107-05-1

Radical-promoted tributyltin hydride reduction of 3,3-dichloropropene, (Z)-1,3-dichloropropene, or (E)-1,3-dichloropropene yields a mixture of the three possible regio-stereoisomeric monochloropropenes.The palladium-catalyzed reduction yields regiospecifically the two stereoisomeric 1-chloropropenes with a Z/E ratio which remains constant whatever the starting dichloropropene but which is not the thermodynamic ratio.The results are against a radical mechanism and strongly support a polar ?-allyl mechanism for the catalytic reactions.

The thermal decomposition reaction of 1,2-dichloropropane (1,2-DCP) was studied at temperatures from 663.2 to 703.2 K over the pressure range 0.04-10.0 Torr.The decomposition modes of 1,2-DCP were monitored via four reaction channels of unimolecular HCl eliminations and a negligible portion of a side radical chain reaction. 3-Chloropropene (3-CP), cis-1-chloropropene (cis-1-CP), trans-1-chloropropene (trans-1-CP), and 2-chloropropene (2-CP) were produced.Rate parameters for the thermal processes found in this study are k3(3-CP)/s-1=1013.61 +/- 0.30exp-1/RT>, kcis(cis-1-CP)/s-1=1012.90 +/- 0.70exp-1/RT>, ktrans(trans-1-CP)/s-1=1013.21 +/- 0.80exp-1/RT>, k2(2-CP)/s-1=1013.05 +/- 0.44exp-1/RT>, and ktot(total)/s-1=1013.70 +/- 0.50exp-1/RT>.The unimolecular thermal decomposition reactions of the four-channel 1,2-DCP system were carried out in the presence of a He bath gas to evaluate intermolecular-energy-transfer parameters.The average energies removed per collision from energized 1,2-DCP by bath gas are as follows: by the substrate, 1200 cm-1 for the stepladder model; by He, 250 cm-1 for the exponential model.The effects of active additives, CO2 and HCl, and the surface condition of the reaction vessel were also studied to ascertain the potential properties of the thermal decomposition reaction of 1,2-DCP.

Several examples of synthetically unique reaction controll effect by pulsed infrared laser multiphoton irradiation are reviewed.The uniqueness derives from the ability of the pulsed laser to rapidly vibrationally heat molecules coupled with an extremely short reaction time of approximately 10 μs for the processes discussed herein.Three systems are discussed: a bifunctional reactant with competing reaction channels, a reactant with consecutive reaction channels, and the free radical chlorination of cyclopropane.

The rate constant for the reaction Cl + C3H6 (k1) has been measured relative to that of Cl + C2H6 over the range 0.3-700 Torr in N2 at 298 K. UV irradiation was used to generate Cl atoms in mixtures of C3H6, C2H6, Cl2, and N2 in two different reactors using FTIR or GC analysis. The yields of the two major products, allyl chloride (3-C3H5Cl) and 1,2-dichloropropane were measured. k1 decreases by a factor of 5 between 700 and 1 Torr. Below 1 Torr, the rate constant becomes independent of pressure. The results indicate that k1 is a composite of three reaction channels, each having a different pressure dependence. Measurement of the yield of 1,2-dichloropropane, the final product formed from the addition of Cl to C3H6, at each pressure allows a determination of the rate constant (k1a) for the addition of Cl to C3H6. Assuming a typical center broadening factor (Fc = 0.6), the high- and low-pressure limiting constants are calculated to be k1a(∞) = (2.7 ± 0.4) × 10-10 cm3 molecule-1 s-1 and k1a(0) = (4.0 ± 0.4) × 10-28 cm6 molecule-2 s-1. The pressure dependence of the yield of 3-C3H5Cl indicates that the allyl radical is likely formed by both abstraction and addition-elimination channels. The rate constant of the abstraction reaction from the methyl radical in C3H6 is (2.3 ± 0.3) × 10-11 cm3 molecule-1 s-1. At pressures below 10 Torr, the rate constant for formation of the allyl radical increases by 50%, and this is ascribed to an addition-elimination process. Relative rate constant ratios were also measured for Cl atom reactions with allyl chloride (k6) and 1,2-dichloropropane (k7) relative to C3H6, C2H5Cl, or CH3Cl to correct the product yield experiments for secondary consumption. The observed values of k6/k1 are 0.75 for total pressures of 10-700 Torr, 0.44 at 1 Torr, and 0.33 at 0.4 Torr. On the basis of the relative rate measurements k7 = (3.9 ± 0.6) × 10-12 cm3 molecule-1 s-1 over the range 1-700 Torr.

