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4-vinylpyridine production

The fast and sufficiently complete reaction proceeds in dimethyl sulfoxide, dimethylformamide, hexamethylphosphotriamide, and excess 4-vinylpyridine, but the best results were achieved in N-methyl-N-butylimi-dazolium tetrafluoroborate, an ionic liquid. The final polymers demonstrate a noticeable volume increase by taking up as much organic solvents, both polar and nonpolar, and even water, as a hypercrosslinked polystyrene crosslinked with the same crosslinking agent (Table 9.4). Still, the specific surface area of the hydrophilic hypercrosslinked polymer is smaller than that of the hypercrosslinked polystyrene, being less than 100 m/g. In all probability, the rigidity of the hypercrosslinked vinylpyridine product is... [Pg.337]

Resin and Polymer Solvent. Dimethylacetamide is an exceUent solvent for synthetic and natural resins. It readily dissolves vinyl polymers, acrylates, ceUulose derivatives, styrene polymers, and linear polyesters. Because of its high polarity, DMAC has been found particularly useful as a solvent for polyacrylonitrile, its copolymers, and interpolymers. Copolymers containing at least 85% acrylonitrile dissolve ia DMAC to form solutions suitable for the production of films and yams (9). DMAC is reportedly an exceUent solvent for the copolymers of acrylonitrile and vinyl formate (10), vinylpyridine (11), or aUyl glycidyl ether (12). [Pg.85]

The relative production volumes of pyridine compounds can be ranked in the following order pyridine (1) > P-picoline (3) > a-picoline (2)> niacin (27) or niacinamide (26)> 2-vinylpyridine (23)> piperidine (18). U.S. and Japanese production was consumed internally as well as being exported, mainly to Europe. European production is mosdy consumed internally. Growth in production of total pyridine bases is expected to be small through the year 2000. [Pg.333]

The main use of y-picoline (4) is in the production of the antituberculosis agent, isonia2id (31). Compound (4) is also used to make 4-vinylpyridine, and subsequendy polymers. [Pg.336]

Synthetic. The main types of elastomeric polymers commercially available in latex form from emulsion polymerization are butadiene—styrene, butadiene—acrylonitrile, and chloroprene (neoprene). There are also a number of specialty latices that contain polymers that are basically variations of the above polymers, eg, those to which a third monomer has been added to provide a polymer that performs a specific function. The most important of these are products that contain either a basic, eg, vinylpyridine, or an acidic monomer, eg, methacrylic acid. These latices are specifically designed for tire cord solutioning, papercoating, and carpet back-sizing. [Pg.253]

Pyridinium ylide is considered to be the adduct car-bene to the lone pair of nitrogen in pyridine. The validity of this assumption was confirmed by Tozume et al. [12J. They obtained pyridinium bis-(methoxycarbonyl) meth-ylide by the photolysis of dimethyl diazomalonate in pyridine. Matsuyama et al. [13] reported that the pyridinium ylide was produced quantitatively by the transylidalion of sulfonium ylide with pyridine in the presence of some sulfides. However, in their method it was not easy to separate the end products. Kondo and his coworkers [14] noticed that this disadvantage was overcome by the use of carbon disulfide as a catalyst. Therefore, they used this reaction to prepare poly[4-vinylpyridinium bis-(methoxycarbonyl) methylide (Scheme 12) by stirring a solution of poly(4-vinylpyridine), methylphenylsulfo-nium bis-(methoxycarbonyl)methylide, and carbon disulfide in chloroform for 2 days at room temperature. [Pg.375]

The structures of these ylide polymers were determined and confirmed by IR and NMR spectra. These were the first stable sulfonium ylide polymers reported in the literature. They are very important for such industrial uses as ion-exchange resins, polymer supports, peptide synthesis, polymeric reagent, and polyelectrolytes. Also in 1977, Hass and Moreau [60] found that when poly(4-vinylpyridine) was quaternized with bromomalonamide, two polymeric quaternary salts resulted. These polyelectrolyte products were subjected to thermal decyana-tion at 7200°C to give isocyanic acid or its isomer, cyanic acid. The addition of base to the solution of polyelectro-lyte in water gave a yellow polymeric ylide. [Pg.378]

