FREE RADICAL RING OPENING POLYMERIZATION OF CYCLIC ACRYLATES

Cyclic acrylates, 2,2- dimethyl-5-methylene-1 , 3-dioxolan-4 -one and 2- phenyl-5-methylene-1,3-dioxolan-4-one, were synthesized successfully. The monomers were characterized by ~1H NMR, ~(13)C NMR, IR and elemental analysis or HRMS. Polymerization of the monomers were carried out at 120℃with di-t-butylperoxide as initiator. The polymers were studied by ~1H NMR, ~(13)C NMR, UV and hydrolysis. The molecular weights of the resulting polymers were estimated by viscosity measurement and the extent of ring opening was estimated also by ~1H NMR and hydrolysis of the polymers and further confirmed by UV spectra.     

SYNTHESIS AND POLYMERIZATION OF 2-OXO-3-METHYLENE-1,4-DIOXANES

A new kind of monomers was successfully synthesized by the reaction between 2-chloro methyl cycloketal and trimethylsilyl cyanide, followed by ring closure and dehaiogenation. Polymerizations of the monomers were carried out in benzene solution at 80℃with benzoyl peroxide as initiator. Both the structures of monomers and polymers were characterized by IR, ~1H NMR, ~(13)C NMR and elemental analysis.     

Synthesis of novel copolymer：Poly(p-dioxanone-co-L-phenylalanine)

In order to expand the application of poly(p-dioxanone) or PPDO in biomedical area,a series of novel copolymers were synthesized successfully by one-step,melted copolymerization of p-dioxanone(PDO) and L-phenylalanine N-carboxyanhydride(L-Phe-NCA) monomers.With the in-feed molar ratio of L-PheNCA /PDO equal to 1/20,the conversions of the two kinds of monomers were calculated from ~1H NMR. The average molecular weight and polydispersity of the copolymer increase with the increasing reaction time and catalyst concentration.However,the conversions of the two kinds of monomers did not change with the reaction conditions.A three-step mechanism is presented and proved by high resolution ~1H NMR and IR spectrums.     

Antiviral stereoisomers of 3,5-bis(2-hydroxybut-3-en-1-yl)-1,2, 4-thiadiazole from the roots of Isatis indigotica

Four stereoisomers of 3,5-bis(2-hydroxybut-3-en-1-yl)-1,2,4-thiadiazole, named insatindigothiadiazoles A–D(1a–1d), were isolated from the roots of Isatis indigotica. Their structures were determined by spectroscopic analysis; specifically, the absolute configurations were assigned by using the MPA determination rule based on Δδ~(RS)values of MPA esters, and supported by electronic CD(ECD)calculations. Proposed biosynthetic pathways and preliminary investigations of the biological activities of 1a–1d against influenza virus A(H3N2), Coxsackie virus B3, and/or HSV-1 are also discussed.     

Synthesis and activities of new 4-hydroxy benzoxazolone derivatives

<正>A series of new 4-substituted benzoxazolone derivatives were synthesized according to a convenient method,their anti-inflammatory and analgesic activities in vivo were evaluated.All of them were new compounds,the structures of all the synthesized compounds were confirmed by ~1H NMR,~(13)C NMR,ESI-MS and HR-MS.Most of the compounds exhibited anti-inflammatory activity.     

POLYMERIZATION OF ETHYLENE METHYL PHOSPHATE IN THE PRESENCE OF SODIUM POLY(ETHYLENE GLYCOL)ATE*

Poly(ethylene methyl phosphate)-poly(ethylene glycol)-poly(ethylene methyl phosphate) triblockcopolymers carrying hydroxyl group at both chain ends were synthesized with sodium poly(ethyleneglycol)ate as initiator. The effects of the factors such as solvent, amount of the initiator and reaction timewere investigated. The copolymers were characterized by IR, ~1H-NMR, ~1H{~(31)P}-NMR, ~(13)C-NMR, ~(31)P{~1H}-NMR, and DSC. High molecular weight of the copolymer and high yield of the polymerization were achievedwithin 3 min at 25℃. The polymerization process was studied by ~(31)P{~1H}-NMR and transesterification wasfound during longer polymerization time.     

