- Synthesis of 3a,4-dihydro-8-substituted-3H-isoxazolo [c- 4,3] thiapyrano [5,6-3,2] quinolines
-
Condensation of 2-chloro-3-formylquinoline 1a-c with allylthiol 2 afforded 2-allysulfanyl-3-formylquinolines 3a-c. Oximation followed by oxidation of 3a-c with NaOCl or chloramine-T, in cold or mercuric acetate resulted in the formation of respective nitrile oxides, which underwent insitu intramolecular 1,3-dipolar cycloaddition reaction and afforded the title compounds 5a-c in high yield.
- Prabhuswamy,Ambekar, Sarvottam Y.
-
-
Read Online
- Preparation method of thiocarboxylate silane coupling agent
-
The invention provides a preparation method of a thiocarboxylate silane coupling agent. The preparation method comprises steps as follows: allyl mercaptan is prepared from allyl haloalkane and hydrosulfide under the condition of a phase transfer catalyst and subjected to a reaction with acyl chloride in the presence or absence of a solvent, allyl thiocarboxylate is obtained, and low-boiling-point substances are removed through evaporation for purification of a product; purified allyl thiocarboxylate and trialkoxysilane are subjected to an addition reaction in presence of a transition metal catalyst, and after decoloration and distillation, a thiocarboxylate silane product is obtained. The preparation method has the advantages as follows: use of mercapto silane with pungent smell is avoided, and harm to the environment is reduced; the reaction of acyl chloride and sulfide or hydrosulfide under the aqueous phase condition is avoided, so that side reactions are reduced, and impurities are reduced; hydrolysis rate of the product is lower, yield is increased, and product purity is high.
- -
-
Paragraph 0023-0025; 0030-0032; 0037-0039; 0044-0046
(2018/03/24)
-
- OLEFIN METATHESIS REACTIONS OF AMINO ACIDS, PEPTIDES AND PROTEINS CONTAINING ALLYL SULFIDE GROUPS
-
A method for the modification of an amino acid, protein or peptide is disclosed. The method comprises reacting a carbon-carbon double bond-containing compound with an amino acid, a protein or a peptide containing an allyl sulfide group in the presence of a catalyst which promotes olefin metathesis, to form a modified amino acid, protein or peptide. Preferred carbon-carbon double bond-containing compounds include carbohydrates.
- -
-
Page/Page column 9
(2012/07/27)
-
- METHOD FOR PRODUCING ALKENYL MERCAPTAN
-
The present invention relates to a process for producing an alkenyl mercaptan (2), comprising reacting an alkenyl halide (1) with an alkali hydrosulfide, wherein the reaction is carried out in the presence of a disulfide (3) in an amount of 0.5 part by weight or more based on 100 parts by weight of the total amount of the alkenyl halide (1) and the alkenyl mercaptan (2).
- -
-
Page/Page column 3-4
(2011/10/02)
-
- CHLOROTHIOFORMATE MANUFACTURING METHOD
-
The present invention relates to a process for producing chlorothioformate comprising reacting an alkenyl mercaptan with phosgene in a reactor in the presence of a carboxylic acid amide in an organic solvent, characterized in that the carboxylic acid amide is preliminary charged to the reactor in an amount of 10 to 50% by weight based on the whole amount of the carboxylic acid amide, and subsequently, the compound of the formula (I), phosgene and the remaining carboxylic acid amide are charged to the reactor.
- -
-
Page/Page column 3
(2011/10/19)
-
- Reaction mechanisms of allicin and allyl-mixed disulfides with proteins and small thiol molecules
-
Allylsulfides from garlic are chemopreventive agents. Entering cells they are expected to initially interact with glutathione. Accordingly, reaction mechanisms of the product, S-allylthio-glutathione, with model proteins and thiols were analyzed in cell f
- Miron, Talia,Listowsky, Irving,Wilchek, Meir
-
body text
p. 1912 - 1918
(2010/07/04)
-
- Allyl sulfides are privileged substrates in aqueous cross-metathesis: Application to site-selective protein modification
-
Allyl sulfides undergo efficient cross-metathesis in aqueous media with Hoveyda-Grubbs second generation catalyst 1. The high reactivity of allyl sulfides in cross-metathesis was exploited in the first examples of cross-metathesis on a protein surface. S-Allylcysteine was incorporated chemically into the protein, providing the requisite allyl sulfide handle. Preliminary efforts to genetically incorporate S-allylcysteine into proteins are also reported. Copyright
- Lin, Yuya A.,Chalker, Justin M.,Floyd, Nicola,Bernardes, Goncalo J. L.,Davis, Benjamin G.