If the more activated alkene 2-vinylpyridine is used in place of styrene with the same catalysts and the same range of substrates, anti-Markovnikoff hydroamination is also found. Thus, N-[2-(2 -pyridyl)ethyl]piperidine was isolated in 53% yield from reaction of 2-vinylpyridine with piperidine in the presence of [Rh(COD)2]+/2PPh3 under reflux. N H addition was observed with other amines, the remaining product in all cases being primarily that from oxidative amination (Table 12). When the catalytic reaction was run in the absence of phosphine, the yield of hydroamination product increased dramatically.171... [Pg.292]

Vinylpyridines react with a variety of ADC compounds. The initial Diels-Alder adducts can be isolated, although in many cases the major product contains two molecules of the ADC compound.186,187 Similarly, 2-vinylthiophenes react to give both 1 1 and 1 2 adducts,188 189 and 3-vinylindoles to give 1 1 adducts.190 ... [Pg.36]

A Michael-type addition reaction of phosphine generated from red phosphorus in concentrated aqueous KOH solution has been noted to provide moderate isolable yields of pure organophosphorus products.27 For example, tris-(2-cyanoethyl)phosphine is produced in 45% isolable yield from acrylonitrile, and tris-(2-[y-pyridyl]ethyl) phosphine oxide is isolated in 40% yield from 4-vinylpyridine under these conditions. Excellent yields of the tertiary phosphine oxide, tris-(2-cyanoethyl)phosphine oxide, have been reported using white phosphorus in absolute ethanol with KOH at ice/salt-bath temperatures.28 A variety of solvent systems were examined for this reaction involving a Michael-type addition to acrylonitrile. Similarly, tris-(Z-styryl)phosphine is produced from phenylacetylene under these conditions in 55% isolated yield. It is noteworthy that this last cited reaction involves stereospecific syn- addition of the phosphine to the alkyne. [Pg.30]

This alkylation reaction can be applied to intramolecular alkylation affording cyclic products, as shown in Equations (19)-(21). The reaction of 2-vinylpyridines with 1,5- or 1,6-dienes results in the formation of five- or six-membered carbocycles with good efficiency.20,20a,20b In addition to pyridine functionality, oxozole and imidazole rings can be applied to this intramolecular cyclization. When the reaction is conducted in the presence of a monodentate chiral ferrocenylphosphine and [RhCl(coe)2]2, enantiomerically enriched carbocycles are obtained. A similar type of intramolecular cyclization is applied to TV-heterocycles. The microwave irradiation strongly... [Pg.217]

Colloidal catalysts in alkyne hydrogenation are widely used in conventional solvents, but their reactivity and high efficiency were very attractive for application in scC02. This method, which is based on colloidal catalyst dispersed in scC02, yields products of high purity at very high reactions rates. Bimetallic Pd/Au nanoparticles (Pd exclusively at the surface, while Au forms the cores) embedded in block copolymer micelles of polystyrene-block-poly-4-vinylpyridine... [Pg.240]

It is natural that the participation of N02 and NO+ in the one-electron oxidation puts forward the target of NO2 and NO determination. The direct determination of these gaseous products presents some problems. IR spectroscopy is a method (see, e.g., Todres et al. 1988), but this method is not always convenient or even available. The direct determination of NO2 and NO by ESR spectroscopy is not possible owing to the short relaxation time, which gives rise to broad absorption lines. Spin trapping of NO combined with ESR is recommended for this purpose (Norby et al. 1997). As an effective spin trap for NO2, poly(2-vinylpyridine) has been recently proposed (Davydov et al. 2006). [Pg.67]

