Methyl acrylate, addition

As a typical example, the catalytic reaction of iodobenzene with methyl acrylate to afford methyl cinnamate (18) is explained by the sequences illustrated for the oxidative addition, insertion, and /3-elimination reactions. 

Copolymerization can be carried out with styrene, acetonitrile, vinyl chloride, methyl acrylate, vinylpyridines, 2-vinylfurans, and so forth. The addition of 2-substituted thiazoles to different dienes or mixtures of dienes with other vinyl compounds often increases the rate of polymeriza tion and improves the tensile strength and the rate of cure of the final polymers. This allows vulcanization at lower temperature, or with reduced amounts of accelerators and vulcanizing agents. 

Some details of the chain-initiation step have been elucidated. With an oxygen radical-initiator such as the /-butoxyl radical, both double bond addition and hydrogen abstraction are observed. Hydrogen abstraction is observed at the ester alkyl group of methyl acrylate. Double bond addition occurs in both a head-to-head and a head-to-tail manner (80). 

The versatility of this reaction is extended to a variety of aldehydes. The bisphenol derived from 2,6-di-/ f2 -butylphenol and furfural, (25) where R = furfuryl (13), is also used as an antioxidant. The utility of the 3,5-di-/ f2 -butyl-4-hydroxyben2yl moiety is evident in stabili2ets of all types (14), and its effectiveness has spurred investigations of derivatives of hindered alkylphenols to achieve better stahi1i2ing quaUties. Another example is the Michael addition of 2,6-di-/ f2 -butyl phenol to methyl acrylate. This reaction is carried out under basic conditions and yields methyl... 

A large number of hindered phenoHc antioxidants are based on the Michael addition of 2,6-di-/ f2 -butylphenol and methyl acrylate under basic catalysis to yield the hydrocinnamate which is a basic building block used in the production of octadecyl 3-(3,5-di-/ f2 butyl-4-hydroxyphenyl)propionate, [2082-79-3], tetrakis(methylene-3(3,5-di-/ f2 butyl-4-hydroxylphenyl)propionate)methane [6683-19-8], and many others (63,64). These hindered phenolic antioxidants are the most widely used primary stabilizers in the world and are used in polyolefins, synthetic and natural mbber, styrenics, vinyl polymers, and engineering resins. 2,6-Di-/ f2 -butylphenol is converted to a methylene isocyanate which is trimerized to a triazine derivative... 

Michael-Type Additions. Michael additions are generally used to prepare methyl 3-mercaptopropionate (eq. 10) and mercaptopropionitrile (eq. 11) by the reaction of methyl acrylate or acrylonitrile and hydrogen sulfide using a basic catalyst. This reaction proceeds as shown ... 

Polymer Composition. Ethylene—acrylic elastomer terpolymers ate manufactured by the addition copolymerization of ethylene [74-85-1] and methyl acrylate [96-33-3] in the presence of a small amount of an alkenoic acid to provide sites for cross-linking with diamines (4). 

The process yields a random, completely soluble polymer that shows no evidence of crystallinity of the polyethylene type down to —60°C. The polymer backbone is fully saturated, making it highly resistant to ozone attack even in the absence of antiozonant additives. The fluid resistance and low temperature properties of ethylene—acryUc elastomers are largely a function of the methyl acrylate to ethylene ratio. At higher methyl acrylate levels, the increased polarity augments resistance to hydrocarbon oils. However, the decreased chain mobiUty associated with this change results in less fiexibihty at low temperatures. 

A new family of peroxide-cured dipolymers was introduced in 1991. The peroxide cure provides copolymers that cure faster and exhibit good compression set properties without a postcure. The removal of the cure-site has also made the polymer less susceptible to attack from amine-based additives. By varying the methyl acrylate level in the dipolymer, two offerings in this family have been synthesized, VAMAC D and its more oil-resistant... 

The Michael-type addition of maleic hydrazide and other pyridazinones to activated alkenes, such as methyl acrylate, acrylonitrile, methyl vinyl ketone and other a,/3-unsatu-rated carbonyl compounds, results in the formation of mono-lV-substituted products. 

The methanol-methyl acrylate azeotrope contains about 45% methyl acrylate, which can be recovered by washing out the methanol with a large volume of water or brine the acrylate is purified by, drying and distilling. An inhibitor, such as hydro-quinone, should always be added to any acrylic ester before attempting to distil it, and, unless it is stored in a refrigerator, the distilled ester should not be kept more than a few hours without the addition of a small amount (0.1-1.0%) of an inhibitor. 