ESTIMATION OF REACTIVITY RATIOS OF METHYL ACRYLATE WITH N-ARYLMETHACRYL-AMIDE COPOLYMERS BY ~1H NMR METHOD

The copolymerizations of methyl acrylate (MA) with different N- arylmethacrylamide (N-ArMA) were carried out in benzene solution by free radical initiation. The compositions of the copolymers were deter mined by ~1H NMR method. The monomer reactivity ratios were calculated by the Fineman-Ross (F-R) method. The reactivity ratios and the activity of various N-ArMA with MA were investigated.     

A novel efficient synthetic method for 2,2′,3,3′-biphenyltetracarboxylic dianhydride

A novel approach to the synthesis of 2,2′,3,3′-biphenyltetracarboxylic dianhydride is described.The target compound was prepared by a nickel-catalyzed coupling reaction of dimethy 3-chlorophthalate(3-DMCP) for 4 h at 70-80℃,followed by subsequent hydrolysis of tetra-ester in acid solution and dehydration of tetra-acid,with overall yield of 68%.The structures of the products were characterized by IR,~1H NMR and ~(13)C NMR respectively.     

THE SYNTHESIS AND STRUCTURE OF 4,5-DIOXO-2-THIO-1,3,2,4-DIAZADIPHOSPHOLANES

A new type of diphosphorus heterocycles, 4,5- dioxo- 2- thio- 1,3, 2,4- diazadiphospholanes,has been synthesized by the condensation of carbamyl phosphoryl amidate and 4- substitutedphenyl phosphine dichloride, and then sulfurization. The cis- and trans-isomers of the com-pounds were separated by HPLC, and their structures were studied with ~1H NMR and ~(31)PNMR. It has been found that the cis- and trans-isomers have different chemical shifts (δ) anddifferent coupling constants. The preliminary bioassay shows that some of them possessstrong herbicidal activity.     

TWO NEW CINNAMIC ACID DERIVATIVES FROM MAGNOLIA BIONDII PAMP

Two new cinnamic acid derivatives named biondinin C and biondinin D were isolated from the flower buds of Magnolia biondii pamp. The structures were elucidated by the spectral data including ~1H, ~1H COSY, ~1H-~(13)C COSY spectra.     

Synthesis and antifungal activity of trichodermin derivatives

<正>A series of derivatives were synthesized from trichodermin(1) which was an antifungal metabolite produced by Trichoderma taxi sp.nov.Their structures were confirmed by ~1H NMR,MS spectrum.Their antifungal activities were evaluated in vitro.The preliminary structure activity relationships(SAR) results indicated that the double bond,epoxide moiety and ester group were main pharmacophore elements,the stereochemistry of C4 position played a key role as well,and the compounds 1e-1g displayed stronger antifungal activity against Magnaporthe grisea than 1.     

SYNTHESIS AND POLYMERIZATION OF 2-OXO-3-METHYLENE-5, 6-DIPHENYL-1,4-DIOXAN

A new cyclic monomer, 2-oxo-3-methylene-5, 6-diphenyl-1, 4-dioxan, was synthesized. Thestructure of the intermediates and the monomer were determined by IR,~1H NMR,~(13)C NMR andelemental analysis. This new monomer is different from other cyclic monomers in this series,it isa solid (mp 108--109℃)and not very reactive, but still can undergo free radical ring-openingpolymerization. The free radical polymerization was carried out at 130℃. The structure of theresulting polymer was discussed and charaterized by IR, ~1H NMR, ~(13)C NMR and elementalanalysis. The molecular weight of the polymer was estimated by viscosity determination.     

8-O-4’ Neolignan glycosides from the aerial parts of Matteuccia struthiopteris

Two new 8-O-4’ neolignan glycosides, named matteustruthiosides A(1) and B(2) were isolated from the aerial parts of Matteuccia struthiopteris. Their chemical structures were characterized on the basis of various spectroscopic techniques. The absolute configurations of them were determined by experimental circular dichroism(CD) spectra. Compounds 1 and 2 were inactive against influenza A(H1N1) virus in vitro.     

Synthesis of Thiourea Derivatives on Soluble Polymeric Support

A modified poly(ethylene glycol) (PEG) has been developed as the soluble polymeric supports for liquid phase synthesis of novel thiourea derivatives.In each step of the sequence,the PEG-bound products were precipitated in cold Et2O and the unreacted materials and by-products were removed by simple filtration.The progress of reaction,purity of the isolation and the structure of the PEG-bound products were easily monitored by TLC,IR and ^1H NMR spectra.Representative thiourea derivatives were obtained in moderate yields with excellent purity from this modified PEG-bound product by the cleavage with 50% TFA/H2O.     

