Methyl vinyl pyridine

Polyester fibers are composed of linear chains of polyethylene terephthalate (PET), which produces benzene, benzoic acid, biphenyl, and vinyl terephthalate on pyrolysis. Acrylic fibers comprise chains made up of acrylonitrile units, usually copolymerized with less than 15% by weight of other monomers, e.g., methyl acrylate, methyl methacrylate, or vinylpyrrolidone. Thermolysis results in the formation of acrylonitrile monomer, dimers, and trimers with a small amount of the copolymer or its pyrolysis product. In this case, the acrylic is Orion 28, which contains methyl vinyl pyridine as comonomer. Residual dimethyl formamide solvent from the manufacturing process is also found in the pyrolysis products. Cotton, which is almost pure cellulose, comprises chains of glucose units. The pyrolysis products of cellulose, identified by GC/MS, include carbonyl compounds, acids, methyl esters, furans, pyrans, anhydrosugars, and hydrocarbons. The major pyrolysis products are levoglucosan (1,6-anhydro-B-D-glucopyranose) and substituted furans. 

FIGURE 8.11 Pyrograms of (a) polyester, (b) acrylic, and (c) cotton fibers. 1 = benzene, 2 = vinyl benzoate, 3 = benzoic acid, 4 = biphenyl, 5 = acrylonitrile, 6 = dimethyl formamide, 7 = methyl vinyl pyridine, 8 = acrylonitrile dimers, 9 = acrylonitrile trimers, 10 = 2-furalde-hyde, 11 = dihydromethylfuranone, 12 = levoglucopyranose. 

Flax, hemp, jute, ramie, etc. methyl vinyl pyridine... 

Pyridyl)hydrazine (Aldrich), 4-acetylpyridine (Acros), N,N,N -trimethylethylenediamine (Aldrich), methylrhenium trioxide (Aldrich), InQj (Aldrich), Cu(N0j)2-3H20 (Merck), Ni(N03)2-6Il20 (Merck), Yb(OTf)3(Fluka), Sc(OTf)3 (Fluka), 2-(aminomethyl)pyridine (Acros), benzylideneacetone (Aldrich), and chalcone (Aldrich) were of the highest purity available. Borane dimethyl sulfide (2M solution in THE) was obtained from Aldrich. Methyl vinyl ketone was distilled prior to use. Cyclopentadiene was prepared from its dimer immediately before use. (R)-l-acetyl-5-isopropoxy-3-pyrrolin-2-one (4.15) has been kindly provided by Prof H. Hiemstra (University of Amsterdam). 

The other main source of various pyridopyridazines from pyridines are the [4 + 2] cycloaddition reactions, already mentioned (Section 2.15.8.3), between vinylpyridines and azodicarboxylic esters (79T2027, 79KGS639) or triazolidinediones e.g. 78KGS651). 2-Vinyl-pyridines gave reduced pyrido[3,2-c]pyridazines (370), 4-vinylpyridines gave [3,4-c] analogues, whilst 2-methyl-5-vinylpyridine furnishes a mixture of the [2,3-c] and [4,3-c] compounds. Yields are low, however, and these remain curiosities for practical synthetic purposes. 

NOTE - Petrochemical plants also generate significant amounts of solid wastes and sludges, some of which may be considered hazardous because of the presence of toxic organics and heavy metals. Spent caustic and other hazardous wastes may be generated in significant quantities examples are distillation residues associated with units handling acetaldehyde, acetonitrile, benzyl chloride, carbon tetrachloride, cumene, phthallic anhydride, nitrobenzene, methyl ethyl pyridine, toluene diisocyanate, trichloroethane, trichloroethylene, perchloro-ethylene, aniline, chlorobenzenes, dimethyl hydrazine, ethylene dibromide, toluenediamine, epichlorohydrin, ethyl chloride, ethylene dichloride, and vinyl chloride. 

For example, the Diels-Alder reaction of A-benzyl-3-carboxamido-1,6-dihydro-pyridine (14a) andlV-benzyl-3-cyano-l,6-dihydropyridine (14b) with methyl vinyl ketone yielded isoquinuclidines 15a and 15b, respectively, which can be converted into ibogamine alkaloid (16). 

The aziridine aldehyde 56 undergoes a facile Baylis-Hillman reaction with methyl or ethyl acrylate, acrylonitrile, methyl vinyl ketone, and vinyl sulfone [60]. The adducts 57 were obtained as mixtures of syn- and anfz-diastereomers. The synthetic utility of the Baylis-Hillman adducts was also investigated. With acetic anhydride in pyridine an SN2 -type substitution of the initially formed allylic acetate by an acetoxy group takes place to give product 58. Nucleophilic reactions of this product with, e. g., morpholine, thiol/Et3N, or sodium azide in DMSO resulted in an apparent displacement of the acetoxy group. Tentatively, this result may be explained by invoking the initial formation of an ionic intermediate 59, which is then followed by the reaction with the nucleophile as shown in Scheme 43. 