-
supporting information; experimental part
p. 9642 - 9643
(2009/02/04)
-
- Synthesis of conformationally restricted nicotine analogues by intramolecular [3+2] cycloaddition
-
We describe the synthesis of a series of conformationally constrained nicotine analogues 2-5 from appropriate pyridine-containing enals, featuring an intramolecular azomethine ylide-alkene [3+2] cycloaddition. The objective of the current project is to develop new selective nAChRs-targeting ligands. Of the nicotine analogues that we have studied, the conformation-restricting ring B unit can be either a five-membered carbocycle, or a six-membered carbocycle or heterocycle. The present work constitutes a general method for rapid assembly of other related tricyclic nicotine analogues.
- Yang, Xiaobao,Luo, Shengjun,Fang, Fang,Liu, Peng,Lu, Yong,He, Mingyuan,Zhai, Hongbin
-
p. 2240 - 2246
(2007/10/03)
-
- Kinetics and mechanism of the nucleophilic substitution of tellurium(II) dialkanethiolates, Te(SR1)2 with thiols, HSR2
-
The equilibrium reaction between tellurium(II) dithiolates and thiols, Te(SR1)2 + 2 HSR2 ? Te(SR 2)2 + 2 HSR1 was studied by means of 1H- and 125Te NMR spectroscopy and ab initio quantum chemical methods. It was found that the reaction is catalyzed by Bronsted acids and bases, the catalytic activity corresponding to the strength of the respective acid or base. Investigation of the initial step of the reaction, Te(SR1)2 + HSR2 ? Te(SR 1)(SR2) + HSR1, showed it to proceed according to first order kinetics for Te(SR1)2, HSR2 and for the catalyst. Ab initio geometry optimizations and frequency calculations suggest [Te(SR1)(HSR1)(HSR2)]+ and [Te(SR1)2(SR2)]- to be stable intermediates and not transition states in the acid and base catalyzed reactions, respectively. The reaction hence proceeds via an additional elimination rather than an SN2 mechanism. The catalytic activity displayed by acids and bases can be applied to reduce the temperature in synthesis of thermally labile tellurium(II) dithiolates. Copyright Taylor & Francis Inc.
- Fleischer, Holger
-
p. 815 - 825
(2007/10/03)
-
- Absolute Rate Constants for Reactions of Tributylstannyl Radicals with Bromoalkanes, Episulfides, and α-Halomethyl-Episulfides, -Cyclopropanes, and -Oxiranes: New Rate Expressions for Sulfur and Bromine Atom Abstraction
-
Arrhenius rate expressions were determined for the abstraction of bromine atom from 2-phenethyl bromide by tri-n-butylstannyl radical (Bu 3Sn.) in benzene using transient absorption spectroscopy, (log(kabs,Br/M-1 s-1) = (9.21 ± 0.20) - (2.23 ± 0.28)/θ, θ = 2.3RT kcal/mol, errors are 2σ) and for the abstraction of sulfur atom from propylene sulfide to form propylene, (log(ks/M-1 s-1) = (8.75 ± 0.91) - (2.35 ±1.33)/θ). Rate constants for reactions of organic bromides, RBr, with Bu3Sn. were found to vary as R = benzyl (15.6) > thiiranylmethyl (6.2) > oxiranylmethyl (3.1) > cyclopropylmethyl (1.3) > 2-phenethyl (1.0), with kabs,Br = 6.8 × 10 7 M-1 s-1 at 353 K for 2-phenethyl bromide. Bromine abstraction from α-bromomethylthiirane is about 7-fold faster than sulfur atom abstraction and is comparable to the reactivity of a secondary alkyl bromide. The potential surface for the vinylthiomethyl → allylthiyl radical rearrangement at UB3LYP/6-31G(d) and UB3LYP/6-311+G-(2d,2p) levels of theory suggests that the thiiranylmethyl radical is produced about 9 kcal/mol above the allylthiyl radical on the rearrangement surface, consistent with the observed enhancement of the Br atom abstraction from the thiirane and with synchronous C-S bond scission of the thiirane ring. The selectivities reported in this work for S vs Cl and Br abstraction provide applications for radical-based synthesis and new competition basis rate expressions for trialkylstannyl radicals.