The total consumption of 2-methylpyridine (a-picoline) in 1980 has been estimated at 12,000 tons [81CI(L)23]. Half is produced for the U.S. market, whereas the demand in both Western Europe and Japan lies between 2000 and 2500 tons per annum. A significant outlet for 2-methylpyridine is in the production of 2-chloro-6-(trichloromethyl)pyri-dine, which is used as a nitrification inhibitor in agricultural chemistry and in the manufacture of the defoliant 4-amino-2,5,6-trichloropicolinic acid. The major commercial outlet for 2-methylpyridine is, however, its use as a starting material for the production of 2-vinylpyridine [Eq.(7)]. [Pg.185]

As in the synthesis of other bipyridines, several routes to 4,4 -bipyridine have been devised where one of the pyridine rings is built up from simpler components. For example, a dimer of acrolein reacts with ammonia and methanol in the presence of boron phosphate catalyst at 350°C to give a mixture of products including 4,4 -bipyridine (3.4% yield), and in a reaction akin to ones referred to with other bipyridines, 4-vinylpyridine reacts with substituted oxazoles in the presence of acid to give substituted 4,4 -bipyridines. ° ° Condensation of isonicotinaldehyde with acetaldehyde and ammonia at high temperatures in the presence of a catalyst also affords some 4,4 -bipyridine, and related processes give similar results,whereas pyran derivatives can be converted to 4,4 -bipyridine (56% conversion), for example, by reaction with ammonia and air at 350°C with a nickel-alumina catalyst. Likewise, 2,6-diphenyl-4-(4-pyridyl)pyrylium salts afford 2,6-... [Pg.328]

Vinylpyridine (44) exhibits many of the properties of a Michael acceptor. Thus, this molecule will undergo conjugate addition of methoxide ion and the product, methyridine,... [Pg.515]

Spontaneous polymerization of 4-vinyl pyridine in the presence of polyacids was one of the earliest cases of template polymerization studied. Vinyl pyridine polymerizes without an additional initiator in the presence of both low molecular weight acids and polyacids such as poly(acrylic acid), poly(methacrylic acid), polyCvinyl phosphonic acid), or poly(styrene sulfonic acid). The polyacids, in comparison with low molecular weight acids, support much higher initial rates of polymerization and lead to different kinetic equations. The authors suggested that the reaction was initiated by zwitterions. The chain reaction mechanism includes anion addition to activated double bonds of quaternary salt molecules of 4-vinylpyridine, then propagation in the activated center, and termination of the growing center by protonization. The proposed structure of the product, obtained in the case of poly(acrylic acid), used as a template is ... [Pg.27]

A template mechanism was also proposed for spontaneous polymerization of propargyl chloride in the presence of poly(4-vinylpyridine). The reaction consists of partial (6-8%) alkylation of P4VPy by propargyl chloride which leads to stable complex P4VPy with monomer and then to polymerization. The product obtained contains a conjugated bond system formed by opening triple bonds in the monomer according to reaction ... [Pg.46]

The authors found that 4- and 2-vinylpyridines and N,N-dimethylaminostyrene polymerize spontaneously at 50°C in DMF or acetone in the presence of poly(maleic anhydride). Product obtained consist of 1 1 mixture of poly(vinylpyridine) and the template. Moreover, degree of polymerization of daughter polymer was almost the same as degree of polymerization of the template used. After separation of the polymerization product, it was found that for PVP, P = 14, whereas for poly(maleic anhydride) used as a template, Pn = 12. [Pg.48]

In radical template polymerization, when only weak interaction exists between monomer and template and pick-up mechanism is commonly accepted, the reaction partially proceeds outside the template. If macroradical terminates by recombination with another macroradical or primary radical, some macromolecules are produced without any contact with the template. In fact, such process can be treated as a secondary reaction. Another very common process - chain transfer - proceeds simultaneously with many template polymerizations. As a result of chain transfer to polymer (both daughter and template) branched polymers appear in the product. The existence of such secondary reactions is indicated by the difficulty in separating the daughter polymer from the template as described in many papers. For instance, template polymerization of N-4-vi-nyl pyridine is followed, according to Kabanov et aZ., by the reaction of poly(4-vinylpyridine) with proper ions. The reaction leads to the branched structure of the product ... [Pg.85]

