5-Ethyl-2-vinylpyridine

Q=1.30r e=-0.50 for 2-vinylpyridine, and Q=1.37, e=-0.74 for the other pyridine these are given in Table II. The monomer-copolymer compostion curve calculated from the monomer reactivity ratios, ri=0.514 and r2=0.715, gave a poorer fit to the experimental points with 4-vinylpyridine. To describe the data obtained with 2-vinylpyridine, the calculated curve with Q=1.5 and e=-1.2 was poorer fit than that with Q=1.4 and e=-l.l, but better than that with Q=1.2 and e=-1.0 for 1-ethenyl-4-(2,3-epoxy-l-propoxy)benzene. These calculated with Q=1.5, e=-1.2 Q=1.3, e=-l.l and Q=1.2, e=-l.0 for 1-ethenyl-4-(2,3-epoxy-l-propoxy)benzene gave an excellent fit corresponding closely to the points with 5-ethyl-2-vinylpyridine. 

Fiber dye assist resins 5-Ethyl-2-vinylpyridine Italy 545,417 1956 Montecatini... 

Ethyl-(/ -vinylphenyl)thiophosphorochloridate, MA copolymerization, 373 5-Ethyl-2-vinylpyridine, MA copolymerization, 660... 

TABLE 1 Emission lifetimes (in aerobic aqueous solution), Stem Volmer constants and rate constants for quenching by MV2+ of the excited [Ru(bpy3]2+—like centre of the N-ethylated vinylpyridine copolymer at various salt concentrations. 

Indoles can also be alkylated by conjugate addition under alkaline conditions. Under acidic conditions, alkylation normally occurs at C3 (see Section 11.1). Table 9.1 includes examples of alkylation by ethyl acrylate, acrylonitrile, acrylamide and 4-vinylpyridine. 

Strauss and Williamst have studied coil dimensions of derivatives of poly(4-vinylpyridine) by light-scattering and viscosity measurements. The derivatives studied were poly(pyridinium) ions quaternized y% with n-dodecyl groups and (1 - y)% with ethyl groups. Experimental coil dimensions extrapolated to 0 conditions and expressed relative to the length of a freely rotating repeat unit are presented here for the molecules in two different environments ... 

Poly(4-vinylpyridine) [25232-41-1] M (105.1)n. Purified by repeated pptn from solns in EtOH and dioxane, and then EtOH and ethyl acetate. Finally, freeze-dried from rcrt-butanol. 

Reactions of 3- and 4-piperidone-derived enamines with a dienester gave intermediates which could be dehydrogenated to tetrahydroquinolines and tetrahydroisoquinolines (678). The methyl vinyl ketone annelation of pyrrolines was extended to an erythrinan synthesis (679). Perhydrophenan-threnones were obtained from 1-acetylcyclohexene and pyrrolidinocyclo-hexene (680) or alternatively from Birch reduction and cyclization of a 2-pyridyl ethyl ketone intermediate, which was formed by alkylation of an enamine with a 2-vinylpyridine (681). 

On the other hand, poly(ethoxycarbonylimino-4-vi-nylpyridinium ylide) (Scheme 13) was prepared essentially by the same method from 1-ethoxycarbonylimino-pyridinium ylide, as described by Hafner [15] from the reaction of poly (4-vinylpyridine) with nitrene, generated from the pyrolysis of ethyl azidoformate. 

Nucleic acids are anionic under the neutral conditions. Thus, the syntheses of model compounds of the opposite charge are interesting for the discussion of electrostatic contributions in specific interactions of nucleic acids. We have tried to synthesize cationic models by the Menschutkin reaction of poly-4-vinylpyridine with 9-(2-chlo-roethyl)adenine, l-(2-chloroethyl)thymine, and 7-(2-chloroethyl)theophylline15,16 The obtained polymers are poly l-[2-(adenin-9-yl)ethyl]-4-pyridinioethylene chloride 7(APVP), poly l-[2-(thymin-l-yl)ethyl]-4-pyridinioethylene chloride 8 (TPVP), and poly l-[2-(theophyllin-7-yl)ethyl]-4-pyridiniothylene chloride 9 (THPVP), respectively. 