Peracetic acid, formed in situ from acetic acid and hydrogen peroxide in acid aqueous solution, was found to initiate graft copolymerization of vinyl monomers, e.g. methyl methacrylate and 4-vinyl pyridine, onto wood and cellulosic fibers at a good rate (1-3 h time) at 60°C2. The initiati on reaction is not specific for grafting and considerable amounts of homopolymer is formed. 

Radiation Induced Reactions. Graft polymers have been prepared from poly(vinyl alcohol) by the irradiation of the polymer-monomer system and some other methods. The grafted side chains reported include acrylamide, acrylic acid, acrylonitrile, ethyl acrylate, ethylene, ethyl methacrylate, methyl methacrylate, styrene, vinyl acetate, vinyl chloride, vinyl pyridine and vinyl pyrrolidone (13). Poly(vinyl alcohols) with grafted methyl methacrylate and sometimes methyl acrylate have been studied as membranes for hemodialysis (14). Graft polymers consisting of 50% poly(vinyl alcohol), 25% poly(vinyl acetate) and 25% grafted ethylene oxide units can be used to prepare capsule cases for drugs which do not require any additional plasticizers (15). 

Condensation (FeCl, ZnClj, HCl) of these amine salts with methyl vinyl ketone produced 4-methylthleno[2,3-/>]thieno[2,3-h]pyridine and 4-methylthieno[3,2-6]thieno[2,3-6]pyridine, respectively , while acetylacetone (ZnClj) afforded the 2,4-dimethyl derivatives. 5-Ethyl-2-formylthieno[2,3-Z>]thiophene (211) and nitromethane by the Knoevenagel method gave 2-/3-nitrovinyI-5-ethylthienol2,3-6]-thiophene (212) (73%) reduction (LAH) of 212 led to the 2-/3-amino-ethyl analog (213) lEq. (69)]. 

In contrast to these vapour-phase reactions, it has been reported that ketones and aqueous ammonia (or ammonium acetate) in an autoclave give less complex mixtures of pyridines. Crotonaldehyde gives 5-ethyl-2-methylpyridine (570) in up to 59% yield, methyl vinyl ketone gives 2,3,4-trimethylpyridine (571) rather than 2,3,6-trimethylpyridine 1,3,3-trimethoxybutane has been used in place of methyl vinyl ketone (49JA2629). In some cases reverse aldol reactions occur (for example with benzalacetophenone) giving unwanted products. A similar reverse aldol is responsible for the production of triarylpyridines (572) when benzalacetophenones are treated with formamide and ammonium formate (73JA4891). 

Mixing of the crystalline ingredients of oxidant, fuel elastomer binder (butadiene-2-methyl-5 vinyl-pyridine copolymer plasticized with the formal of diethylene glycol monobutyl ether) 26% by vol is done in a sigma blade mixer. The completed mix is blocked in a hydraulic press to form a chge suitable for extrusion. The extruded strand is cut into grain blanks which are cured at... 

To 0.2 mole of an olefin dissolved in 30 ml of glacial acetic acid is added 19.5 gm (0.3 mole) of sodium azide in 75 ml of water. The addition to acrolein and jf -nitrostyrene underwent rapid addition, requiring cooling with an ice-salt bath and slow addition of the sodium azide. Addition to methyl acrylate, acrylic acid, and acrylonitrile required 1-3 days at room temperature, a-vinyl pyridine and mesityl oxide required heating for 24 hr on a steam bath. Other olefins underwent no reaction even after 7 days of heating and were recovered unchanged. 

The main point to note is that the use of an additional ligand such as adiponitrile, vinyl acetate or methyl vinyl ketone is useless similar yields were obtained. Considering the fact that the presence of an additional ligand did not raise the reaction yields and could have negative effects if the optimal amount is not present in the reaction mixture, it was decided to work without any ligand. The use of dimethylformamide or dimethylacetamide instead of acetonitrile did not lead to organozinc species formation when these solvents were used without addition of pyridine. 

A comparison of the stereochemistry of the 2-vinyl pyridine addition to [2a] with that of methylation addition is particularly instructive. Table 2 shows the stereochemistry of formation of [7a] as a function of counterion size and coordination. 

The size and coordination of the cation as well as the position of the nitrogen atom in both ultimate and penultimate pyridine groups are key parameters in the stereoselectivity of methylation and 2-vinyl pyridine addition. 