- Franz, James A.,Shaw, Wendy J.,Lamb, Claude N.,Autrey, Tom,Kolwaite, Douglas S.,Camaioni, Donald M.,Alnajjar, Mikhail S.
-
p. 1020 - 1027
(2007/10/03)
-
- 6-O-acyl ketolide antibacterials
-
6-O-Acyl ketolide antibacterials of the formula: wherein R1, R2, R3, R4, W, X, X′, Y, and Y′ are as described herein and in which the substituents have the meaning indicated in the description. These compounds are useful as antibacterial agents.
- -
-
-
- A novel, practical and highly chemoselective methodology for reduction of disulphides to thiols
-
A novel, simple and efficient method for the reduction of disulfides to thiols using In/NH4Cl is described.
- Vidya Sagar Reddy,Venkat Rao,Iyengar
-
p. 859 - 862
(2007/10/03)
-
- A general and mild synthesis of thioesters and thiols from halides
-
The conversion of a wide variety of halides to thioesters by reaction with potassium thiocetate under mild conditions is described, and the generality of the method is demonstrated.
- Zheng, Tu-Cai,Burkart, Maureen,Richardson, David E.
-
p. 603 - 606
(2007/10/03)
-
- Flash vacuum thermolysis - Synthesis and characterization of unstabilized cycloalkenethiones
-
The flash vacuum thermolysis (FVT) of cydoalkenyl allyl (or propargyl) sulfides 8, 9, 12, and 13 led, as the main thermal pathway, to the conjugated cycloalkenethiones 1, 3, and 5, resulting from a retro-ene reaction. These reactive thioketones, thus obtained in ca. 70% yield, have been characterized in the gas phase by mass spectrometry, and at low temperature by IR, UV/Vis and NMR spectroscopy. The polymerization of 1, 3, and 5 upon warming is generally more rapid than the other attempted reactions and only the [2 + 3] dipolar cycloaddition with diazomethane led in low yield, besides polymeric materials, to isomeric 1,3-dithiolanes 20 from cyclopentenethione 1. The obtention of the nonconjugated cycloalkenethiones 2 and 4, expected in the FVT of sulfides 10 and 11, has been confirmed only by UV/Vis spectroscopy at -196 °C, due to their rapid enethiolization. In the case of the large-ring sulfide 14, the (E) geometry of the double bond favoured the competitive retro-ene reaction yielding cyclododecene and propynethial; on the other hand, the FVT of the tricyclic gem-dithiol 15, a possible precursor of cyclobutenethione (7), led to vinyl thioketene (18), obtained by thermal ring opening of 7.
- Briard, Emmanuelle,Levillain, Jocelyne,Ripoll, Jean-Louis,Dat, Yves,Marcual, Albert,Lange, Catherine
-
p. 869 - 874
(2007/10/03)
-
- Benzothiazole derivatives and methods of use
-
The present invention relates to a novel benzothiazole derivative of the following general formula (I) or its (E) , (Z)isomer, and processes for preparation thereof, STR1 in which R1, R2 and R3 independently of one another represent hydrogen, halogen, straight and branched (C1 -C8)alkyl, (C1 -C8)halogenoalkyl or (C1 -C8)alkoxy, X represents N or CH, Y represents a group -OR4, SR5 or STR2 R4, R5, R6 and R7 independently of one another represent hydrogen, straight and branched (C1 -C16)alkyl, (C3 -C8)alkenyl, (C3 -C8)alkynyl, (C3 -C8)cycloalkyl, alkyl substituted with (C1 -C6)alkoxy or (C1 -C6)halogenoalkyl, or represent a substituted phenyl, phenylacyl or benzyl group wherein the possible substituent on the phenyl, phenylacyl or benzyl group includes halogen, straight and branched (C1 -C8)alkyl, (C1 -C8)alkoxy, (C3 -C8)alkenyl, (C3 -C8)alkynyl, phenoxy, nitro, cyano and a five- or six-membered heterocyclic group containing one to four nitrogen atoms. The compound of formula (I) is useful for combating phythopathogenic organisms and fungi present on animal.
