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.

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.

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.

Syntheses, Structures and Antibacterial Activities of Two Nickel（Ⅱ） Complexes with N-Hexanoylsalicylhydrazide Ligand

The two trinuclear nickel（Ⅱ） complexes, Ni3（C13H15N2O3）2（C5H5N）4 （1） and Ni3（C13H15N2O3）2（C5H5N）2- （C3H7NO）2 （2）, were prepared by the reaction of Ni（OAc）2·4H2O with N-hexanoylsalicylhydrazide. The crystal structures of complexes were determined by X-ray diffraction analysis. Complex 1 takes triclinic symmetry with space group P-1 and cell dimensions of a=0.92377（2） nm, b= 1.08786（6） nm, c= 1.29391（3） nm, α=76.395（4）°, β=78.418（3）°, γ=67.378（4）°, V= 1.15772（7） nm^3, Z= 1,μ= 12.63 cm^-1. Complex 2 belongs to triclinic system and P2（1） space group and the crystallographic data： a= 1.4889（2） nm, b= 1.0389（1） nm, c= 1.4994（2） nm, β= 96.174（4）°, V=2.3058（5） nm^3, Z=2,μ= 12.70 cm^-1. The structures of the two molecules are similar. The three nickel atoms in each molecule of the two title complexes arrange in a strictly linear structure. The central nickel atom of the molecule adopts octahedral configuration, while the two nickel atoms on the two sides adopt square-planar configuration in each molecule. But the central nickel atoms of the two complexes have different axial ligands, which cause a slight difference in the bond distances of the octahedron. The antibacterial activity of compound 1 against seven common bacteria was investigated.

Synthesis, insecticidal activity and molecular docking study of clothianidin analogues with hydrazide group

A series of novel neonicotinoid analogues were designed and synthesized by introducing a hydrazide group into clothianidin. Their structures were confirmed by IR, 1H NMR, and HRMS （ESI）. Preliminary bioassay showed that some compounds, Sb and Sg, exhibited good activity against soybean aphids （Aphis glycines） at 100 mg L ^-1. In addition, molecular docking with receptor was carried out to explain their different activity from clothianidin.

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.

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.

Total synthesis of snake toxin α-bungarotoxin and its analogues by hydrazide-based native chemical ligation

Nicotinic acetylcholine receptors(nAChRs) play important roles in intercellular communications of nerve cells. α-Bungarotoxins(αBtx) is a moderator for the nAChRs. Chemical synthesis provides a promising way to access aBtx and their analogues. Here, we reported a new method for a-bungarotoxin by combining Fmoc-SPPS and peptide hydrazide based ligation strategy. The two-segment ligation method may enable efficient synthesis of aBtx analogues. These synthetic toxin peptides are useful tools for development of imaging or therapeutic reagents.

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.

Complexation of two non-fully hydrogen bonded aromatic hydrazide heptamers toward n-octyl-α-L-glucopyranoside in chloroform

Two aromatic hydrazide haptamers have been prepared,with both consisting of two hydrogen bonded folded segments. Compared to their fully hydrogen bonded analogues,the flexibility of their backbones increases due to lack of one or two intramolecular hydrogen bonds at the middle aromatic unit. (2D) 1H NMR,circular dichroism and fluorescent studies revealed that both oligomers moderately complex n-octyl-α-L-glucopyranoside in chloroform.

Novel 1,3,5-thiadiazine-2-thione derivatives containing a hydrazide moiety:Design, synthesis and bioactive evaluation against phytopathogenic fungi in vitro and in vivo

A series of novel 1,3,5-thiadiazine-2-thione derivatives bearing a hydrazide moiety were designed, synthesized and evaluated for their antifungal activities against Rhizoctonia solani (Rs), Fusarium graminearum (Fg), Botrytis cinerea (Bc) and Colletotrichum capsici (Cc). The in vitro antifungal bioassays indicated that most of title compounds displayed good selectivity and specificity aganist Rs relative to Fg, Bc and Cc. Strikingly, the title compound N'-(4-chlorophenyl)-2-(5-phenyl-6-thioxo-1,3,5-thiadiazinan-3-yl)acethydrazide (5b) obviously inhibited the Rs growth in vitro with the EC50 value of 0.24μg/mL, which is approximately 2-folds more effective than the commercialized fungicide carbendazim (0.55 μg/mL). The in vivo anti-Rs effects of title compound 5b were further evaluated on rice leaves with control efficacies of 98.58% at 200 μg/mL and 61.27% at 100 μg/mL. The above researches provide a significant reference for the further structural optimization of 1,3,5-thiadiazine-2-thione derivatives bearing a hydrazide moiety as potential fungicides.

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.

Synthesis, Antimicrobial Activity, and Molecular Docking of Benzoic Hydrazide or Amide Derivatives Containing a 1,2,3-Triazole Group as Potential SDH Inhibitors

The present study was carried out in an attempt to synthesize a new class of antimicrobial agents containing a 1,2,3-triazole motif formed by classical copper catalyzed click chemistry.Antifungal bioassay results showed that five compounds 5a;5e,5h,5j,and 5k possessed a remarkable growth inhibitory activity against Botryosphaeria dothidea,Rhizoctonia solani and Gibberella zeae with EC_(50) values within 10.0-0.306μg/mL.The in vitro efficacy was better than those of the commercial agrochemicals Azoxystrobin,Boscalid,and Fluxapyroxad.In vivo trials showed that compound 51 was effective for the control of rice sheath blight and wheat scab with the effects of 75% and 95%,respectively.Antifungal mechanism studies suggested that target compounds were potential succinate dehydrogenase inhibitors(SDHIs),which were proposed by the agreeable molecular docking study and restrained SDH activity(IC_(50)=3.95 μg/mL,51).Interestingly,compounds 5r and 5s displayed good antibacterial activity against phytopathogens.In vivo screening of 5r and 5s against rice bacterial blight afforded a superior control effect(up to 51%)than those of commercial agents Bismerthiazol and Thiodiazole copper.The current studies could support some title compounds to be the lead compounds for exploring highly bioactive antimicrobial substrates,particularly the potential SDHIs.

