RING-OPENING POLYMERIZATION OF l,4-DIOXAN-2-ONE INITIATED BY LANTHANUM TRIS(2,6-DI-TERT-BUTYL-4-METHYLPHENOLATE)

The ring-opening polymerization of 1,4-dioxan-2-one （PDO） was carried out by lanthanum tris（2,6-di-tert-butyl-4- methylphenolate） （La（OAr）3） as novel single component initiaLor. The influences of polymerization reaction temperature and the molar ratio of monomer to initiator on the monomer conversion and molecular weight of poly（1,4-dioxan-2-one） （PPDO） were explored. PPDO with high viscosity average molecular weight of 1.95×10^5 can be prepared at 40℃ when [PDO]/ [La（OAr）3] molar ratio was 800. Mechanism investigation shows that the polymerization proceeds through a ＂coordination- insertion＂ mechanism with selective rupture of acyl-oxygen be,nd of PDO.

SINGLE LANTHANUM TRIS(N-PHENYLETHYL-3,5-DI-t-BUTYLSALICYLALDIMINATO)S INITIATOR FOR RING-OPENING POLYMERIZATION OF 1,4-DIOXAN-2-ONE IN BULK

A rare earth Schiff base complex:lanthanum tris(N-phenylethyl-3,5-di-t-butylsalicylaldiminato)s [La(OPEBS)_3] was successfully applied as single component initiator for the ring-opening polymerization of 1,4-dioxan-2-one (PDO) in bulk.The influence of reaction conditions,such as polymerization temperature,the molar ratio of the monomer to initiator (M/I) on the monomer conversion and molecular weight of the polymer has been investigated.Poly(1,4-dioxan-2-one) with a viscosity-average molecular weight (My) o...

Synthesis, Structural Characterization and Antimicrobial Activity of a Novel Cobalt(II) Complex Based on 3-Methyl-1-Phenyl-4-(2-Thienoyl)-Pyrazol-5-One

New cobalt(II) complex, [Co(O2C15H11N2S)2(OH2)2]∙2H2O (1∙2H2O), has been synthesized upon reaction of cobalt chloride hexahydrate (Co(Cl)2∙6H2O) with 3-methyl-1-Phenyl-4-(2-thienoyl)-pyrazol-5-one (referred as HL) in ethanol at room temperature. Single crystal X-ray diffraction (XRD), spectroscopic methods, and microelemental analyses were used to characterize 1∙2H2O. Compound 1∙2H2O crystallizes in the orthorhombic crystal system with a Pbca space group and with the cobalt atom being pseudo-octahedral coordinated. The broth microdilution technique was used to screen the free ligand (HL) and the complex (1∙2H2O) for antimicrobial activities. HL has a low activity (MIC > 100 μg/mL) on all microorganisms, whereas compound 1∙2H2O displayed moderate activity (10 ∙2H2O exhibited bactericidal and fungicidal activity respectively on all the bacteria and yeasts tested. These findings reveal that the antimicrobial activity of HL was enhanced upon coordination to Co(II) ion against all microorganisms (bacteria and fungus).

Synthesis, Structural Characterization and Antimicrobial Activity of a Novel Cobalt(II) Complex Based on 3-Methyl-1-Phenyl-4-(2-Thienoyl)-Pyrazol-5-One

New cobalt(II) complex, [Co(O2C15H11N2S)2(OH2)2]∙2H2O (1∙2H2O), has been synthesized upon reaction of cobalt chloride hexahydrate (Co(Cl)2∙6H2O) with 3-methyl-1-Phenyl-4-(2-thienoyl)-pyrazol-5-one (referred as HL) in ethanol at room temperature. Single crystal X-ray diffraction (XRD), spectroscopic methods, and microelemental analyses were used to characterize 1∙2H2O. Compound 1∙2H2O crystallizes in the orthorhombic crystal system with a Pbca space group and with the cobalt atom being pseudo-octahedral coordinated. The broth microdilution technique was used to screen the free ligand (HL) and the complex (1∙2H2O) for antimicrobial activities. HL has a low activity (MIC > 100 μg/mL) on all microorganisms, whereas compound 1∙2H2O displayed moderate activity (10 ∙2H2O exhibited bactericidal and fungicidal activity respectively on all the bacteria and yeasts tested. These findings reveal that the antimicrobial activity of HL was enhanced upon coordination to Co(II) ion against all microorganisms (bacteria and fungus).