The kinetics of the reactions of three unsaturated free radicals (vinyl, allyl, and propargyl) with molecular chlorine have been studied by using a tubular reactor coupled to a photoionization mass spectrometer.The radicals were homogeneously generated by the pulsed photolysis of precursor molecules at 193 nm.The subsequent decays of the radical concentrations were monitored in real-time experiments as a function of Cl2 concentration to obtain the rate constants of these Cl atom metathesis reactions.Rate constants were measured as a function of temperature to obtain Arrhenius parameters.The following rate constant expressions were obtained (units of the preexponential factor are cm3 molecule-1 s-1, and activation energies are in kJ mol-1; the temperature range covered in each study is also indicated): C2H3 + Cl2; C3H3 + Cl2 ; C3H5 + Cl2 .The factors governing the reactivity of polyatomic free radicals in these and other Cl atom transfer reactions with molecular chlorine are reviewed.

Dehydrochlorination of 1,2-dichloropropane was conducted with and without irradiation of KrF excimer laser (248 nm).It afforded four products, cis-1-, trans-1-, 2-, and 3-chloropropene.The reaction was remarkably accelerated with irradiation of laser especially at the low temperatures.

(Chemical Equation Presented) The decomposition of allyloxychlorocarbene in hydrocarbon solvents leads via homolysis to allyl and COCl radicals, which recombine to 3-butenoyl chloride or (after scission of ?COCl to CO and ?Cl) to all

Inclusion compounds of di-μ-chloro-bis(η-allyl)dipalladium and its analogues with cyclodextrins (CDs; α-CD, β-CD, and γ-CD) were prepared.One-to-one inclusion compounds were obtained in high yields by the treatment of β- and γ-cyclodextrin with di-μ-chlor

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Silphos [PCl3-n(SiO2)n] as a heterogeneous phosphine reagent is efficiently applied for the transformation of epoxides to β-bromoformates in the presence of bromine or N-bromosuccinimide in dimethyl formamide at 0 °C. The combination of Silphos and iodine was also found suitable for the room temperature preparation of alkenes. The use of Silphos provides the advantage of easy separation of the phosphine oxide by-product from the reaction mixture.

The ready decomposition of the vinyl-di-μ-methylene-dirhodium complex, >, to give C3 (propene or η3-allylic ligands) by linking of the vinyl and methylene ligands, prompts the proposal of a new mechanism for the polymerisation step in the Fischer-Tropsch reaction in which the polymer chain carriers are surface alkenyls rather than alkyls.

The invention belongs to the technical field of chemical synthesis of pesticides, and particularly relates to a method for preparing 2-chloro-5-substituted pyridine, in particular to a method for preparing 2-chloro-5-methylpyridine. The method comprises the following steps: reacting amide as shown in a formula C which is used as a raw material in the presence of a chlorinating agent and N, N-dimethylformamide, and distilling after the reaction is finished to obtain the 5-substituted 2-chloropyridine as shown in a formula I which is described in the specification. When the 5-substituted 2-chloropyridine is prepared from the compound with the structure shown in the formula C, the by-product is allyl chloride (or homologues thereof) with small molecular weight, the boiling point of the by-product is obviously different from that of the product, the reaction conversion rate and the yield are higher than those of the prior art, the by-product is easy to separate from the product, and the by-product is more beneficial to recovery; therefore, according to the preparation method, the equipment investment can be greatly saved, the production cost is reduced, and the operation procedure is simplified; and in the route, the amine with lower price is used as a starting raw material, so that the production cost is reduced.

Two strategies were reported to prevent the deactivation of Frustrated Lewis pairs (FLPs) in the hydrogenation of terminal alkynes: reducing the Lewis acidity and polymerizing the Lewis acid. A polymeric Lewis acid (P-BPh3) with high stability was designed and synthesized. Excellent conversion (up to 99%) and selectivity can be achieved in the hydrogenation of terminal alkynes catalyzed by P-BPh3. This catalytic system works quite well for different substrates. In addition, the P-BPh3 can be easily recycled.