Asymmetric Direct Aldol Reaction of Cyclohexanone Catalyzed by （ N＇-BenzyI-N＇-D-prolyl）-trans-4- hydroxy-L-proline Hydrazide

A new proline catalyst, namely （N＇-benzyl-N＇-D-prolyl）-trans-4-hydroxy-L-proline hydrazide, has been prepared and proved to be a superior catalyst for the asymmetric aldol reaction of cyclohexanone and aromatic aldehydes, affording up to 98 ： 2 dr and 98% ee.

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.

Antibacterial Activity of Novel 18β-Glycyrrhetinic Hydrazide or Amide Derivatives

Through a facile structural modification on the natural bioactive ingredient 18β-glycyrrhetinic acid(GA),a series of novel GA hydrazide or amide derivatives was obtained,and their final molecular frameworks were characterized by NMR and HRMS analysis.Antibacterial bioassays revealed that some of the GA hydrazide or amide derivatives were able to suppress the growth of three tested plant pathogens.Particularly,compound 3c exhibited excellent in vitro activity against Xanthomonas oryzae pv.Oryzae(Xoo),Pseudomonas syringae pv.actinidiae(Psa),and Xanthomonas axonopodis pv.citri(Xac),providing the EC_(50) values of 5.89,16.1,and 3.64µg/mL,respectively.The data were better than those of the positive controls thiodiazole copper(92.7,77.8,and 89.9µg/mL,respectively)and bismerthiazol(31.1,125.6,and 77.4µg/mL,respectively).In addition,in vivo experiments suggested that,compared with thiodiazole copper(41.93%and 39.73%,respectively),compound 3c exerted prominently curative and protective activities against rice bacterial leaf blight at 200µg/mL with the control effects of 52.36%and 51.40%,respectively.Given these obtained results,GA hydrazide or amide derivatives could serve as the feasible leads for exploring highly bioactive substrates.

Total synthesis of TRADD death domain with arginine N-GlcNAcylation by hydrazide-based native chemical ligation

TNFR1-associated death domain protein(TRADD)with arginine N-GlcNAcylation is a novel and structurally unique posttranslational modification(PTM)glycoprotein that blocks the formation of death-inducing signaling complex(DISC),orchestrating host nuclear factorκB(NF-κB)signaling in entero-pathogenic Escherichia coli(EPEC)-infected cells.This particular glycosylated modification plays an extremely vital role for the effective colonization and pathogenesis of pathogens in the gut.Herein we describe the total synthesis of TRADD death domain(residues 195-312)with arginine235 NGlcNAcylation(Arg-GIcNAc TRADD(195-312)).Two longish peptidyl fragments of the wild-type primary sequence were obtained by robust,microwave-assisted,highly efficient,solid-phase peptide synthesis(SPPS),the N-GlcNAcylated sector was built by total synthesis and attached specifically to resinbound peptide with an unprotected ornithine residue via silver-promoted on-resin guanidinylation,ArgGlcNAc TRADD(195-312)was constructed by hydrazide-based native chemical ligation(NCL).The facile synthetic strategy is expected to be generally applicable for the rapid synthesis of other proteins with Arg-GIcNAc modification and to pave the way for the related chemically biological study.

Transition Metal Free Chemoselective Reduction ofα,β-Unsaturated Ketones to Saturated Ketones Using Tosyl Hydrazide as a Hydrogen Donor

An efficient,inexpensive and simple method for the reduction of variousα,β-unsaturated ketones to corre-sponding saturated ketones using tosyl hydrazide as a hydrogen donor in DMF using calcium oxide powder has been reported.A variety of enones underwent reduction without forming undesirable side products.High chemose-lectivity,broad functional group tolerance and good yields are the noteworthy features of this protocol.

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.

Synthesis and Antibacterial Activities of N- [（1-Aryl-3-phenyl-pyrazol- 4-yl）methylene]-2-（halo-o-hydroxyphenyl）hydrazide Derivatives

A series of novel N-[（1-aryl-3-phenyl-pyrazol-4-yl）methylene]-2-（halo-o-hydroxyphenyl）hydrazide derivatives was synthesized and the antibacterial activity of each of them was evaluated. The supposed reaction mechanism of acquiring compounds 3a--3d is that catalytic activity is enhanced by the electron-donating groups of the first phenyl ring while decreased by electron-withdrawing groups of that ring. The result of preliminary bioassay shows that the lowest minimal inhibitory concentration（MIC） of the title compounds against Escherichia coli is 2 ℃g/mL. MIC values against Monilia albiean and Staphloeoeeus aureus are as low as 4 ~g/mL. They will be a series of potential antibacterial compounds against fungi and gram-negative bacteria.