An example of this improvement in toughness can be demonstrated by the addition of Vamac B-124, an ethylene/methyl acrylate copolymer from DuPont, to ethyl cyanoacrylate [24-26]. Three model instant adhesive formulations, a control without any polymeric additive (A), a formulation with poly(methyl methacrylate) (PMMA) (B), and a formulation with Vamac B-124 (C), are shown in Table 4. The formulation with PMMA, a thermoplastic which is added to modify viscosity, was included to determine if the addition of any polymer, not only rubbers, could improve the toughness properties of an alkyl cyanoacrylate instant adhesive. To demonstrate an improvement in toughness, the three formulations were tested for impact strength, 180° peel strength, and lapshear adhesive strength on steel specimens, before and after thermal exposure at 121°C. 

It is interesting to see that the addition of methyl acrylate to the pyrrolidine enamine derivative of 2-methylcyelohexanone in benzene gave equal amounts of 2-methyl-2-carbomethoxyethyl and 2-methyl-6-earbomethoxy-ethylcyclohexanone even though the less substituted double-bond isomer predominates in the starting enamine (199,200,237). In contrast, the methylation of the same enamine mixture led only to 2,6-dimethyleyclo-... 

Michael addition reaction of 1-hydroxytryptamines to Q ,/3-unsaturated carbonyl compounds is worthy of note (99H2815). Addition of Ab-acetyl- 1-hydroxy-tryptamine (39) to methyl acrylate and methyl crotonate in the presence of... 

The ratio of the two diastereomeric products 190 and 191 was found to depend on the reaction temperature and reaction time. The addition of acrolein or methyl vinyl ketone proceeded smoothly, but in the case of methylacrylate or acrylonitrile the reaction did not proceed under the same conditions (EtsN THF 30°C). An accompanying AMI calculation of these Q ,/3-unsaturated compounds [LUMOs for acrolein, -0.13877 for methyl vinyl ketone, -0.06805 (s-trans) for methyl acrylate, -0.01413 (s-tmns) for acrylonitrile, 0.04971] suggested the low reactivity of methyl acrylate and acrylonitrile toward the Michael reaction (99H1321). 

Both experimental [7] and theoretical [8] investigations have shown that the anti complexes of acrolein and boranes are the most stable and the transition states were located only for these four anti complexes. The most stable transition-state structure was calculated (RHF/3-21G) to be NC, while XT is the least stable of the four located. The activation energy has been calculated to be 21.6 kcal mol for the catalyzed reaction, which is substantially above the experimental value of 10.4 1.9 kcal mol for the AlCl3-catalyzed addition of methyl acrylate to butadiene [4a]. The transition-state structure NC is shown in Fig. 8.5. 

Thus, condensation of isoniazide with acetone at the basic nitrogen gives the corresponding Shiff base (8). Catalytic reduction affords the antidepressant, iproniazid (9). Addition of the same basic nitrogen to methyl acrylate by Michael condensation leads to the 3-amino ester (10). This is converted to the amide, nialamide (11), on heating with benzylamine. 

Concerning the reaction of ACPC with diols, the frequent use of poly(ethylene glycol) has to be mentioned [20-24]. Ueda et al. ([22-24]) reacted preformed poly(ethylene glycol) (Mn between 6 x 10 to 2 x 10 ) with ACPC. In this case, unlike the reaction of ACPA with diols vide ante), no additional condensation agent was needed. The ethylene glycol-based thermally labile polymers were used to produce blocks with poly(vinyl chloride) [22], poly(styrene) [23], poly(methyl acrylate), poly(vinyl acetate), and poly(acrylonitrile) [24]. 

Giese and Kretzschmar7j found the rate of addition of hexenyl radicals to methyl acrylate increased 2-fold between aqueous tetrahydrofuran and aqueous ethanol, Salikhov and Fischer74 reported that the rate constant for /-butyl radical addition to acrylonitrile increased 3.6-fold between tetradecane and acetonitrile. Bednarek et al75 found that the relative reactivity of S vs MMA towards phenyl radicals was ca 20% greater in ketone solvents than it was in aromatic solvents. 

Kochi (1956a, 1956b) and Dickerman et al. (1958, 1959) studied the kinetics of the Meerwein reaction of arenediazonium salts with acrylonitrile, styrene, and other alkenes, based on initial studies on the Sandmeyer reaction. The reactions were found to be first-order in diazonium ion and in cuprous ion. The relative rates of the addition to four alkenes (acrylonitrile, styrene, methyl acrylate, and methyl methacrylate) vary by a factor of only 1.55 (Dickerman et al., 1959). This result indicates that the aryl radical has a low selectivity. The kinetic data are consistent with the mechanism of Schemes 10-52 to 10-56, 10-58 and 10-59. This mechanism was strongly corroborated by Galli s work on the Sandmeyer reaction more than twenty years later (1981-89). 

In the presence of strong alkali dialkyl phosphites can be added to unsaturated compounds. Thus salts of carboxyethyl- or dicarboxyethylphosphonic acid are obtained by addition of dialkyl phosphites to methyl acrylate [99] in the presence of sodium methylate in methanol. Diethylmaleate similarly gave diethyldiethylphosphonosuccinate [100], according to Eqs. (55) and (56) ... 

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