Poly(4-vinylpyridine) (10 mmol) having an Mn 300,000 Da was dried and then treated with l,l,l,2,2,3,3,4,4,5,5,6,6-tridecafluoro-8-iodooctane (12mmol) and the mixture reacted for 48 hours at 80°C in 50 ml N,N -dimethyIformamide. The solution was precipitated by pouring into ethyl acetate and then washed with petroleum ether. The material was dried under vacuum for 24 hours at 60°C and the product isolated in 90% yield. [Pg.30]

Rodrigues et al. (4) prepared polymeric ionic liquid derivatives, (VI), by condensing poly(4-vinylpyridine) with propane sultone and products used as antidye transfer agents. [Pg.36]

Relatively few hydroformylations using supported cobalt complexes have been reported. Moffat (78, 79) showed that poly-2-vinylpyridine reversibly reacted with both Co2(CO) and HCo(CO)4, the cobalt carbonyl being displaced by excess carbon monoxide. This enabled the polymer to pick up the cobalt carbonyl at the end of the reaction and, thus, allowed it to be separated from the products by filtration. The polymer acted as a catalyst reservoir by rapidly releasing the cobalt carbonyl into solution in the presence of further carbon monoxide, so that the actual catalysis was a homogeneous process. More recently, cobalt carbonyl has been irreversibly bound to a polystyrene resin... [Pg.219]

The Heck reactions depicted so far all involve the coupling of halopyridines and other olefins. The alternate approach, coupling of a vinylpyridine with an aryl halide is also feasible, although less commonly employed. 4-Vinylpyridine was coupled successfully with diethyl 4-bromobenzylphosphonate (7.50.) in the presence of a highly active catalyst system consisting of palladium acetate and tn-o-tolylphosphine to give the desired product in 89% yield, which was used for grafting the pyridine moiety onto metal oxides.70... [Pg.158]

Further studies on the 1,3-dipolar cycloadditions of these molecules (86) have been reported. Addition of allyl alcohol gives endo adducts (505) which are not isolated but spontaneously cyclize to tricyclic products (506). Similar tricyclic products were also obtained using A-allylbenzenesulfonamide, triethylammonium acrylate, and vinylpyridines as dipolarophiles. It has previously been shown that the pyridinium-3-olates with chloroketenes (RCC1=C=O) give 2-oxofuro [2,3-c] pyridine 507 (see p. 22). Further studies demonstrate that when bromoketenes (RCBr=C=O) are used as dipolarophiles, a mixture of 2-oxofuro[2,3-c]pyridines (507) and isomeric... [Pg.106]

Hydrazones are transformed into gcw-difluoro compounds by treatment with a combination of 60% hydrogen fluoride/pyridine or 59% hydrogen fluoride/poly-4-vinylpyridine and N-bromosuccinimide yields are satisfactory.170 The electrochemical reaction of diarylketone hydrazones 1 in the presence of triethylamine trisfhydrogen fluoride) complex in dichloromethane solution (current density 1.3 mA cm"2) gives mainly the monofluorinated products 2 besides only very small amounts of difluorides 3.332... [Pg.121]

Substitution of hydrogen by fluorine in compounds with acidic a-hydrogens can be achieved with xenon difluoride and some catalysts. Thus, room-temperature fluorination of 1,3-diketones, e g. 20, with xenon difluoride in the presence of the insoluble cross-linked polysty-rene-4-vinylpyridine, either complexed with boron trifluoridc or Nafion-H, as catalyst, gives mono and difluoro products.27-28... [Pg.603]


See other pages where 4-vinylpyridine production is mentioned: [Pg.143]    [Pg.341]    [Pg.341]    [Pg.186]    [Pg.125]    [Pg.178]    [Pg.357]    [Pg.629]    [Pg.200]    [Pg.417]    [Pg.168]    [Pg.165]    [Pg.357]    [Pg.264]    [Pg.178]    [Pg.339]    [Pg.188]    [Pg.153]    [Pg.177]    [Pg.123]    [Pg.187]    [Pg.654]    [Pg.240]   
See also in sourсe #XX -- [ Pg.276 ]




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