Synthesis and Fungicidal Activities of 2-Alkylthio-5- （3, 4, 5-tribenzyloxyphenyl）-1, 3, 4-oxadiazoles

Abstract： Ten novel 2-alkylthio-5-（3, 4, 5-tribenzyloxyphenyl）-1, 3, 4-oxadiazole derivatives （5a-j） were synthesized from methyl 3, 4, 5-trihydroxybenzoate by ethedfication, hydrazidation, cyclization and thioetherification reactions. The structures of 5a-j were confirmed by 1HNMR, MS spectra and elemental analysis. The results indicated that most of the compounds 5 exhibited good fungicidal activities. The activity of 5h is higher than 90% against Fusarium oxysporum and Botrytis cinereapers in 50 mg/L.     

Synthesis and Structure of Large Single Crystal of TPAF-AlPO_4-5 Molecular Sieve

A large single crystal of TPAF-AlPO4-5 molecular sieve was synthesized by hydrothermal crystallization in the presence of ammonium fluoride. Starting material composition was · 1 P2O5 · 1 Al2O3 · 2. 2 TPAOH · 1. 7 NH4F ·318 H2O. The crystal size has a hexagonal prism with 80μm across and 500μm length.The structure of tetrapropylarnmonium fluoride - aluminium phosphate type-5 was investigated with X-ray diffraction. The unit cell composition is 12AlPO4 · TPAF, space group P6cc (a= 13. 740(5), c= 8. 474(4) A ). Average bond distances are: P-O 1. 564A and Al-O 1. 640A ,which may be due to the partial disorder of the arrangement of P, Al in the framework. The angles of O-T-O and T-O-T (T?P, Al) are 102-116° and 148-176°, respectively. Residue electron density was not well enough defined to give a precise position for tetrapropylammonium fluoride (TPAF). The template agent, TPA cations, situate in the 12-ring channels and F- anions locate in double 4-rings near the 12-ring channels. Fixing atomic     

Synthesis and Antibacterial Activity of 8-Substituted Phenyl-1-pyridin-3-yl-5H-bis[1, 2, 4]triazolo[3, 4-b； 4＇, 3＇-d][1, 3, 4] thiadiazines

To find new structural leading compounds for the research of the multidrug resistant of antibacterial agents, five novel 8-substituted phenyl-l-pyridin-3-yl-5H-bis[1, 2, 4] triazolo[3, 4-b;4‘,3‘-d] thiadiazines were prepared from the corresponding intermediates of 3-(5-substituted phenyl[1,3,4]oxadiazol-2-ylmethylsulfanyl)-5-pyridin-3-yl-[1,2,4]triazol-4-ylamines via intramolecular cyclization and the antibacterial activity in vitro against Gram-postive (G^ ) and Gramnegatiye (G) bacteria was primarily evaluated.     

A Novel Fused Phosphorus Heterocycle: 4-(1'''',2'''',3'''',4-Tetrahydro-1, 3, 2-benzodiazaphosphorin-2''''-sulfide)-3, 4b, 4a-thiazphosphaphenanthridine Derivative

Organophosphorus compounds are ubiquitous in nature and they have broad applications in the fields of agriculture and medicine1-4. There has been a considerably growing interest in heterocyclic compounds due to their pharmaceutical importance and extensive application in organic synthesis, and the application of heterocycles is suggested to enhance the biological activity and/or offer other diverse properties5-7. In the previous work8, we have reported that 11-ethoxycarbonylmethyl-6-oxo-3, 4…     

A Selective Synthesis of 2-Alkylamino-5, 6, 7, 8-tetrahydrobenzothieno[2, 3-d]pyrimidin-4（3H）-ones

2-Alkylamino-5, 6, 7, 8-tetrahydrobenzothieno [2,3-d] pyrimidin-4(3H)-ones 7 were synthesized by a new selective synthetic method, which includes aza-Wittig reaction of iminophosphorane 4 with aromatic isocynate to give carbodiimide 5 and subsequent reaction of 5 with various aliphatic primary amine in the presence of EtO^-Na^ .     

Toward Total Synthesis of Yohimbine and Reserpine Alkaloids;Part 1.An Improved Synthesis of cis-5,8-Dihydroxy-1,4,5,8,9,10-hexahydronaphthalene-1,8-lactone via Selective Reduction of the Conjugated Ketone with Zn(BH_4)_2

cis-5, 8-Dihydroxy-1, 4, 5, 8, 9, 10-hexahydronaphthalene-1, 8-lactone 7 is the key intermediate to build E ring 2 possessing five chiral centers in total synthesis of (-)-reserpine 11, 2. In 1958, Woodward firstly reported an artful route to the synthesis of (-)-reserpine from the acid 4. One major drawback of this promising approach is the low yield obtained in the synthesis of the required lactone 7. Herein, we described an efficient and improved method for the synthesis of 7 as shown …     

Design and Synthesis of 3, 4-Dihydropyrrolo[2, 1-c][1, 4]oxazin-l-one and its 7-Acyl Derivatives

Starting from 1H-pyrrole, unreported 3, 4-dihydropyrrolo[2, 1-c][1, 4]oxazin-1-one 4, 7-(4-chlorobenzoyl)-3, 4-dihydropyrrolo[2, 1-c][1, 4]oxazin-1-one 5 and 7-benzoyl-3, 4-dihydro-pyrrolo [2, 1-c][1, 4]oxazin-1-one 9 were designed and synthesized. They may have antipyretic and analgesic activities.     