The epoxidation of olefin as a strategy to protect carbon-carbon double bonds is a well-known procedure in organic synthesis, however the reverse reaction, deprotection/deoxygenation of epoxides is much less developed, despite its potential utility for the synthesis of substituted olefins. Here, we disclose a clean protocol for the selective deprotection of epoxides, by combining commercially available organophosphorus ligands and gold nanoparticles (Au NP). Besides being successfully applied in the deoxygenation of epoxides, the discovered catalytic system also enables the selective reduction N-oxides and sulfoxides using molecular hydrogen as reductant. The Au NP catalyst combined with triethylphosphite P(OEt)3 is remarkably more reactive than solely Au NPs. The method is not only a complementary Au-catalyzed reductive reaction under mild conditions, but also an effective procedure for selective reductions of a wide range of valuable molecules that would be either synthetically inconvenient or even difficult to access by alternative synthetic protocols or by using classical transition metal catalysts. This journal is

The invention discloses a chlorinating preparation method for low-carbon olefins. According to the method, chlorine gas is diluted with inert gas and then reacts with low-carbon olefins, thus, influence caused by microscopic mixing can be obviously reduced, namely, a too high local temperature can be avoided, thus, side reactions including a decarbonization phenomenon caused by the too high localtemperature can be obviously reduced, and a relatively good chloride yield can be obtained.

Gold nanoparticles (NPs) combined with Lewis bases, such as piperazine, were found to perform selective hydrogenation reactions via the heterolytic cleavage of H2. Since gold nanoparticles can be prepared by many different methodologies and using different capping ligands, in this study, we investigated the influence of capping ligands adsorbed on gold surfaces on the formation of the gold-ligand interface. Citrate (Citr), poly(vinyl alcohol) (PVA), polyvinylpyrrolidone (PVP), and oleylamine (Oley)-stabilized Au NPs were not activated by piperazine for the hydrogenation of alkynes, but the catalytic activity was greatly enhanced after removing the capping ligands from the gold surface by calcination at 400 °C and the subsequent adsorption of piperazine. Therefore, the capping ligand can limit the catalytic activity if not carefully removed, demonstrating the need of a cleaner surface for a ligand-metal cooperative effect in the activation of H2 for selective semihydrogenation of various alkynes under mild reaction conditions.

Pyrolysis of Au(OAc)3 in the presence of 1,10-phenanthroline over TiO2 furnishes a highly active and selective Au nanoparticle (NP) catalyst embedded in a nitrogen-doped carbon support, Au@N-doped carbon/TiO2 catalyst. Parameters such as pyrolysis temperature, type of support, and nitrogen ligands as well as Au/ligand molar ratios were systematically investigated. Highly selective hydrogenation of numerous structurally diverse alkynes proceeded in moderate to excellent yield under mild conditions. The high selectivity toward the industrially important alkene substrates, functional group tolerance, and the high recyclability makes the catalytic system unique. Both high activity and selectivity are correlated with a frustrated Lewis pairs interface formed by the combination of gold and nitrogen atoms of N-doped carbon that, according to density functional theory calculations, can serve as a basic site to promote the heterolytic activation of H2 under very mild conditions. This "fully heterogeneous" and recyclable gold catalyst makes the selective hydrogenation process environmentally and economically attractive.

The selective hydrogenation of alkynes to alkenes is an important synthetic process in the chemical industry. It is commonly accomplished using palladium catalysts that contain surface modifiers, such as lead and silver. Here we report that the adsorption of nitrogen-containing bases on gold nanoparticles results in a frustrated Lewis pair interface that activates H2 heterolytically, allowing an unexpectedly high hydrogenation activity. The so-formed tight-ion pair can be selectively transferred to an alkyne, leading to a cis isomer; this behavior is controlled by electrostatic interactions. Activity correlates with H2 dissociation energy, which depends on the basicity of the ligand and its reorganization on activation of hydrogen. High surface occupation and strong Au atom-ligand interactions might affect the accessibility and stability of the active site, making the activity prediction a multiparameter function. The promotional effect found for nitrogen-containing bases with two heteroatoms was mechanistically described as a strategy to boost gold activity. (Graph Presented).

The invention discloses a method for synthesizing 2,3,3,3-tetrafluoropropene and belongs to the field of organic synthesis. The method comprises the following steps: (1) preparing 2-chloropropene from 1,2-dichloropropane, which serves as a raw material, through continuous catalytic cracking by adopting a fixed bed in the presence of beta-zeolite, which serves as a catalyst; (2) selectively chlorinating 2-chloropropene with chlorine gas under the catalysis of ferric chloride, so as to prepare 2,3,3,3-tetrachloropropylene; and (3) fluorating 2,3,3,3-tetrachloropropylene with hydrofluoric acid under the catalysis of SbF3 or SbF5, thereby obtaining 2,3,3,3-tetrafluoropropene. The synthesis route has the advantages that the source of raw materials is wide, the cost is low, and the product yield is high; and the obtained product can serve as an automotive air conditioning refrigerant and has a positive significance in reduction of greenhouse effect.