Synthesis of some new 3-[5-(2-oxo-2H-3-chromenyl)-1,3-oxazol-2-yl]-1,3-thiazolan-4-ones as antimicrobials

A series of some new 2-imino-5-[（Z）-1-（4-methylphenyl）methylidene]-3-[5-（2-oxo-2H-3-chromenyl）-1,3-oxazol-2-yl]-1,3- thiazolan-4-ones 5a-j has been synthesized and assayed for their antibacterial activity against Gram-positive bacteria viz.Bacillus subtilis（ATCC 6633）,Staphylococcus aureus（ATCC 6538p） and Micrococcus luteus（IFC 12708）,and Gram-negative bacteria viz. Proteus vulgaris（ATCC 3851）.Salmonella typhimurium（ATCC 14028） and Escherichia coli（ATCC 25922）.Among the screened compounds,5d,5e,5f,5g,and 5j exhibited potent inhibitory activity compared to standard drug,and emerged as potential molecules for further development.

Synthesis and Crystal Structure of 2-Ethoxy-3-n-butyl-benzofuro [2,3-d]pyrimidin-4(3H)-one

The crystal structure of the new title compound 2-ethoxy-3-n-butyl- benzofuro[2,3d]pyrimidin-4（3H）-one （C16H18N2O3, Mr = 286.32） has been prepared and determined by singlecrystal X-ray diffraction. The crystal is of monoclinic, space group P21/c with a = 13.7167（14）, b = 13.113（1）, c = 8.378（1） A, β = 98.992（2）^o, V = 1488.4（3） A^3, Z = 4, Dc = 1.278, F（000） = 608, μ = 0.089 mm^-1, MoKa radiation （2 = 0.71073）, R = 0.0498, wR = 0.1238 for 2336 observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals that all ring atoms in the benzo[4, 5]furo [2,3-d] pyrimi- dinone moieties are almost coplanar.

An efficient synthesis of 2,2-bis(1H-indol-3-yl)-2H-acenaphthen-1-one catalyzed by recyclable solid superacid SO_4^(2-)/TiO_2 under grinding condition

An efficient synthesis of symmetrical 2,2-bis（1H-indol-3-yl）-2H-acenaphthen-1-one is achieved via a reaction of acenaphthe-nequinone and indoles catalyzed by solid superacid SO4^2-/TiO2 under solvent-free conditions at room temperature by grinding, which provides an efficient route to the synthesis of symmetrical 2,2-bis（1H-indol-3-yl）-2H-acenaphthen-1-one.This procedure offers several advantages including solvent-free conditions,excellent yields of products,simple work-up as well as reuse of catalysts which makes it a useful and attractive protocol for the synthesis of these compounds.

Extraction of palladium(Ⅱ) from hydrochloride solutions with 2-n-octyl-4-isothiazolin-3-one as novel extractant

Solvent extraction of palladium （Ⅱ） from hydrochloric acid solution with 2-n-octyl-4-isothiazolin-3-one （OIT）/cyclohexane was studied. Effects of different parameters on extraction efficiency were evaluated. 99.96 % and 98.26 % palladium （Ⅱ） could be effectively extracted with 0.018 mol·L^-1 OIT/cyclohexane of 0.1 and 4.0 mol·L^-1 HCl medium, respectively. Nonpolar solvent and low acidity could improve the extracting efficiency, and successfully strip palladium （Ⅱ） from the loaded organic phase was achieved with 0.5 mol·L^-1 （NH2）2CS solution. It was proposed that the extraction of Pd com-plexes from HCl medium proceeded through the ion-association mechanism by slope method, NMR and FF-IR spectra.

