SYNTHESIS AND PROPERTIES OF TWO POLY(PHENYL METHACYLATE)S FUNCTIONALIZED WITH PEDENT DIHYDROPYRIMID(THI)ONE GROUPS

New polymers with functionalized dihydropyrimidones were synthesized.The methacryloyl chloride was first reacted with 4-hydroxybenzaldehyde,and the affording aldehyde was upon the one-pot Biginelli reaction to afford new monomers with dihydropyrimidone as pending groups (M1,M2).Two new monomers were polymerized via radical polymerization to afford interesting color changeable polymers in different pH.The polymers were characterized by ~1H-NMR and IR methods.The color changeable properties were also inves...     

A NEW FACILE METHOD FOR THE SYNTHESIS OF AZACROWN ETHERS BY USING BENZYLSULFONAMIDE AS A SOURCE OF NITROGEN

Benzylsulfonamide was used as a source of nitrogen in the syn-thesis of azacrown ethers,and the cyclic intermediates were easily deben-zylsulfonylated by treating with CaF_2/H_2SO_4 to afford the azacrown ethers.     

A New Synthetic Method of Highly Substituted Cyclopentadienes from α,β-Unsaturated Alkynones

Promoted by samarium diiodlde in THF, the α, β-unsaturated alkynones were reduced to afford intermolecular reductive cou-pling products. The multiply substituted cyclopentadienes were prepared conveniently in good yields.     

A Novel Preparation Method of C-Terminal Glutamine Dipeptides

A novel synthesis method of dipeptides containing glutamine is reported. Protected L-amino acids were prepared by using inexpensive phthaloyl as the protecting group. Then the phthaloyl-L-amino acids were condensed with glutamine salts by the mixed anhydride method to afford phthaloyl dipeptides. Subsequently, the phthaloyl was removed from the dipeptides with hydrazine hydrate. As a result, optically pure glutamine-containing dipeptides were obtained in good yields.     

（Z）—α—Selanyl Alkenyl grignard Reagents as Convenient Precursors for Stereose

（Z）-α-Selanyl alkenyl Grignard reagents 2 were prepared conveniently by treatment of α-bromovinylselenides 1 with magnesium filings in THE Intermediates 2 were reacted with alkyl iodides in the presence of Cul or Pd(PPh3)4 to afford(Z)-1,2-disubstituted vinylselenides 3,which were cross-coupled with Grignard reagents in the presence of (PPh3)2NiCl2 to give trisubstituted alkenes 4 stereoselectively in good yields.     

Direct Iodination of Aromatic Compounds with Polyvinylpyrrolidone Supported Hydrogen Peroxide (PVP-H2O2) and Potassium Iodide or Molecular Iodine

Hydrogen peroxide was supported on polyvinylpyrrolidone to afford a stable and mild oxidizing reagent.Acti-vated aromatic compounds were reacted with PVP-H_2O_2 in the presence of KI or I_2 and a catalytic amount ofH_3PW_(12)O_(40)in refluxing CH_2Cl_2 to afford the corresponding iodinated arenes.     

利用脱镁叶绿酸甲酯的化学修饰合成红紫素酰亚胺衍生物

A series of novel purpurin-18 imide derivatives exhibiting long wavelength absorption and amphiphilicity wereobtained from methyl pheophorbide-a(MPa)by modification of the peripheral functional groups.The vinyl groupat 3-position was oxidized with OsO_4 and NaIO_4 to form the formyl group and the Grignard reaction of this alde-hyde with the alkyl magnesium bromide was carried out to give the corresponding 3-(1-hydroxylalkyl)pheophor-bide-a.The E-ring of these chlorines was converted into anhydride ring to give purpurin derivatives by air oxidation.The trans-3~2-alkyl purpurin derivatives were obtained by dehydration of hydroxyl group at 3~1-position.TheN-hydroxyl purpurin imide was generated by treatment of the anhydride ring with bydroxylamine hydrochloride.The 3~1-alkylacyl-N-hydroxyl purpurin imides were obtained by oxidation of hydroxyl group at 3~1-position.Theacylation of N-hydroxyl group was completed to afford N-acyloxy purpurin imides.The photocytoxicity of severalcompounds in vitro were tested.     