The present disclosure relates to compositions comprising 2,3,3,3-tetrafluoropropene that may be useful as heat transfer compositions, aerosol propellants, foaming agents, blowing agents, solvents, cleaning agents, carrier fluids, displacement drying agents, buffing abrasion agents, polymerization media, expansion agents for polyolefins and polyurethane, gaseous dielectrics, extinguishing agents, and fire suppression agents in liquid or gaseous form. Additionally, the present disclosure relates to compositions comprising 1,1,2,3-tetrachloropropene, 2-chloro-3,3,3-trifluoropropene, or 2-chloro-1,1,1,2-tetrafluoropropane, which may be useful in processes to produce 2,3,3,3-tetrafluoropropene.

The invention discloses a method for preparing propylene by performing oxidative dehydrogenation on propane, and relates to a method for preparing propylene. The method comprises the steps of: heating a catalyst to the temperature of 400 to 700 DEG C, keeping the temperature for 10 to 120 minutes, introducing mixed reaction gas to pass through a catalyst bed layer, and reacting to obtain the product of propylene. The mixed reaction gas propane, oxygen, hydrogen halide gas and inert gas. A small amount of hydrogen halide is introduced into the reaction system to effectively activate the propane, the selectivity of the propylene is more than 80 percent, a once through yield of the propylene is close to 50 percent, and performance of the propylene is much better than the performance of the traditional propylene which is obtained by directly dehydrogenizing and performing oxidative dehydrogenation on the propane; a reaction process is gentle, advanced oxidation for oxidative dehydrogenation of propane to prepare the propylene is greatly suppressed at the presence of halogen hydride, the selectivity of the propylene is greatly improved, and a problem of low selectivity of the propylene at high conversion rate of the propane is solved; and the hydrogen halide is recoverable and reused, energy consumption is low, the employed catalyst is a non-noble metal catalyst, and the components is remained stable during the reaction.

The present invention relates to a method of converting an alcohol into a corresponding halide. This method comprises reacting the alcohol with an optionally substituted aromatic carboxylic acid halide in presence of an N-substituted formamide to replace a hydroxyl group of the alcohol by a halogen atom. The present invention also relates to a method of converting an alcohol into a corresponding substitution product. The second method comprises: (a) performing the method of the invention of converting an alcohol into the corresponding halide; and (b) reacting the corresponding halide with a nucleophile to convert the halide into the nucleophilic substitution product.

Today, one of the problems associated with biodiesel production is the availability of high amount of glycerol byproduct. Among the various possibilities, technology to convert glycerol to dichloropropanol has diverted our attention. Dichloropropanol an important raw material for epichlorohydrin production was successfully synthesized via hydrochlorination reaction of glycerol with aqueous hydrogen chloride to produce 1,3-dichloropropanol. Experimental study was carried out under temperatures ranged; 80 to 120 °C, reactant molar ratio; 1:16 to 1:32 and various carboxylic acid catalysts. The optimal reaction conditions were: temperature, 110 °C; reactant molar ratio glycerol to HCl, 1:24; catalyst, malonic acid; and time duration, 3 h.

TMSOTf-catalyzed intramolecular seleno-arylation of tethered alkenes was performed using polystyrene-supported succinimidyl selenide as the selenium source. This catalytic process provides an efficient method for the regioselective synthesis of dihydrocoumarins possessing a seleno-functionality, followed by traceless cleavage of selenium linker to provide dihydrocoumarins and coumarins in good yields and purities.

The detection and removal of bacteria, such as E. coli in aqueous environments by using safe and readily available means is of high importance. Here we report on the synthesis of nanodiamonds (ND) covalently modified with specific carbohydrates (glyco-ND) for the precipitation of type 1 fimbriated uropathogenic E. coli in solution by mechanically stable agglutination. The surface of the diamond nanoparticles was modified by using a Diels-Alder reaction followed by the covalent grafting of the respective glycosides. The resulting glyco-ND samples are fully dispersible in aqueous media and show a surface loading of typically 0.1 mmol g-1. To probe the adhesive properties of various ND samples we have developed a new sandwich assay employing layers of two bacterial strains in an array format. Agglutination experiments in solution were used to distinguish unspecific interactions of glyco-ND with bacteria from specific ones. Two types of precipitates in solution were observed and characterized in detail by light and electron microscopy. Only by specific interactions mechanically stable agglutinates were formed. Bacteria could be removed from water by filtration of these stable agglutinates through 10 μm pore-size filters and the ND conjugate could eventually be recovered by addition of the appropriate carbohydrate. The application of glycosylated ND allows versatile and facile detection of bacteria and their efficient removal by using an environmentally and biomedically benign material. Copyright

