Acrylic acid ethyl ester, preparation

Preparation of 2-hydroxy-3-pyridin-3-y 1-acrylic acid ethyl ester... 

Higher acrylates may be prepared by the use of the appropriate alcohol in the above processes or by esterification of free acrylic acid. However, ester interchange is usually a more economical method because of the ready availability of ethyl acrylate. A mixture of ethyl acrylate (in excess) and the alcohol is heated in the presence of sulphuric acid,p-toluenesulphonic acid or a titanate catalyst and a polymerization inhibitor. The reaction is taken to high degrees of conversion by distilling off the ethyl acrylate-ethanol azeotrope as it is formed. 

CHi=CMeCOOH. Colourless prisms m.p. 15-16 C, b.p. 160-5 C. Manufactured by treating propanone cyanohydrin with dilute sulphuric acid. Polymerizes when distilled or when heated with hydrochloric acid under pressure, see acrylic acid polymers. Used in the preparation of synthetic acrylate resins the methyl and ethyl esters form important glass-like polymers. 

Various alkylating agents are used for the preparation of pyridazinyl alkyl sulfides. Methyl and ethyl iodides, dimethyl and diethyl sulfate, a-halo acids and esters, /3-halo acids and their derivatives, a-halo ketones, benzyl halides and substituted benzyl halides and other alkyl and heteroarylmethyl halides are most commonly used for this purpose. Another method is the addition of pyridazinethiones and pyridazinethiols to unsaturated compounds, such as 2,3(4//)-dihydropyran or 2,3(4//)-dihydrothiopyran, and to compounds with activated double bonds, such as acrylonitrile, acrylates and quinones. 

The tetracyclic /3-carboline derivatives 452-454 have been prepared as sleep disorder therapeutics. The synthesis (Scheme 100) involves the reaction between the enamino ester 451 and acrylic acid derivatives, activated in certain cases with ethyl chloroformate <1997TL8475>. 

Thiodipropionic acid esters have been prepared by the addition of hydrogen sulfide to the corresponding acrylic esters in the presence of basic catalysts with or without solvents. The ethyl ester has also been prepared by the treatment of ethyl jS-chloropropionate with sodium sulfide. ... 

Esters of allyl alcohol, e.g., diallyl phthalate, are used as bifunctional polymerization monomers and can be prepared by simple esterification of phthalic anhydride with allyl alcohol. Several acrylic esters, such as ethyl or methyl acrylates, are also widely used and can be made from acrylic acid and the appropriate alcohol. The esters are more volatile than the corresponding acids. 

Under the heading acrylic elastomer the plastic literature has included a broad spectrum of carboxy-modified rubbers that have as a minor portion of the comonomers acrylic acid and/or its derivatives. However, in more recent usage the term acrylic elastomer is used to designate these rubbery products that contain a predominant amount of an acrylic ester, such as ethyl acrylate or butyl acrylate in the polymer chain. Fluoroacrylate elastomers are based on plastics prepared from the acrylic acid ester-dihydroperfluoro alcohols. 

The polymeric products can be made to vary widely in physical properties through controlled variation in the ratios of monomers employed in their preparation, cross-linking, and control of molecular weight. They share common qualities of high resistance to chemical and environmental attack, excellent clarity, and attractive strength properties (see Acrylic ESTER POLYMERS). In addition to acrylic acid itself, methyl, ethyl, butyl, isobutyl, and 2-ethylhexyl acrylates are manufactured on a large scale and are available in better than 98—99% purity (4). They usually contain 10—200 ppm of kydroquinone monomethyl ether as polymerization inhibitor. 

The procedure for the elimination of HBr from the dibromo ester is a modification of the method of Lawton and co-workers for sui generis generation of the methyl or ethyl ester during a reaction. Methyl a-(bromomethyl)acrylate has also been prepared by bromination of methyl methacrylate in 700°C steam and by dehydrohalogenation with sodium acetate in acetic acid. Ethyl a-(bromomethyl)acrylate has been prepared by dehydrohalogenation with the monosodium salt of ethylene glycoP and ethyl diisopropylamine." The latter reaction was reported by Ohler et al. with no experimental details for the elimination reaction. The use of triethylamine as reported in this procedure appears to be the most efficient and convenient method for dehydrobromination to these acrylate esters. 