Preparation and Enantioseparation Property of Chiral Stationary Phases Based on Cellulose Tris(3,5-dimethylbenzoate)——A New Way to Prepare Polysaccharide-coating Type Chiral Stationary Phases

A new method to prepare polysaccharide-coating type chiral stationary phases （CSPs） was developed in this work. As a typical example, naked silica gel was coated by cellulose, which was then derivatized with 3,5-dimethylbenzoyl chloride to afford cellulose tris（3,5-dimethylbenzoate）-silica gel （CTDBS） complex. The silanols on CTDBS were end-capped with 3- aminopropyltriethoxysilane to obtain CSP 1. The amino groups on CSP 1 were further end-capped with 3,5-dimethylbenzoyl chloride to give CSP 2. The silanols on CTDBS were end-capped with methyltrimethoxysilane to yield CSP 3. CSPs 1-3 were characterized by FTIR, solid-state 13C-NMR and elemental analysis. The enantioseparation abilities of CSPs 1-3 were evaluated with structurally various chiral analytes. The enantioseparation results demonstrated that the end-capping moieties on CSPs 1 and 2 significantly affected enantioseparation. In addition, the effect of the structures of chiral analytes and end- capping moieties on the retention factors and the resolutions was discussed.     

Design,synthesis and preliminary bio-evaluation of glucose-cholesterol derivatives as ligands for brain targeting liposomes

A series of glucose-cholesterol derivatives 8a-8e as ligands for brain targeting liposomes were synthesized.The preparation of compound 6 involved temporary protection of glucose with chlorotrimethylsilicane and hexamethyldisilazane followed by selectively hydrolyzed.The known cholesteryl tosylate 1 were coupled to ethylene glycols to afford alcohol 2a-2e.Substitution and deprotection of alcohol 2a-2e furnished the acids 4a-4e,which was condensed with compound 6 to get compounds 7a-7e,and then was deprotected in tetrahydrofuran with TFA to obtain the title compounds.As a model drug,tegafur was entrapped by liposomes coupled with 8b,and preliminary in vivo evaluation shown 8b could enhance the ability of liposomes delivering tegafur across the blood brain barrier.     

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.     

Convenient synthesis of some optically active 1,4-benzodiazepin-2,5-diones

Isatoic anhydride was reacted with several L-amino acids to give the corresponding （2S）-N-（o-aminobenzoyl）-2-alkylaminoacetic acids. The latter compounds were treated with phosphoryl chloride under reflux temperature to afford the cyclized products, （3S）-3-alkyl-3,4-dihydro- 1 H- 1,4-benzodiazepin-2,5-diones. 2007 M. Bakavoli. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.     

Ytterbium triflate hydrate catalyzed Michael addition and cyclocondensation of α,β-unsaturated ketones with active methylene compounds

Catalyzed by ytterbium（III） triflate hydrate [Yb（OTf）3.xH20], the Michael addition and cyclocondensation of α,β-unsaturated ketones with active methylene compounds to afford the 1,4-adducts and benzo[b]pyran derivatives, respectively were studied.     

Dinuclear Nickel(Ⅱ) Chlorides Bearing N,N′-bis(5,6,7-trihydroquinolin-8-ylidene)-[1,1′-biphenyl]-4,4′-diamines: Synthesis and Ethylene Polymerization

5,6,7-Trihydroquinolin-8-one was condensed with the corresponding benzidine to give N,N′-bis(5,6,7-trihydroquinolin-8-ylidene)-[1,1′-biphenyl]-4,4′-diamine derivatives(L1–L3). The ligands were reacted with two equivalents of Ni Cl_2·6H_2O in a mixture of Et OH and CH_2Cl_2 to afford the corresponding dinickel(II) chloride complexes(Ni1-Ni3). The organic compounds were completely characterized, whilst the bi-metallic complexes were characterized by FTIR spectra and elemental analysis. These nickel complexes exhibited high activities towards ethylene polymerization in the presence of either MAO or Me_2AlCl, maintaining a high activity over a prolonged period. The obtained polyethylenes were confirmed as having low molecular weights by GPC analysis.     

