Ethyl acrylate, reaction with

A P NMR study of stoichiometric reactions using the di-primary phosphine H2PCH2CH2CH2PH2 provided more information on the reaction mechanism (Scheme 5-12, Eq. 2). Norbornene was displaced from Pt(diphosphine)(norbornene) by ethyl acrylate. Reaction with the diphosphinopropane was very fast this gave the hydrophosphination product, which, remarkably, did not bind Pt to give Pt(diphos-phine), instead, Pt(diphosphine)(norbornene) was observed [12]. 

When lithium aluminum hydride was applied, besides reduction of the C-4—N-5 double bond, the ester group was converted to a hydroxymethyl group. S By reaction with dry formic acid under reflux conditions, the pyrroloquinazoline-2-carboxylates 63 yielded the 6-formyl-5,6-dihydro derivatives 65. S The formyl group was transformed into a methyl group by diborane. S The NH group of the dihydro derivatives 64 was acylated by ethyl chloroformate. Reaction with ethyl acrylate and acrylonitrile involved a Michael addition.The ethoxycarbonyl moiety in position 2 and on the side chain in position 6 was hydrolyzed to a carboxylic group by the action of potassium hydroxide in aqueous methanol and was reduced to a hydroxymethyl group by lithium aluminum hydride in ether. 

The diastereoselectivity inherent to the Diels-Alder reaction can be seen in most of the examples in preceding reactions. The reaction is not, however, enantioselective since there is no facial control for intermolecular reactions (some facial control is available for intramolecular reactions). The ortho rule, the endo rule (secondary orbital interactions), and steric interactions provide some orientational control but facial control is also required for enantioselectivity. When ethyl acrylate reacts with 2-methyl-1,3-pentadiene, it can approach from the bottom as in 247A or from the top as in 247B. Clearly, the two products (248A and 248B) are mirror images and enantiomers. This lack of facial selectivity leads to racemic mixtures in all Diels-Alder cyclizations discussed to this point. 

Fig. 1. Variation of the monomer conversion in the emulsion copolymeiization of methyl methacrylate (MMA) and ethyl acrylate (EA) with reaction time [13], Recipe ISO g water, 20 g MMA, 80 g EA, 2.5 g Tween 40, 2.5 g Spolapon AOS, 60°C. [ NH )2S20g] = 2.92x10 moldm ...

Combining the recommended rate coefficient for reaction with OH radicals with a daytime average [OH] = 2.5 x 10 molecule cm gives an estimate of about 7 h for the daytime atmospheric lifetime of ethyl acrylate. As with alkenes (Calvert et al., 2000) and methacrylates (Blanco et al., 2006), the reaction of OH with ethyl acrylate is believed to proceed via addition to the double bond followed by decomposition of the resulting alkoxy radical. The major oxidation products are CH2O and HC(0)C(0)0C2Hs (ethyl glyoxylate). 

Reaction of 2-aminothiazole with ethyl acrylate yields 5.6-dihydro-7H-thiazolo[3,2a]pyrimidin-7-one (116) (Scheme 78) (169). 

Acetylene-Based Routes. Walter Reppe, the father of modem acetylene chemistry, discovered the reaction of nickel carbonyl with acetylene and water or alcohols to give acryUc acid or esters (75,76). This discovery led to several processes which have been in commercial use. The original Reppe reaction requires a stoichiometric ratio of nickel carbonyl to acetylene. The Rohm and Haas modified or semicatalytic process provides 60—80% of the carbon monoxide from a separate carbon monoxide feed and the remainder from nickel carbonyl (77—78). The reactions for the synthesis of ethyl acrylate are... 

The stoichiometric and the catalytic reactions occur simultaneously, but the catalytic reaction predominates. The process is started with stoichiometric amounts, but afterward, carbon monoxide, acetylene, and excess alcohol give most of the acrylate ester by the catalytic reaction. The nickel chloride is recovered and recycled to the nickel carbonyl synthesis step. The main by-product is ethyl propionate, which is difficult to separate from ethyl acrylate. However, by proper control of the feeds and reaction conditions, it is possible to keep the ethyl propionate content below 1%. Even so, this is significantly higher than the propionate content of the esters from the propylene oxidation route. 

Polymerization processes are characterized by extremes. Industrial products are mixtures with molecular weights of lO" to 10. In a particular polymerization of styrene the viscosity increased by a fac tor of lO " as conversion went from 0 to 60 percent. The adiabatic reaction temperature for complete polymerization of ethylene is 1,800 K (3,240 R). Heat transfer coefficients in stirred tanks with high viscosities can be as low as 25 W/(m °C) (16.2 Btu/[h fH °F]). Reaction times for butadiene-styrene rubbers are 8 to 12 h polyethylene molecules continue to grow lor 30 min whereas ethyl acrylate in 20% emulsion reacts in less than 1 min, so monomer must be added gradually to keep the temperature within hmits. Initiators of the chain reactions have concentration of 10" g mol/L so they are highly sensitive to poisons and impurities. 

By copolymerising with a small amount of second monomer which acts as an obstruction to the unzipping reaction, in the event of this being allowed to start. On the industrial scale methyl methacrylate is sometimes copolymerised with a small amount of ethyl acrylate, and formaldehyde copolymerised with ethylene oxide or 1,3-dioxolane for this very reason. 

The reaction of enamines with perfluoro olefins has also been reported (62). Dienamines have been reported to react with ethyl acrylate at C2 to give the alkylated a,j8-unsaturated ketone derivative. Thus the dienamine (44) gave 71 in 50 % yield on reaction with ethyl acrylate in dioxane for 40 hr (63). 

The reaction of methyl or ethyl acrylate with the enamine of an alicyclic ketone results in simple alkylation when the temperature is allowed to rise uncontrolled in the reaction mixture (7,34,35). If the reaction mixture is kept below 30°C, however, a mixture of the simple alkylated and cyclobutane (from 1,2 cycloaddition) products are obtained (34). Upon distillation of this mixture only starting material and simple alkylated product is obtained because of the instability of the cyclobutane adduct. 

The Diels-Alder reactions of the methyl or ethyl ester of benzenesulfonylindole-2-acrylic acid with several l-alkoxycarbonyl-l,2-dihydropyridines are reported and only a single stereoisomer was obtained, as in the case of l-methoxy(ethoxy)-carbonyl-1,2-dihydropyridines. However, when the Diels-Alder reaction of 17 was carried out with 8g[R = (CHsjsC], a mixture of two stereoisomers 18gand25were obtained in a 1 1 ratio (65% total yield). The bulky rerr-butyl group creates sufficient steric interference with the indole ring to cause the loss of stereochemistry ... 

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