Mild reaction conditions are described for the preparation of a number of alkyl chlorides and 2-dialkyl(aryl)amino-4,6-dirnethoxy-1,3,5-triazines by dealkylation of quaternary triazinylammonium chlorides formed as reactive intermediates in reaction of tertiary amines with 2-chloro-4,6-dimethoxy-1,3,5- triazine. The high selectivity of substitution was observed within the reactivity order of the alkyl groups: benzyl ～ allyl > methyl > n-alkyl. Studies on dealkylation of S-(-)-J-dimethyl-(1-phenylethyl)amine to R-(+)-1-chloro-1-phenylethane revealed that reaction proceeded with an inversion of configuration on the carbon atom as may be expected for SN2 type substitution. The scope of reaction was extended by exchange of anion in quaternary triazinylammonium chlorides with 1-, SCN-, C6H5O-, CH3COO- followed by N-dealkylation step.

An effective and highly chemoselective method is described for the rapid deoxygenation of different epoxides to the corresponding olefins using ZrCl 4/NaI in anhydrous CH3CN, in excellent yields and with retention of relative stereochemistry.

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.

The gas-phase elimination kinetics of 2-substituted ethyl methylcarbonates were determined in a static reaction system over the temperature range of 323-435 °C and pressure range 28.5-242 Torr. The reactions are homogeneous, unimolecular and follow a first-order rate law. The kinetic and thermodynamic parameters are reported. The 2-substituents of the ethyl methylcarbonate (CH3OCOOCH2CH2Z, Z = substituent) give an approximate linear correlation when using the Taft-Topsom method, log(k z/kH)= -(0.57 ± 0.19)σα + (1.34 ± 0.49)σR (r = 0.9256; SD = 0.16) at 400 °C. This result implies the elimination process to be sensitive to steric factors, while the electronic effect is unimportant. However, the resonance factor has the greatest influence for a favorable abstraction of the β-hydrogen of the C3- H bond by the oxygen carbonyl. Because ρα is significant, a good correlation of the alkyl substituents of carbonates with Hancock's steric parameters was obtained: log(kR/kH versus Esc for CH 3OCOOCH2CH2R at 400°C, R = alkyl, δ= -0.17 (r=0.9993, SD = 0.01). An approximate straight line was obtained on plotting these data with the reported Hancock's correlation of 2-alkyl ethylacetates. This result leads to evidence for the β-hydrogen abstraction by the oxygen carbonyl and not by the alkoxy oxygen at the opposite side of the carbonate. The carbonate decompostion is best described in terms of a concerted six-membered cyclic transition state type of mechanism. Copyright

Bis(Fluorophenyl)alkylamides have been chemically synthesized which possess beneficial pharmacological properties (e.g., anticonvulsant activity) useful for the treatment of neurological diseases or disorders, such as, for example, epilepsy, convulsions, and seizure disorders. The preferred compounds of the invention also cause little sedation and have high therapeutic and protective indices in animal models of epilepsy. These compounds further possess long pharmacological half-lives, which, in practical clinical therapeutic application, should translate into once-a-day dosing, of great benefit to patients suffering from these diseases and/or disorders. These compounds may also be of further clinical utility in the treatment of other diseases and disorders of the central and peripheral nervous systems, or diseases or disorders affected by them, including, but not limited to, spasticity, skeletal muscle spasms and pain, restless leg syndrome, anxiety and stress, and bipolar disorder.

A process for the preparation of a mixture comprising a compound of formula (1) and a compound of formula (2) wherein R1is an optionally substituted C1-20alkyl, optionally substituted C3-4alkenyl, optionally substituted C5-7cycloalkyl or optionally substituted benzyl, R2is an optionally substituted C1-20alkyl, optionally substituted C3-4alkenyl or optionally substituted C5-7cycloalkyl, A is either S or NR3, R3is an optionally substituted C1-20alkyl, optionally substituted C3-4alkenyl or optionally substituted C5-7cycloalkyl, or R2and R3together form a 5-7 membered ring which can contain an oxygen atom, R4is hydrogen or methyl, R5is an optionally substituted C1-20alkyl, optionally substituted C3-4alkenyl, optionally substituted C5-7cycloalkyl or optionally substituted benzyl and, R6is hydrogen or an optionally substituted C1-20alkyl, optionally substituted C3-4alkenyl or optionally substituted C5-7cycloalkyl, or R5and R6together form a 5-7 membered ring which can contain an oxygen atom, which comprises reacting in an alkaline or base medium a compound of formula (3) wherein X?is an anion, R1, R2, R3, R4, R5and R6have the same meaning as above, A+is S+or N+R3.