Cordes et al995 carried out alkaline hydrolyses of p-nitrophenylhexanoate 55 (PNPH) in the presence of poly-4-vinylpyridine partially quaternized with dodecyl-bromide and ethylbromide (QPVP). They also found that the polyelectrolytes are increasingly effective as catalysts with an increasing ratio of dodecyl to ethyl groups, and the hydrophobic interactions are important in determining the catalytic efficiency. They observed the inhibitory effects of several gegen-anions fluoride ions are the weakest inhibitor, and nitrate is the strongest (F- < Cl < S04 [Pg.159]

Borabenzene complexes of cobalt such as Co(C5H5BPh)(COD) (51) and its 5-ethyl analog show the same type of catalysis but improved activity and chemoselectivity (77). Thus, 51 as the catalyst precursor gave the hitherto best results in the catalytic synthesis of the valuable 2-vinylpyridine from C2H2 and CH2=CHCN (120°C, 51 bar, 2 hours, turnover number 2164) (77,101). Furthermore, this catalyst for the first time allowed the synthesis of pyridine from C2H2 and HCN under mild conditions (110°C, 23 bar, 60 minutes, turnover number 103) (77). 

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... 

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. 

Penultimate effects have been observed for many comonomer pairs. Among these are the radical copolymerizations of styrene-fumaronitrile, styrene-diethyl fumarate, ethyl methacrylate-styrene, methyl methacrylate l-vinylpyridine, methyl acrylate-1,3-butadiene, methyl methacrylate-methyl acrylate, styrene-dimethyl itaconate, hexafluoroisobutylene-vinyl acetate, 2,4-dicyano-l-butene-isoprene, and other comonomer pairs [Barb, 1953 Brown and Fujimori, 1987 Buback et al., 2001 Burke et al., 1994a,b, 1995 Cowie et al., 1990 Davis et al., 1990 Fordyce and Ham, 1951 Fukuda et al., 2002 Guyot and Guillot, 1967 Hecht and Ojha, 1969 Hill et al., 1982, 1985 Ma et al., 2001 Motoc et al., 1978 Natansohn et al., 1978 Prementine and Tirrell, 1987 Rounsefell and Pittman, 1979 Van Der Meer et al., 1979 Wu et al., 1990 Yee et al., 2001 Zetterlund et al., 2002]. Although ionic copolymerizations have not been as extensively studied, penultimate effects have been found in some cases. Thus in the anionic polymerization of styrene t-vinylpyri-dine, 4-vinylpyridine adds faster to chains ending in 4-vinylpyridine if the penultimate unit is styrene [Lee et al., 1963]. 

Yount et al. (2005) reported the formation of organogels using poly(vinylpyridine) (PVP) and ditopic metallopincer cross-linkers. This study provided particularly pertinent information on the dynamic elements of MSPs and elegantly demonstrated how they control the material s properties. PVP dissolved in dimethylsulfoxide (DMSO) is cross-linked with either bis-Pd - (18a) or Pt -pincer compounds (18b, Fig. 7.13 Yount et al. 2005). Addition of 5% 18a -Pd to a PVP solution results in a viscous material (77 = 6.7 Pa s), whereas the corresponding PVP 18b Pd is a gel (77 = 550 Pa s). Changing R from methyl to ethyl does not affect the thermodynamics of the pyridine/Pd interaction however, the rate of exchange decreases by approximately 2 orders of magnitude. Further studies on these materials and their... 

Acid hydrolysis under standard conditions (6M HC1, 110 °C, 24 h) leads to partial decomposition of selenocystine and selenocysteine derivatives, thus making quantification of this amino acid by amino acid analysis difficult. Similarly, acid hydrolysis of 5e-[2-(4-pyr-idinyl)ethyl]selenocysteine peptides, obtained by reduction of the selenocystine peptides with NaBH4 and reaction with 4-vinylpyridine, results in partial decomposition. This de-rivatization, however, is useful for the enantiomeric resolution of the acid hydrolysates by capillary zone electrophoresis by applying host-guest complexation with crown ethers.11" 22 ... 

Acrylonitrile Allyl acrylate Allyl methacrylate n-Butyl acrylate n-Butyl methacrylate Isobutyl methacrylate Divinyl benzene 2-Choroethyl methacrylate Ethyl acrylate /i-Ethoxyethyl methacrylate 2-Ethylhexyl methacrylate Ethyl methacrylate Methyl methacrylate Methylisopropenylketone Methyl vinyl ketone N-Vinyl pyrrolidone Styrene Vinylpyridine Acrylonitrile Allyl acrylate Allyl methacrylate... 

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. 