In all cases, three methyl absorptions could be observed at 6 = 0.28, 0.68, and 1.29 ppm in addition to the methylene absorptions at 2.30 and 2.44 ppm. The results (Table 4) show that the differences in stereochemistry between the various counterions are not nearly as important as observed for the oligomerization of 2-vinyl pyridine. 

PDADMA = poly(dialIyldimethylammonium chloride), PSS = poly(styrenesulfonic acid), PAMPS = poly(2-acrylamido-2-methyl-l-propane sulfonic acid), and PFPVP = 4-vinyl-trideca-fluoro-octyl pyridi-nium iodide-co-4-vinyl pyridine. 

An unusual step in a synthesis of (+)-muscopyridine [146] is the methyl addition on an enolate. It appears that the oxygenated carbon still retains sufficient acceptor character by virtue of its relationship to the pyridine nitrogen (cf. reactivity of 2-vinyl-pyridine). 

Gold nanoparticles can also be stabilized using polymers that do not have specific functional groups through physisorption. Among the possible stabilizers, the polymers used most often to stabilize Au NPs are the water soluble polymers poly(N-vinylpyrrolidone) (PVP), polyethylene glycol) (PEG), poly(vinyl pyridine), poly(vinyl alcohol) (PVA), poly(vinyl methyl ether) (PVME), and polyelectrolytes such as PAA, chitosan, polyethyleneimine (PEI) or poly(diallyl dimethylammonium) chloride (PDDA) [99]. 

We have considered above the predictions of the general theory of the swelling and collapse of charged networks which contain both positive and negative charges. These predictions were first checked in Ref. [15]. The objects of the investigation were the copolymers of AA with SMA and 2-methyl-5-vinyl-pyridine, quatemized by dimethyl sulfate (MVPQ), crosslinked with BAA. The solvents were mixtures of water with ethanol. 

In the case of the electron poor alkenes, results were more varied. Under all conditions examined, reactions with methyl vinyl ketone, acrylonitrile, methacrylonitrile and 4-vinyl pyridine afforded products with IR spectra equivalent to those obtained without the addition of the alkene (side reaction). In the cases of vinyl bromide and chloromethyl styrene, unreacted PCTFE was recovered unchanged. It is speculated that electron transfer to the alkene proceeded in each case. While the product of vinyl bromide reduction was not observed, perhaps because of volatility, one could isolate poly(chloromethylstyrene) in the latter case. 

Other monomers have been successfully grafted on polyamide under UV light sources. Hence, organic acids as acrylic (72,73), methacrylic (74), ftimaric (73), itaconic (73), and styrene sulfonic in 25% aqueous solution (73). Methyl acrylate and acrylamide in the presence of photosensitizers (74,75) and acrylonitrile (76) are reported as well. Heterocyclic derivatives as vinyl pyridine and vinyl pyrrolidone under UV light using photosensitizers as benzophenone were grafted on Nylon 66 cloth (77). 

Graft copolymers of polyamides using pre-irradiation gamma-rays techniques have been reported for styrene (130), in solution, in the presence of water (40), in alcohols or acetone solution (131), vinyl acetate (130), methacrylic acid in water (132) or methanol solution (129), methyl (133) and ethyl (130) acrylates, 2-ethylhexyl acrylate (55,134), methyl methacrylate (130), in methanol solution (129), 2-dimethylamino ethyl methacrylate quaternary salts (135), acrylamide in aqueous medium (128,136), acrylonitrile (130,137), and 4-vinyl pyridine in aqueous solution (128). 

The literature reports direct grafting by gamma-rays exposure of Nylon fibers or films to the following monomers carbon monoxide (/65), ethylene (157), propylene (157), acetylene (166), butadiene (157.162,163), styrene (158, 161,163,167,168), vinyl chloride (157,163), vinyl fluoride (169-172), vinyl acetate (161,163,173), vinyl propionate (161), vinyl butyrate (161), vinyl crotonate (161), vinyl 2-ethyl hexanoate (161), acrylic add (173,174), methyl acrylate (162, 163), ethyl acrylate (162,163), allyl acrylate (163), methyl methacrylate (28,161, 163,164), butyl methacrylate (161), acrylamide (158), methylol acrylamide (163), acrylonitrile (157,160-163, 167, 175-179), divinyl sulfone (161), vinyl pyridine (167,173), vinyl pyrrolidone (28) and triallyl cyanurate (158). 

Methyl-5-vinyl pyridine (149) 2-Methyl-5-vinyl pyridinium acetate (110) Methylol acrylamide (163)... 

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