The invention concerns a method for functionalizing a phenolic compound bearing an electron-donor group, in said group para position, inter alia a method for the amidoalkylation of a phenolic compound bearing an electron-donor group, and more particularly, a phenolic compound bearing an electron-donor group preferably, in the hydroxyl group ortho position. The method for functionalizing in para position with respect to an electron-donor group carried by a phenolic compound is characterised in that the phenolic compound bearing an electron-donor group is subjected to the following steps: a first step which consists of protecting the hydroxyl group in the form of a sulphonic ester function; a second step which consists in reacting the protected phenolic compound with an electrophilic reagent; optionally, a third step deprotecting the hydroxyl group.

Flash vacuum pyrolysis over a bed of freshly sublimed magnesium on glass wool results in efficient coupling of benzyl halides to give the corresponding bibenzyls. Where an ortho halogen substituent is present further dehalogenation gives some dihydroanthracene and anthracene. Efficient coupling is also observed for halomethylnaphthalenes and halodiphenylmethanes while chlorotriphenylmethane gives 4,4′-bis(diphenylmethyl)biphenyl. By using α,α′-dihalo-o-xylenes, benzocyclobutenes are obtained in good yield, while the isomeric α,α′-dihalo-p-xylenes give a range of high thermal stability polymers by polymerisation of the initially formed p-xylylenes. Other haloalkylbenzenes undergo largely dehydrohalogenation where this is possible, in some cases resulting in cyclisation. Deoxygenation is also observed with haloalkyl phenyl ketones to give phenylalkynes as well as other products. With simple alkyl halides there is efficient elimination of HCl or HBr to give alkenes. For aliphatic dihalides this also occurs to give dienes but there is also cyclisation to give cycloalkanes and dehalogenation with hydrogen atom transfer to give alkenes in some cases. For 5-bromopent-1-ene the products are those expected from a radical pathway but for 6-bromohex-1-ene they are clearly not. For 2,2-dichloropropane and 1,1-dichloropropane elimination of HCl occurs but for 1,1-dichlorobutane, -pentane and -hexane partial hydrolysis followed by elimination of HCl gives E, E-, E,Z- and Z,Z- isomers of the dialk-1-enyl ethers and fully assigned 13C NMR data are presented for these. With 6-chlorohex-1-yne and 7-chlorohept-1-yne there is cyclisation to give methylenecycloalkanes and -cycloalkynes. The behaviour of 1,2-dibromocyclohexane and 1,2-dichlorocyclooctane under these conditions is also examined. Various pieces of evidence are presented that suggest that these processes do not involve generation of free gas-phase radicals but rather surface-adsorbed organometallic species.

A novel method is described for the conversion of epoxides into β-bromoformates using Ph3PBr2, Ph3P/N-bromosuccinimdes (NBS) and or Ph3P/2,4,4,6-tetrabromo-2,5-cyclohexadiene-1-one (TABCO) in DMF. Epoxides in the presence of Ph3P/I2 were converted into olefins immediately in excellent yields. The application of NBS, NCS, and TABCO as compounds carrying electrophilic halogens for the highly selective alcoholysis of epoxides and dimerization or alcoholysis dimerization of episulfides are also described.

The present invention relates to derivatives and analogues of adenine, which inhibit adenylyl cyclase activity. The present invention also relates to a method of preventing and inhibiting a patient's fibroproliferative vasculopathy following vascular injury or a vascular surgical operation which includes administering to the patient, an effective amount of a compound according to the invention subsequent to a vascular injury, or subsequent to a vascular surgical operation, for one to two weeks after the injury or surgical operation, effective to treat or prevent a patient's fibroproliferative vasculopathy such as chronic allograft rejection or vascular restenosis following vascular trauma. The present invention also relates to a method for measuring the inhibition of adenylyl cyclase activity and a method for treating congestive heart failure.