The experiments were performed for the samples of neutral PAA gel, into which cations of poly(4-vinylpyridine) quaternized by ethyl bromide were incorporated. The degree of quaternization was 90%. The solvent was the mixture of water with ethanol. The degree of swelling of the networks was characterized by the parameter N/0 and <1>N is the volume fractions of the polymer in the gel at the preparation condition and after swelling in the mixture, respectively. 

Better yields may be obtained from vinylpyridines and alkyl propiolates, as can be seen from the conversion of 36 to the cycl[3,2,2]-azine (lw).41 Reaction of a-(bismethylthio)methylene-2-pyridineaceto-nitrile and ethyl bromoacetate using triethylamine afforded the indolizine derivative (37). Dimethyl l-carbamoyl-2-methylthiocycl-[3,2,2]azine-3,4-dicarboxylate (Iz) was synthesized by allowing dimethyl acetylenedicarboxylate to react with indolizine derivative 38, which was obtained by decarboxylation of 37 using sulfuric acid in presence of palladium-on-charcoal as catalyst [Eq. (6)].42... 

The fact that allyltributyltin and styrene which are electroneutral were successfully added to PCTFE led us to the question "Can electron-rich or electron-poor trapping agents be used ". The electron-rich agents that we examined were ethyl ethynyl ether and ethyl vinyl ether. On the side of the electron-poor alkenes, eight were investigated ethyl acrylate, methyl methacrylate, methyl vinyl ketone, acrylonitrile, methacrylonitrile, vinyl bromide, chloromethyl styrene, and 4-vinylpyridine. The details of each reaction are summarized. 

Hybrid organic-inorganic polymer-polymer composites were prepared by blending with poly(A-vinylpyrrolidone) (PVPr), poly(4-vinylpyridine) (PVPy) and poly(ethyl oxazoline) (PEOx). It was found that the properties of these hybrids depended strongly on the preparation conditions.14... 

Thomas, T. J. et al., Amer. Inst. Aero. Astron. J., 1976, 14, 1334—1335 Ignition temperatures were determined by DTA for the perchlorate salts of ethyl-amine, isopropylamine, 4-ethylpyridine, poly(ethyleneimine), poly(propyleneimine), and poly(2- or 4-vinylpyridine). In contrast to the low ignition temperatures (175— 200°C) of the polymeric salts, mixtures of the polymeric bases with ammonium perchlorate decompose only above 300°C. 

A large number of macromolecules possess a pronounced amphiphilicity in every repeat unit. Typical examples are synthetic polymers like poly(l-vinylimidazole), poly(JV-isopropylacrylamide), poly(2-ethyl acrylic acid), poly(styrene sulfonate), poly(4-vinylpyridine), methylcellulose, etc. Some of them are shown in Fig. 23. In each repeat unit of such polymers there are hydrophilic (polar) and hydrophobic (nonpolar) atomic groups, which have different affinity to water or other polar solvents. Also, many of the important biopolymers (proteins, polysaccharides, phospholipids) are typical amphiphiles. Moreover, among the synthetic polymers, polyamphiphiles are very close to biological macromolecules in nature and behavior. In principle, they may provide useful analogs of proteins and are important for modeling some fundamental properties and sophisticated functions of biopolymers such as protein folding and enzymatic activity. 

Coelectrolysis of azo cpompounds and AN or ethyl acrylate yields 155 and 156, respectively. With 9-benzylidenefluorene and acrylonitrile a biscyanoethyl compound 157 was the major product 431 Further mixed coupling products have been obtained with 2-vinylpyridine and dibutyl maleate 429 or methyl-vinylsulfone and N,N-diethylcinnamic acid amide 430 ... 

The different situations of the block copolyampholyte as a function of pH are depicted in Scheme. 1. The same order of deprotonation was observed in copolymers of poly(methacrylic acid) and poly(2-(diethylamino)ethyl methacrylate) [70, 71, 72, 75-77]. In copolymers of poly(methacrylic acid) [78] and poly(2/4-vinylpyridine), on the other hand, deprotonation of the pyridine hydrochloride takes place prior to deprotonation of the carboxyl [79-83] because in comparison to carboxylic functionalities amine hydrochlorides are the weaker acids and vinylpyridinium hydrochlorides the stronger ones. Thus, in the latter systems an isoelectric point (iep) is not observable, while in the first case polyzwitterions are formed which possess the highest amount of charges at that pH resulting in a polyelectrolyte complex (PEC). In the second case polymers with a minimal net charge built the PEC which is stabilized by hydrophobic interactions often accompanied by hydrogen bonding [79, 84-88]. 

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