Synthesis, Crystal Structure and Fungicidal Activity of (Z)-3,3-Dimethyl-1-(1H-1,2,4-triazol-1-yl)butan-2-one O-2-Chlorobenzyl Oxime Nitrate

The title compound has been synthesized by the reaction of 3,3-dimethyl-1-（1H-1,2,4-triazol-1-yl）butan-2-one oxime with 2-chlorobenzyl chloride, and then treated with 65～68% HNO3. Its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/c with a = 14.5481（8）, b = 9.3351（5）, c = 13.1911（7） , β = 98.9450（10）°, Z = 4, V = 1769.67（17） 3, Mr = 369.81, Dc = 1.388 g/cm3, S = 1.06, μ = 0.247 mm-1, F（000） = 776, the final R = 0.0352 and wR = 0.0960 for 3069 observed reflections （I 2σ（I））. X-ray crystal structure presents the intramolecular N–H…O hydrogen bond. The packing is nearly parallel without π-π stacking interactions between two adjacent phenyl rings and stabilized by Van der Waals force. The preliminary bioassay shows that the title compound possesses fungicidal activity against Gibberella zeae at the dosage of 25 mg/L.

Synthesis and Crystal Structure of Trans-4-[(5-(2,4-Dichlorophenoxy)-3-methyl-1-phenyl-1H-pyrazol-4-yl)methyleneamino]-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one

The title compound trans-4-[（5-（2,4-dichlorophenoxy）-3-methyl- 1-phenyl-1H-pyrazol-4-yl）methyleneamino]- 1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one 3 （C28H23Cl2N5O2, Mr = 532.41） has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P1- with a = 8.9438（4）, b = 11.6065（5）, c = 14.2215（6）A, α = 112.566（1）, β = 92.324（2）, γ = 102.91（1）°, V= 1315.65（10） A^3, Z = 2, Dc = 1.344 g/cm^3,μ（MoKa） = 0.282 mm^-1, λ = 0.71073 A, F（000） = 552, the final R = 0.0587 and wR = 0.1578 for 5071 observed reflections （I 〉 2σ（I））. X-ray analysis reveals that the product is a thermodynamically stable trans isomer. Intra- and intermolecular C（ 12）-H（12）…O（1） and C（28）-H（28）...O（1）# 1 hydrogen bonds were observed in the title compound.

1,5-Dimethy-4-[(3-nitro-benzylidene)-amino]-2-pheyl-1,2-dihydro-pyrazol-3-one

The title compound C18H16N4O3 （Mr = 336.35） has been synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. The Schiff base compound is a derivative of 4-aminoantipyrine. As expected, the molecular structure adopts a trans configuration about the central C=N double bond. It crystallizes in orthorhombic, space group P2dc with a = 7.632（1）, b = 7.816（1）, c = 28.082（5） A,β = 96.18（1）°, V= 1665.48（51） A^3, Z= 4, Dc = 1.341 g/cm^3, F（000） = 704,μ = 0.094 mm^-1, the final R = 0.0448 and wR = 0.1058. Of the total 3748 collections, 3105 were unique. In the molecule there exist two different planes of pyrazoline and C（11）-C（16） phenyl ring, which are approximately coplanar （r.m.s. de deviation from the combined mean plane is 0.03 A） with the dihedral angle between them of 9.8%.

Synthesis of some new bis-3,4-dihydropyrimidin-2(1H)-ones by using silica-supported tin chloride and titanium tetrachloride

Silica-supported tin chloride and titanium tetrachloride were prepared by the reaction of tin chloride and titanium tetrachloride with activated silica gel in refluxing toluene.These solid acids have been employed as the catalysts for the synthesis of bisdihydropyrimidin -2(1H)-ones from aromatic dialdehydes,1,3-dicarbonyl compounds and urea at 90℃under solvent-free conditions.

Efficient synthesis of 5,6-dihydrothieno[3′,2′:4,5]-thieno[2,3-d]pyrimidin-4(3H)-ones via an iminophosphorane

5,6-Dihydrothieno[3＇,2＇：4,5]thieno[2,3-d]pyrimidin-4（3H）-ones 6 were synthesized in yields of 71-87% by a consecutive method, which includes aza-Wittig reaction of iminophosphorane 3 with aromatic isocynate to give carbodiimide 4 and subsequent reaction of 4 with various amines, phenols or alcohols in the presence of catalytic amount of sodium ethoxide or solid potassium carbonate. 2009 Ming Wu Ding. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Synthesis and Crystal Structure of 2-(4’-Methylphenoxy)-5,8,9-trimethyl-3-phenyl Thieno[3′,2′:5,6]pyrido[4,3-d]pyrimidin-4-(3H)-one Hydrochloride