The reactivity of bismuth(III) halides (BiX3; X=Cl, Br and I) towards a series of alcohols has been investigated. Three different reactions have been studied, namely: halogenation, dehydration and etherification. The behaviour of these bismuth derivatives was found to depend on the nature of the halide bonded to the bismuth atom. Their reactivities can be interpreted on the basis of the Hard and Soft Acids and Bases (HSAB) principle. A mechanism is proposed which involves the formation of a complex of the alcohol with Bi(III).

The elimination kinetics of 17 2-substituted ethyl N,N-dimethylcarbamates in the gas phase were determined in the temperature range of 269.5-420.2°C and the pressure range of 24-186 Torr. The reactions in a static system and in the presence of a free radical inhibitor are homogeneous and unimolecular and follow a first-order rate law. The kinetics and thermodynamic parameters are described. The use of several structure-reactivity relationship methods meaningless results, except for Taft σ* values. Three good slopes are originated at σ*(CH3) = 0.00. Slope a: the 2-substituted alkyl groups gave a good straight line when log (k/kCH3) vs σ* values (ρ* = - 1.94 ± 0.30, r = 0.977 at 360°C) were plotted. Slope b: Polar2 substituents gave an approximate straight line with ρ* = - 0.12 ± 0.02, r = 0.936 at 360°C. Slope c:the correlation of multiple bonded and electron-withdrawing substituents interposed by a methylene group at the 2-position of ethyl N,N-dimethylcarbamate was found to give a very good straight line wirh ρ* = 0.49 ± 0.02, r = 0.991 at 360°C. Mechanisms are suggested on the basis of these relationships. The point position of the substituents phenyl (C6H5) and isopropenyl [CH2=C(CH3)] at the 2-position was found to fall far above the three slopes of the lines. These results are interpreted in terms of neighboring group participation of these substituents in the elimination process of the carbamates. However, the acidity of the benzylic and allylic Cβ-H bond for a six-membered cyclic transition state may not be ignored. Copyright

The reaction of tertiary phosphine oxides with phosphorus oxychloride was found to give triorganylphosphonium dichlorophosphates R3PCl+PO2Cl-2 rather than phosphorylphosphonium salts R3P · OPOCl2. Mixtures of the reagents, called binary system, possess a considerable synthetic potential. They are capable of converting alcohols to the corresponding alkyl chlorides.

cis-Bis(alkenyl)iridium complexes cis,trans-[IrR(-CH=CH+PPh3)2(CO)(PPh 3)2]2+ (2, R = H (a), CH3 (b), Cl (c)) have been prepared from the reactions of dihaloiridium(III) compounds with HC≡CH and PPh3. Reactions of 2b and 2c with CH2=CHCH2Br give bis(alkenyl)-(PPh3)iridium, cis-[IrBr(CH3)(-CH=CH+PPh3) 2(CO)(PPh3)]+, and cis,cis-[IrBr2(-CH=CH+PPh3) 2(CO)(PPh3)]+. Crystal structures of 2c and [Ir(OClO3)(CH3)(H2O)(CO)(PPh3) 2]+ (4) have been determined by X-ray diffraction data analysis.

Bismuth halides are efficient and selective reagents in the halogen exchange reactions carried out under mild conditions. This rapid, high yield reaction proceeds mainly with retention of configuration.

Dehydrochlorination of 1,2-dichloropropane (DCP) was conducted by thermal elimination and CO2 laser-reduced dielectric breakdown, which was induced by focusing the 10.6 μm lines of a CO2 TEA laser. Thermal dehydrochlorination proceeded by a four-centered mechanism at > 425 °C and by a surface-catalyzed radical process at 2000 °C.

The subject is to provides a process for producing 1-substituted-hydantoins of Formula I: STR1 wherein R1 represents d hydrocarbon group which may be substituted and others, cheracterized by reacting N-sustituted-N-alkcycarbonylamnilo-acetonitrile of Formula II: STR2 wherein R2 represents an alkyl group and others, with an alkali metal hydroxides or the like and then treating with an acid.

Mono- or polycarboxylic acid esters are prepared by reacting a salt of such carboxylic acid with an organic halocompound, e.g., a (cyclo)alkyl, (cyclo)alkenyl, aryl or aralkyl halide, in an aqueous reaction medium, in the presence of a catalytically effective amount of a phase transfer catalyst, for example an onium salt.

The subject is to provides a process for producing 1-substituted-hydantoins of Formula I: wherein R1represents a hydrocarbon group which may be substituted and others,characterized by reacting N-substituted-N-alkoxycarbonylamino-acetonitrile of Formula II: wherein R2represents an alkyl group and others,with an alkali metal hydroxides or the like and then treating with an acid.