Facile Synthesis of Enantiomerically Pure 1-（5-Bromo-2-chlorophenyl）-1-（4-ethoxyphenyl）ethane

A facile 7-step procedure for the synthesis of enantiomerically pure 1-（5-bromo-2-chlorophenyl）-1-（4-ethoxyphenyl）ethanes[（R）-2 and（S）-2] that started from （5-bromo-2-chlorophenyl）（4-ethoxyphenyl）methanone 3 was developed.The key step was the resolution of 2-（5-bromo-2-chlorophenyl）-2-（4-ethoxyphenyl）acetic acid 6 by crystallizations of its L-and D-menthyl esters 7 and 8 from petroleum ether to give optically pure enantiomers 9 and 10,respectively.The absolute configurations of the products were unambiguously determined by single-crystal X-ray diffractions of four key intermediates,9,10,13 and 14.This procedure is characterized by inexpensiveness,scalability and ability to produce two individual enantiomers of a diarylethane with unambiguously determined absolute configurations and high enantiomeric purities.     

Synthesis and Antitumor Activity of Tanshinone Analogues

8, 8-Dimethyl-5, 6, 7,8-tetrahydrophenanthrene-3, 4-dione (3) and 8, 8-dimethyl-2- ( 1-hydroxy ethyl) -5,6, 7, 8-tetrahydrophenanthrene-3,4-dione (4), two analogues of the antitumor active tanshinone, were synthesized from anisole. The synthesized compounds 3 and 4 were shown to be highly active against leukemia P-388 cell fine as assayed by in vitro MTT method.     

The First Total Synthesis of Saurufuran B

First total synthesis of saurufuran B 1, a furanoditerpene, from （E, E）-farnesol 2 and citraconic anhydride 3 through thirteen steps is described. Our work involves two key steps： （1） High regioselective alkylation of 2-（tert-butyldimethylsiloxy）-4-methylfuran 6 with aUylic iodides 5 in the presence of silver wifluoroacetate and （2） Conversion of substituted 7-1actone 7 into furan derivative 8.     

Facile Synthesis of 1, 2-Diazepine Derivatives under Microwave Irradiation

An efficient and convenient synthesis of 3, 5, 7-triaryl-4H-1, 2-diazepine from 2, 4,6-triarylpyrylium salts and hydrazine in water under microwave irradiation is reported. The same reaction can be conducted using 2, 4, 6-triarylthiopyrylium salts and hydrazine.     

Design and Synthesis of 3,4-Dihydropyrrolo[2, 1-c][1, 4]oxazin-1-oneand its 7-Acyl Derivatives

Starting from 1H-pyrrole, unreported 3, 4-dihydropyrrolo[2, 1-c][l, 4]oxazin-1-one 4, 7-(4-chlorobenzoyl)-3, 4-dihydropyrrolo[2, 1-c][1, 4]oxazin-1-one 5 and 7-benzoyl-3, 4-dihydro-pyrrolo [2, 1-c][1, 4]oxazin-1-one 9 were designed and synthesized. They may have antipyretic and analgesic activities.     

Synthesis,Photochromism and Crystal Structure of 1-（2-Cyano-l,5-dimethyl-4-pyrryl）-2- [2-methyl-5- （3-pyridyl）-3-thienyl]perfluorocyclopentene

A new family of photochromic diarylethene compounds, 1-（2-cyano-l,5-dimethyl- 4-pyrryl）-2-[2-methyl-5-（3-pyridyl）-3-thienyl]perfluorocyclopentene （lo） having an unsymmetrical pyrryl and thienyl substituted hexafluorocyclopentene unit, was synthesized and its structure was determined by X-ray analysis. The crystal belongs to triclinic system, space group PI with a = 8.897（7）, b = 10.139（8）, c = 12.361（9） A, α = 85.222（7）, ρ = 75.439（7）, γ = 78.736（8）°, Z = 2, V= 1057.8（14） A3, D,.= 1.468 mg/m3, p = 0.220 mm-1, F（000） = 476, the final R = 0.0608 and wR = 0.1754 for 3199 observed reflections （1 〉20（/））. Interestingly, compound 1 exhibits good photochromic properties with alternate irradiation of UV light and visible light （〉 510 nm） to form two photoisomers in hexane solution and crystal phase.     