The title compound 2-（4＇-methylphenoxy）-5,8,9-trimethyl-3-phenyl thieno[3＇,2＇：5,6] pyrido[4,3-d]pyrimidin-4（3H）-one hydrochloride （C26H23Cl4N3O2S, Mr = 583.33） has been determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c with a = 14.8442（ 11 ）, b = 11.5131 （8）, c = 17.2010（13） A, β = 113.7250（10）°, V = 2691.3（3） ,A^3, Z = 4, Dc = 1.440 g/cm^3, S = 1.094,μ = 0.547 mm^-1, F（000） = 1200, the final R = 0.0571 and wR = 0.1458. X-ray analysis reveals that the title compound combines with a molecule of dichloromethane by an intramolecular hydrogen bond. The thienopyridine ring is almost coplanar, and the dihedral angle between the thiophene plane and the pyridine plane is 0.6°.

Synthesis and Crystal Structure of 1-(4-Fluorophenyl)-2-hexylthiobenzo[4,5]-furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5(1H)-one

The crystal structure of the title compound 1-（4-fluorophenyl） -2-hexylthio-benzo [4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5（1H） -one（C23H21FN4O2S,Mr = 436.5） has been prepared and determined by single-crystal X-ray diffraction. The crystal is of monoclinic,space group P21/n with a = 13.9854（3） ,b = 17.2678（4） ,c = 18.1828（5）A,β = 99.364（2） °,V = 4332.58（18） A^3,Z = 4,Dc = 1.338,F（000） =1824,μ = 0.185 mm^-1,MoKa radiation（λ = 0.71073） ,R = 0.0538 and wR = 0.1162 for 4728 observed reflections with I 〉 2σ（I） . X-ray diffraction analysis reveals the fused rings of benzo[4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a] pyrimidin-5（1H） -one system are nearly coplanar. The crystal packing is mainly stabilized by weak intermolecular C-H···O hydrogen bond and π-π interactions.

Enzymatic Synthesis and Characterization of Novel Polycarbonates Derived from 5-Allyloxy-1, 3-dioxan-2-one and 5, 5-Dimethvl-1.3-dioxan-2-one

Novel polycarbonates from 5-allyloxy-1, 3-dioxan-2-one （ATMC） with 5, 5-dimethyl- 1, 3-dioxan-2-one （DTC） were successfully synthesized for the first time using immobilized porcine pancreas lipase （IPPL） as catalyst. The resulting copolymers were characterized by IR, ^1H NMR, ^13C NMR and GPC. The molecular weight （Mn） of the copolymer with molar feed ratio of 10：90 （ATMC：DTC） was 9300 and the polydispersity was 1.31, while the Mn increased to 14300 and polydispersity of 1.25 with the feed ratio of 50：50. Moreover, the composition of the copolymers agreed well with the monomer feed.

Localization of a defensive volatile 4-hydroxy-4-methylpentan-2-one in the capitate glandular trichomes of Oenothera glazioviana

Glandular trichomes of plants produce a wide variety of secondary metabolites which are considered as major defensive chemicals. The capitate glandular trichomes of Oenothera glazioviana(Onagraceae) were collected with laser microdissection and analyzed by gas chromatography-mass spectrometry. The volatile compound 4-hydroxy-4-methylpentan-2-one(1) was identified. We found that compound 1 displays antimicrobial, insecticidal, and phytotoxic activities. These results suggest that compound 1 might function as a defensive compound in the capitate glandular trichomes of O. glazioviana against pathogens, insect herbivores, and presumably competitive plants as well.

Theoretical Study on the Structure and Vibrational Spectra for 4-methyl-3-penten-2-one

Density functional theory BLYP (using Becke's and Lee-Yang-Parr's correlation functionals), nb initio Hartree-Fock (HF) and hybrid DFT/HF B3LYP calculations were carried out to study the structure and vibrational spectra of 4-methyl-3-penten-2-one. The BLYP/6-31G* and scaled HF/6-31G* frequencies correspond well with each other and with available experimental assignment of the functional vibrational modes.