Studies on Agarofurans V. Studies on the Reductive Ring-Opening of 3,4-Epoxide of Agarofurans

The nature of reductive ring-opening of epoxide has been widely studied. But epoxides of agarofurans with rigid skeleton have their own specificity. Agarofurans have been found to be active on the nervous system in our institute. Reduction of epoxides may afford different types of agarofurans. This prompted us to investigate the reaction.Epoxides 1, 2, 3 were prepared by oxidation of their corresponding olefins1. Generally, the nature of the reduction of epoxides with LAH depends on the ster…     

Synthesis and reactions of some 6-aryl and 2,6-diaryl-4-(4''''-antipyrinyl)-2,3,4,5-tetrahydropyridasin-3-ones and screening for their antibacterial activities

Some new pyridazinone derivatives(3) were synthesized through addition of antipyrin to β-aroylacrylic acids (1) followed by cyclization of the adducts. Reactions of 3 with ethyl bromoacetate,benzenesulfonyl chloride, benzoyl chloride and POCl_3 give N-substituted products and monochlorosub-stituted pyridazines (4), respectively. The reactions of the latter with thiourea give unexpected dithio-derivatives(5), which react with phenylhydrazine to give pyrazolopyridazino pyridazine derivatives (6).Reactions of 2 with NH_2OH in ethanol and pyridine afford oxime and oxazinone derivatives 7 and 8,tespectively. The antibacterial activities of several compounds were screened.     

Synthesis and Characterization of Dinuclear Aluminum Complexes Bearing N,N-Dialkylaniline-amido Ligands and Its Catalytic Properties for Lactone Polymerization

Two ligands [ortho-C6H4NR2（CH2NH）]2CH2CH2（3： R=Me; 4： R=EO were prepared by the reduction of preligands [ortho-C6H4NR2（CH=N）]zCH2CH2（1： R=Me; 2： R=Et）. These ligands reacted with AIMe3 to afford the corresponding dinuclear aluminum complexes {A1Me2[ortho-C6H4NR2（CH2N）]}2CHzCH2（5： R=Me; 6： R=Et）. All the compounds were characterized by 1H and UC nuclear magnetic resonance（NMR） spectroscopies and elemental analyses. The catalytic properties of the aluminum complexes towards the ring-opening polymerization of lactones were investi- gated in the presence of benzvl alcohol. All the oolvmerization reactions were proceeded in a controlled manner.     

2-FURFURYLKETONES FROM 2-(CHLOROMETHYL)FURAN AND LITHIUM TRIALKYLALKYNYLBORATES

2-(Chloromethyl)furan as an electrophile attacks lithiumtrialkylalkynylborates,followed by the oxidation with H_2O_2 under basicconditions to afford 2-furfurylketones in good yields.     

Regioselective Propargylation of Aldehydes with Propargyl Bromide Mediated by Sn-In in Aqueous Media under Microwave Irradiation

Tin-indium were employed in the propargylations of various aldehydes with propargyl bromide in the presence of SnCl2 and C6H5（CH3）3NBr under microwave irradiation to afford the corresponding homopropargyl alcohols exclusively in high yields. All the reactions were completed smoothly in predominantly aqueous media in 200 seconds only.     

A facile pathway to 2-furfurylketones

2-(Chloromethyl)furan as an electrophile reacted with lithium trialkylalkyllylbo-rates,followcl by the oxidation with H_2O_2 under basic condition to afford 2-furfurylketonesin good yields.This provides a new method for the preparation of 2-furfurylkctoncs.     

Cu（OAc）2 catalyzed Sonogashira cross-coupling reaction in amines

A simple Cu(OAc)_2 catalyzed Sonogashira coupling protocol is presented.It was found that the couplings of a variety of aryl halides with terminal alkynes were conducted smoothly to afford the corresponding desired products in moderate to excellent yields,using Cu(OAc)_2 as the catalyst and Et3N as the solvent.