Synthesis of 1-[6-Fluoro-(2S)-3H,4H-dihydro-2H-2-chromenyl]-(1R)-1,2- ethanediol and 1-[6-Fluoro-(2R)-3H,4H-dihydro-2H-2-chromenyl]- (1R)-1,2-ethanediol

Benzopyran compounds possess diverse pharmacological properties such as β-blockade, anticonvulsant and antimicrobial.[1,2] Our interest has been focused on the synthesis of 1-[6-Fluoro-2S]-3H,4H-dihydro-2H-2-chromenyl]-(1R)-1,2-ethanediol (6) and 1-[6-fluoro-(2R)-3H,4H-dihydro-2H-2-chromenyl]-(1R)-1,2-ethanediol (7) which are particularly convenient precursor to (S,R,R,R)-NE (8). 8 containing four asymmetrical carbon atoms was reported to be the most active isomer.[3] Chandrasekhar[4] has reported on the synthesis of 8. The key step to synthesize this compound is to obtain the chiral chromanone 6 and 7. 6 was accomplished in 8 steps by the Clasien rearrangement and a one-pot Sharpless asymmetric epoxidation, but the compound 7 was accomplished in 10 steps. Johannes[5] used Zr-catalytic kinetic resolution of allylic ethers and Mo-catalyzed chromene formation to synthesize 8 in 14 steps. However both of the methods request many synthetic steps and expensive reagents.     

Synthesis and Characterization of Ti-ZSM-5 in a Non-alkaline Medium in the Presence of Fluoride Ions

Ti-ZSM-5 was synthesized by hydro thermal crystallization in the presence of fluoride via using a non-alkaline medium. pH values were 5~7. SEM showed perfect Ti-ZSM-5 crystals and a large single crystal growing from the favourable medium. Substitution of titanium for silicon in the ZSM-5 framework led to a decrease of crystal size and of the length/width ratio. Electron microprobe analysis indicated a homogeneous distribution of titanium in the ZSM-5 framework. The unit cell parameters of the Ti-ZSM-5 determined by XRD increased with an increase in titanium content in the framework. TiO4tetrahedron vibrations were found in the IR spectrum. Si(1Ti) peakwas seen in the 29Si MAS NMR spectrum at -1O1ppm(from TMS) and 13CMAS NMR analysis verified the effect of (C3H7)4N F- occluded in thechannels. XPS study on the precursors, calcined and H2O2 adsorbed Ti-ZSM-5 was performed and some interesting results were observed.     

Synthesis of 5-Deoxy-5-Acyloxyiminoavermectin B1 Derivatives

The avermectins1 are a unique collection of naturally occurring macrocyclic lactones with broad spectrum of anthelmintic and insecticidal activities. Their remarkable biological activity and complex molecular architecture stimulated significant interest in the scientific community. Much research has been carried out on these compounds. Many derivatives of avermectin have much more bioactivities and have been commercially utilized2-5. Here we describe the synthesis of 5-deoxy-5-acyloxyimi…     

The Synthesis of 2, 4, 6-Triisopropyl-1, 3, 5-trioxane Catalyzed by Ionic Liquids

The synthesis of 2, 4, 6-triisopropyl- 1, 3, 5-trioxane with high yield and desirable selectivity from solvent-free cyclotrimerization of isobutyraldehyde catalyzed by ionic liquids was reported in this work.     

First Total Synthesis of 4,5-Sccoeudesmane-type and Iphionane-type Compounds-Synthesis of 4,5-Dioxo-seco-γ-eudesmol and 5β,11-Dihydroxyiphionan-4-one

4, 5-Secoeudesmane-type and iphionane-type compounds are sesquiterpenes with newcarbon skeletons found in natrual sources in recent years.1-6 The co-occurence of 4, 5secoeudesmanes, iphionanes and eudesmanes as natrual products suggests that 4, 5secoeudesmanes, iphionanes most likely are generated biogenetically tyom eudesmanes,and iphionanes are formed biogenetically by aldol reaction of 4, 5dioxosecoeudesmanes1,4,6,7 The study on the synthesis of this two kind of newsesquiterpenes has not be…     

Total Synthesis of Two 4, 5-Dioxo-seco-eudesmane Sesquiterpenes

A facile synthetic route to two seco-eudesmane, 4, 5-dioxo-10-epi-4, 5-seco-γ-eudesmane (1) and 4, 5-dioxo-10-epi-4, 5-seco-γ-eudesmol (2) from ( )-dihydrocarvone has been described. Avoiding expensive reagents, this highly economic method especially suits for the synthesis of 4, 5-seco-eudesman-type and ophianon-type sesquiterpenes with a double bond at position 11 and 12.     

Stereoselective Synthesis of (±) Neocnidilide

The lactone neocnidilide 8 occur in the roots of Cnidilide officinale1 which is shown to inhibit the growth and toxin production of mycotoxin-producing fungi2. Although The synthesis of lactones 7, which is stereoisomer of cnidilide, and 8 had been reported by others3, 4, we would like to report the highly stereoselective synthesis of its racemic isomer 8 as shown in Scheme 1. Scheme 1 COOHHOOCbcOOHH1234d5eOHOHHH 6fOOHHH 7g8COOHOHa12345673a7aOHHOH1235673 a7a1234561'1'2'…