Synthesis and characterization of trimethoxysilyl-functionalized poly(phthalazinone ether ketone)

A novel alkoxysilyl-functionalized poly(phthalazinone ether ketone)(PPEK)was prepared for the boundary lubricant application in micro-electro-mechanical system(MEMS).The synthesis of functionalized PPEK was started from the hydro- xylation of PPEK,then following with the corresponding ring-opening reaction of 3-glycidoxypropyltrimethoxysilane(GPTMS). The structures of the functional PPEK were confirmed by FTIR,~1H NMR,~(29)Si NMR,and UV-vis spectrum.     

Prenylated flavonoids from Tephrosia apollinea

In continuation of our chemical investigation on some medicinal plants of the genus Tephrosia,re-investigation of the methylenechloride/methanol(1:1) extract of the air-dried aerial part of Tephrosia apollinea afforded a new prenylated flavonoid 1, in addition to an aromatic ester,a sesquiterpene,a lignan and several known prenylated flavonoids.The structures were established by(~1H NMR,~(13)C NMR,DEPT,~1H-~1H COSY,HMQC,HMBC,NOESY and HRMS).Relative configurations of 9 and 10 were confirmed by X-ray anal...     

NMR STUDIES ON POLYETHER-POLYURETHANE ZWITTERIONOMERS——CHAIN STRUCTURE AND PHASE SEPARATION

The ~1H and ~(13)C NMR spectra of polyether-polyurethancs (A) based on 4, 4'-diphenylmethanediisocyanate (MDI), N-methyl diethanolamine (MDEA), and polytetramethyleneoxide (PTMO)and the zwitterionomers derived from A with various degree of ionization was assigned by comparingwith model compounds. Phase separation of the samples was visualized through pulsed NMR investigations. The FIDsignals of these multiphase elastomers were recorded and decomposed by non-linear least squaresregression into fast Gaussian and slow exponential components assodated with the hard, the soft andthe interface respectively. Thus pulsed NMR gives both qualitative and quantitative informationabout the existence of multiphases and the relative amounts of materials in each phase.     

Design and synthesis of novel triazole derivatives containing γ-lactam as potential antifungal agents

A series of novel triazole derivatives containing γ-lactam were designed and synthesized, and their structures were confirmed by ~1H NMR,~(13)CNMR and HRMS. The in vitro antifungal activities of the target compounds were evaluated. The results showed that all of the compounds exhibited stronger activity against the six clinically important fungi tested than fluconazole. 3D and 3E showed comparative activity against the fungi tested except for Candida glabrata and Aspergillus fumigatus as voriconazole. In addition,the docking model for 2A and CYP51 was investigated.     

Synthesis and characterization of imide modified poly(dimethylsiloxane) with maleopimaric acid as raw material

With the natural rosin derivative(maleopimaric acid,MPA) as the raw material,imide modified vinyl poly(dimethylsiloxane)(MP-VMS) was synthesized and characterized by ~1H NMR and ~(13)C NMR.The curing kinetic parameters of MP-VMS were determined by differential scanning calorimetry(DSC) at various heating rates(5,8,10,15 ℃/min) from the Kissingner.Ozawa and Crane methods.The activation energy(E_α),pre-exponential factor(A) and reaction order(n) were respectively 18.6 kJ/mol,71,108 and0.902.The low-temperature and high-temperature resistance of its curing product were respectively investigated by DSC and thermogravimetric analysis.The results showed that incorporation of MPA could significantly improve the thermal stability of silicone while had no effect on the low-temperature resistance,and the T_(max)(the temperature corresponding to the maximum weight loss rate) increased by 70.7 C.     

TEUPERNIN A,B AND C,THREE ENT-CLERODANE DITERPENOIDS FROM TEUCRIUM PERNYI FRANCH

Three furanoid ent-clerodane diterpenoids,teupernin A,B and Chave been isolated from the acetone extract of Teucrium pernyi Franch.Theirstructures were established by spectroscopic means(UV,IR,MS,~1H NMR,~(13)CNMR,H-H COSY,C-H COSY and NOE)and by comparison with related compounds.