Using the method of competitive reactivity of two functional groups in the same molecule, anionic elimination reactions show considerable kinetic selectivity for small differences in leaving group thermochemistry, in structures of the general type YCH2CH2CH2Z, where Y and Z are good anionic leaving groups.

A process for producing a colorless unsymmetrical-diester of maleic acid, useful as a raw material of an emulsifier for emulsion polymerization and as a modifier for a polymer, which comprises: (1) reacting maleic anhydride with a monohydric alcohol in the presence of an inert organic solvent, in a molar ratio of 1:(1.0-1.2) to obtain maleic acid mono ester containing substantially no unreacted maleic anhydride, and (2) reacting said monoester with an alkenyl halide in the presence of a tertiary amine and water, in a molar ratio of said monoester:water of 1:(0.01-0.20).

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In the presence of catalytic amount of BiCl3, chloromethylsylanes can be used as chlorinating agents for alcohols, and as chloro-dealkylating agents for silyl ethers and carboxylic and sulfonic esters.The chlorination of (R)-(-)-octan-2-ol and the (R)-(-)-2-mesyloctane by TMSCl gave predominantly the (S)-(+)-2-chlorooctane with inversion of configuration at secondary carbon.According to the class of alcohol, the mechanism involves SN2, SN2' or SN1 processes.This new activation of the Si-Cl bond, probably trough a Si-Cl...BiCl3 interaction gives a hard-soft reagent that can generate a silicenium cation, was also observed with Me3SiBr, BiBr3 and Me3SiI, BiI3 systems.The reaction is also presented as a possible alcoholysis of chlorosilanes, which can lead to siloxanes in non-aqueous conditions. catalysis / halogenation / alcohol / ester / silyl ether / chlorosilane / chlorotrimethylsilane / bromotrimethylsilane / iodotrimethylsilane / siloxane / bismuth (III) halide

Pyrolysis of 1,2-dichloropropane at 480-560 deg C and with a contact time of up to 10 sec has been studied, and kinetic characteristics of the process have been determined.

The present invention relates to the use of an allylchloride of the general formula STR1 wherein R is a C1 -C12 alkyl group or a C2 -C12 alkenyl group, which groups may be substituted with one or more substitutents selected from the group consisting of C1 -C4 alkoxy, halogen, unsubstituted phenyl and substituted phenyl; a (trihydrocarbyl)silyl group; a (dihydrocarbyl) (hydrocarbyloxy)silyl group; or a dihydropyran-2-yl group, a tetrahydropyran-2-yl group, a dihydrofur-2-yl group or a tetrahydrofur-2-yl group, which groups may be substituted with C1 -C6 alkyl; for preparing an aldehyde compound via an intermediate alcohol compound. The invention further relates to a new allylchloride.

In the presence of a catalytic amount of dichlorotris(triphenylphosphine)ruthenium(II), the reactions of arenesulfonyl chlorides with allyl phenyl sulfide and allyl phenyl selenide proceeded smoothly to give allyl phenyl sulfone in high yield as well as the corresponding diphenyl disulfide or diphenyl diselenide.An SH2'-type mechanism involving the arenesulfonyl radical is proposed.

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This paper describes the successful preparation of new Ru(IV)-π-allyl complexes having the general formula (C5R5)RuX2(η3-allyl) (R = H, Me; X = Cl, Br) by the oxidative addition of allylic halides to Ru(II) complexes, (C5R5)Ru(L)2X (R = H, Me; L = CO, PPh3; X = Br, Cl). These new compounds were subjected to NMR analysis to determine the structure, which was confirmed by X-ray crystallographic analysis of a representative compound. During the course of this study, the authors found facile reductive elimination of allylic halides from the Ru(IV)-π-allyl complexes to form Ru(II)-carbonyl or Ru(II)-arene complexes, induced by contact with CO or aromatic solvents, respectively.

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Chemical, kinetic, and stereochemical studies of the metatheses between CCl4 and η-CpFe(CO)2CH2CH=CR2 (R = H, Me) show that the reaction proceeds via a radical chain mechanism that involves the generation of the initiating radicals by a prequilibrium homolysis of the iron-allyl bond in the starting material. The ultimate product is formed by an SH2′ reaction between ?CCl3 and η-CpFe(CO)2CH2CH=CR2. The reaction follows a rate law with an unusual 5/3 total order: rate = kobsd[η-CpFe(CO)2CH2CH= CH2][CCl4]2/3.

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