzed oxidative arylation with indoles open to air in a 1：1 mixture of dimethyl sulfoxide and nitromethane to give structurally diverse 2-arylindoles or 3-arylindoles in moderate to good yields. The reaction well tolerates a wide variety of functional groups such as alkoxy, halo, ester.

Palladium-catalyzed sulfonylative coupling of benzyl(allyl)carbonates with arylsulfonyl hydrazides

An efficient palladium-catalyzed sulfonylative coupling for the synthesis of benzyl(allyl)sulfones from sulfonyl hydrazides and carbonates was developed.The novel methodology employs easily accessible chemical feedstocks including stable and readily available arylsulfonyl hydrazides and benzyl(allyl)carbonates.A variety of benzyl(allyl)sulfones could be obtained in good to excellent yields in the presence of Pd(dppf)Cl2 without additional base under mild conditions.

Preparation of Peptide Selenoesters from Their Corresponding Acyl Hydrazides

Main observation and conclusion Selenoesters are useful substitutes for traditional thioesters in protein ligation chemistry due to their high reactivity in the trans-thio/selenoesterification reaction.However,existing synthetic routes to access peptide selenoester require a selenoesterification reaction between a selenide and a protected peptide with a free carboxylate at the C-terminus.

Substituent effects on novel lanthanide(Ⅲ) hydrazides complexes

New lanthanide(Eu3+ and Gd3+) complexes were successfully synthesized and the effect of the p-phe nyl substituent on the Eu3+luminescent properties was evaluated.In this sense,benzhydrazide,p-toluic hydrazide,4-hydroxybenzhydrazide and 4-aminobenzoic hydrazide were used as ligands and the complexes were obtained by mixing the lanthanide salts with hydrazides in ethanol at room temperature and keeping the reaction for 2 h under mechanical stirring.Crystal of Gd-amino was obtained and its structure was elucidated by single-crystal X-ray diffraction,revealing that Gd3+centered in a distorted tricapped trigonal-prismatic molecular geometry.IR spectroscopy and the elucidated structure confirm hydrazides acting as bidentate ligands binding to Ln3+ions through the oxygen of carbonyl group and the nitrogen of terminal amine,forming a five-membered ring,CHN analyses confirm the molecular formulas [Gd(amino)4(H2 O)](NO3)3·(C2 H5 OH) and [Eu(toluic)3(H2 O)3](NO3)3.Lower T1 state energies are observed for ligands p-substituted with higher electron donating capacity groups,such as p-NH2 and pOH.In contrast,higher lifetimes and quantum efficiencies are obtained for Eu3+complexes with ligands p-H and p-CH3 substituted,which are not deactivator groups.

Soluble Polymer Supported (Diacetoxy)iodobenzene in Synthesis

Polyethylene glycol (PEG) supported (diacetoxy)iodobenzene as soluble polymer reagent can smoothly oxidize acid hydrazides into corresponding dimmers in good yields under very mild conditions.

Simple and Efficient Synthesis of Novel Glycosyl Thiourea Derivatives Derived from Thiophene as Potential Antitumor Agents

The practical synthesis of pseudonucleosides incorporating thiourea derivative by coupling of monosaccharides （D-glucose and D-galactose） per-O-acetylated glycosyl isothiocyanates and different heterocyclic hydrazide derivatives is reported. The method involves the preparation ofper-O-acetylated glycosyl isothiocyanates from per-O-acetylated sugars （two-step synthesis）, which couple with heterocyclic hydrazides from amines to give thiourea-linked pseudonucleosides. All newly synthesized pseudo-nucleosides were assayed against human lung cancer-cell lines （PG） and human liver cancer-cell lines （BEL-7402） in vitro. The 6,6-dimethyl-benzothiophen-3-carbo-hydrazide-4-one pseudonucleosides showed moderate inhibition against these two cancer-cell lines with ECs0 from 22.8 to 76.4 mM and from 54.9 to 82.4 mM, respectively. And the other compounds did not demonstrate any significant cytotoxicity even at concentrations up to 200 mM.

A mild and facile method for one pot synthesis of 2,5-di-substituted 1,3,4-oxadiazoles at room temperature

2,5-Di-substituted 1,3,4-oxadiazoles 3a-n have been synthesized as a one pot procedure from the reaction of acid hydrazide 1, acyl halides 2 and phosphorus pentoxide in acetonitrile at room temperature. High yield, short reaction time （10-15 min）, mild condition, and easy work-up are advantages of this methodology.