- -
-
-
- Novel benzothiazole derivatives and processes for preparing the same
-
The present invention relates to a novel benzothiazole derivative of the following general formula (I) or its (E), (Z)-isomer, and processes for preparation thereof, in which R1, R2 and R3independently of one another represent hydrogen, halogen, straight and branched (C1-C8)alkyl, (C1-C8) halogenoalkyl or (C1-C8)alkoxy, Xrepresents N or CH, Yrepresents a group -OR4, -SR5 or R4, R5, R6 and R7independently of one another represent hydrogen, straight and branched (C1-C16)alkyl, (C3-C8)alkenyl, (C3-C8)alkynyl, (C3-C8)cycloalkyl, alkyl substituted with (C1-C6)alkoxy or (C1-C6)halogenoalkyl, or represent a substituted phenyl, phenylacyl or benzyl group wherein the possible substituent on the phenyl, phenylacyl or benzyl group includes halogen, straight and branched (C1-C8)alkyl, (C1-C8)alkoxy, (C3-C8)alkenyl, (C3-C8)alkynyl, phenoxy, nitro, cyano and a five- or six-membered heterocyclic group containing one to four nitrogen atoms. The compound of formula (I) is useful for combating phythopathogenic organisms and fungi present on animal.
- -
-
-
- Gas-phase SN2 and E2 reactions of alkyl halides
-
Rate coefficients have been measured for the gas-phase reactions of methyl, ethyl, n-propyl, isopropyl, tert-butyl, and neopentyl chlorides and bromides with the following set of nucleophiles, listed in order of decreasing basicity: HO-, CH3O-, F-, HO- (H2O), CF3CH2O-, H2NS-, C2F5CH2O-, HS-, and Cl-. For methyl chloride the reaction efficiency first falls significantly below unity with HO- (H2O) as the nucleophile and for methyl bromide with HS- as the nucleophile; in both cases the overall reaction exothermicity is about 30 kcal mol-1. Earlier conclusions that these halides react slowly with stronger bases are shown to be in error. In the region where the rates are slow oxygen anions react with the alkyl chlorides and bromides by elimination while sulfur anions of the same basicity react by substitution. This difference is due to a slowing down of elimination with the sulfur bases; sulfur anions show no increased nucleophilicity as compared to oxy anions of the same basicity. Rate coefficients have also been measured for reaction of methyl fluoride with HO- and CH3O- and ethylene oxide with HO-, CH3O-, and F-. All of these rates are slow but measurable; combining the results of these experiments with those of the alkyl chlorides and bromides suggests that the gas-phase barrier to the symmetrical SN2 reaction of F- with methyl fluoride is lower than previous estimates. We have also measured rates for reaction of allyl chloride with F-, H2NS-, and HS-, chloromethyl ether with H2NS- and HS-, chloroacetonitrile with F-, H2NS-, HS-, and 37Cl-, bromoacetonitrile with Cl- and 81Br-, and α-chloroacetone with H2NS-, HS-, and 37Cl-. Our results also imply that the gas-phase SN2 barrier for Br- reacting with methyl bromide is nearly equal to the ion-dipole attraction energy of the reactants, in agreement with previous estimates.
- DePuy, Charles H.,Gronert, Scott,Mullin, Amy,Bierbaum, Veronica M.
-
p. 8650 - 8655
(2007/10/02)
-
- Antimicrobial composition and method containing N-(3,5-dihalophenyl)-imide compounds
-
Novel N-(3,5-dihalophenyl)imide compounds, which exhibit a strong antimicrobial activity against microorganisms including phytopathogenic fungi, parasites of industrial products and pathogenic microorganisms, represented by the formula, STR1 wherein X and X' each represent halogens and A represents a substituted ethylene such as chloroethylene, C1 - C4 alkylthioethylene, C1 - C2 alkyl-ethylene or 1,2-di-C1 - C2 -alkyl-ethylene, a cyclopropylene such as 1,3-dimethylcyclopropylene, trimethylene, a cyclohexylene-1,2-, cyclohexenylene-1,2-, cyclohexadienylene-1,2- or o-phenylene. The N-(3,5-dihalophenyl)imide compounds can be obtained by any of methods which produce imide compounds or reaction of an N-(3,5-dihalophenyl)maleimide compound with a mercaptan, a hydrogen halide, phosphorus chloride or thionylchloride.
- -
-
-