Sensitive Colorimetric and Fluorescent Detection of Mercury Using Fluorescein Derivations

A colorimetric and fluorometric dual-model probe for mercury (II) ion was developed employing fluorescein hydrazide (FH) in ethanol-HEPES solution (1:1, v/v, pH 8.0). The probe exhibited high selectivity and sensitivity for Hg2+ detection using UV/Vis and fluorescence spectroscopy. Addition of Hg2+ caused a visual color change from colorless to coloured and a fluorescence change from colorless to bright green. Other metal ions did not interfere with the detection of Hg2+.

Design, Synthesis, Crystal Structure and Photophysical Properties of New Oxadiazole Extended Viologen Fluorophore

Viologens (N,N'-dimethyl-4,4-bipyridinium) are advanced functional materials, found important applications in electrochromic devices, molecular machines, organic batteries, and carbohydrate oxidation catalysts in alkaline fuel. In this article, we investigated the design, synthesis and photophysical properties of N,N'-dimethyl-2,5-Bis(pyridinium)oxadiazole 4 and its precursor 2,5- Bis(pyridine)oxadiazole 2. The crystal structure and photophysical properties of viologen 4 and precursor 2 have been determined. The viologen molecule 4 crystallized in monoclinic form, space group P21/n with four molecules in unit cell. Precursor molecule 2 also crystalized in monoclinic form, space group C2/c with four molecules in unit cell. From X-rd data, we found three cations in the molecular structure of viologen molecule 4, which is unusual in viologens. In the three-dimensional molecular packing diagram of molecule 4, the three cations and iodate anions are stabilized by C···C, C···I, N···I, N···H, H···I, N—H···I and C—H···I. The dihedral angle between planes having oxadiazole and two benzene rings are 5°and 8°, suggesting the molecule 4 is a slightly strained one. The molecular structure of precursor molecule 2 stabilized by C···C and N···H short contacts between the molecules. The molecule 4 displayed strong absorbance at 315 nm and emissions between 390 - 410 nm.

Synthesis and X-ray Crystal Structure of a New Manganese 18-Metallacrown-6

A new hexanuclear manganese (III) azametallacrown, [Mn6 (anhz)6 (DMF)2 (H2O)4]·8DMF was synthesized using trianionic pentadentate ligand, N-acetyl-3-hydroxy-2-naphthoic acid hydrazide (anhz3?), and characterized by X-ray single crystal diffraction. The deprotonated ligand bridges the metal ions using the N?N group of hydrazide to form an 18-membered-ring that has M?N?N repeating units and a cavity in the center. The stereochemistry of the compound has an alternating Δ/Λ propeller configuration. Key words azametallacrown - manganese - crystal structure - pentadentate - hydrazide - synthesis CLC number O 614.7 Foundation item: Supported by the National Natural Science Foundation of China (20171035), The Natural Science Foundation of Hubei ProvinceBiography: Han Dong-dong (1977-), female, Master, research direction: inorganic chemistry

Synthesis and Crystal Structure of N-(1-Phenyl-3methyl-4-benzal-pyrazolone-5)-furoic Hydrazide

N-(1-Phenyl-3-methyl-4-benzal-pyrazolone-5)-furoic hydrazide (PMBP-FUH, C22H18N4O3, CCDC No: 188946) has been synthesized and characterized by IR spectrum, 1H NMR and single-crystal X-ray diffraction. The crystal is of orthorhombic, space group Pbca with a = 11.870(2), b = 15.951(3), c = 19.674(3) ? V = 3725.0(11) ?, Mr = 386.40, Z = 8, Dc = 1.378 g/cm3, F(000) = 1616, R = 0.0455 and wR = 0.0809. The inter- or intramolecular hydrogen bonds result in the formation of three-dimensional network structure.

Yb(OTf)_3-catalyzed synthesis of pyrroles under solvent-free conditions

A Yb（OTf）3-catalyzed approach for the synthesis of pyrroles under solvent-free conditions was achieved, which could afford the desired products with yields ranged from moderate to excellent.

Crystal Structure of a Novel Compound: 1-Phenyl-3-ethyl-4-(salicylidene hydrazide)-propenylidene-pyrazolone-5

A novel compound PMPP-SAL （1-phenyl-3-methyl-4-（salicylidene hydrazide）- propenylidene-pyrazolone-5） has been synthesized and characterized by elemental analysis, IR,^1H NMR and single-crystal X-ray diffraction. The X-ray diffraction reveals that the compound is of orthorhombic, space group Pbca with a=16.132（5）, b=10.113（3）, c=23.143（7） A, V=3776（2）A°^3, Z=8, C20H20N4O3, Mr=364.40, Dc =1.282 g/cm^3, F（000）=1536,μ（MoKa）=0.089 mm^-1, S=0.992, R=0.0578 and wR=0.1362 for 1871 observed reflections with I〉2σ（I）. In the crystal, the compound possesses two C=O bonds and exists in the NH-form＇ other than NH-form.