Direct, acid catalyzed esterification of acrylic acid is the main route for the manufacture of higher alkyl esters. The most important higher alkyl acrylate is 2-ethylhexyl acrylate prepared from the available oxo alcohol 2-ethyl-1-hexanol (see Alcohols, higher aliphatic). The most common catalysts are sulfuric or toluenesulfonic acid and sulfonic acid functional cation-exchange resins. Solvents are used as entraining agents for the removal of water of reaction. The product is washed with base to remove unreacted acrylic acid and catalyst and then purified by distillation. The esters are obtained in 80—90% yield and in excellent purity. 

For example, methyl and ethyl acrylate can be prepared by adding bromine to acrylic acid, esterifying the dibromide, and boiling the resulting 2,3-dibromopropionic ester with pieces of zinc in alcohol.74... 

The properties of acrylic ester polymers depend largely on the type of alcohol from which the acrylic acid ester is prepared [26]. Solubility in oils and hydrocarbons increases as the length of the side chain increases. The lowest member of the series, poly(methyl acrylate), has poor low-temperature properties and is water sensitive. It is therefore restricted to such applications as textile sizes and leather finishes. Poly(ethyl acrylate) is used in fiber modifications and in coatings and poly(butyl acrylate) and poly(2-ethylhexyl acrylate) are used in the formulation of paints and adhesives. 

The usage of acrylic esters as building blocks for polymers of industrial importance began in earnest with the experimentation of Otto Rohm (1). The first recorded preparation of the basic building block for acrylic ester polymers, acrylic acid, took place in 1843 this synthesis relied on the air oxidation of acrolein (2,3). The first acrylic acid derivatives to be made were methyl acrylate and ethyl acrylate. Although these two monomers were synthesized in 1873, their utility in the polymer area was not discovered until 1880 when Kahlbaum polymerized methyl acrylate and tested its thermal stability. To his surprise, the polymerized methyl acrylate did not depolymerize at temperatures up to 320°C (4). Despite this finding of incredibly high thermal stability, the industrial production of acrylic ester polymers did not take place for almost another 50 years. 

Most water and waste water treatment applications use polymers that are cationic in character that are predominantly prepared by copolymerisation of acrylamide with varying proportions of amino derivatives of acrylic acid or methacrylic acid esters. The most commonly used monomers in this class are dimethyl amino ethyl (meth) acrylate quater-nised with methyl chloride or other quaternising agents. Polymerisation is conducted under acidic conditions to prevent base catalysed hydrolysis of the ester linkage. Copolymers with allyl monomers, such as DADMAC are also manufactured however the molecular weight of these polymers is limited by the relative stability of the intermediate radical. 

Various esters of acrylic acid are commercially available but ethyl acrylate is the most widely used. The esters may, of course, be obtained by the reaction of acrylic acid and the appropriate alcohol but most generally the esters are prepared by processes which do not involve the isolation of free acrylic acid. Thus in the standard method for the preparation of ethyl acrylate, ethylene cyanohydrin is dehydrated, hydrolyzed and esterified in one operation by heating with concentrated sulphuric acid in the presence of ethanol at about 140 C (cf., acrylic acid, Section 6.2.1). The overall reaction is ... 

The acrylic rubbers are based on acrylic ester polymers of which a very large number have been prepared. The acrylic ester monomers (II) may be considered, in structural terms, to be derivatives of acrylic acid (I), with ethyl acrylate (III) being a typical member of this family ... 

The Wittig-Horner olefination can also be achieved in aqueous heterogeneous media (Rambaud et ai, 1984). Thus ( )-vinylphosphonates were prepared in good yields from aldehydes and tetraethylmethylene diphospho-nate in boiling water. Ethyl (diethylphosphono)acetates are alkylated in the same conditions providing in one pot a-acrylic acid esters (Kirschleger and Queignec, 1986) ... 

Palladium is a useful catalyst in several reactions which lead to keto-esters. p-Keto-esters react with allylic carbonates, with catalysis by palladium, in a decarboxylative allylation reaction. y-Keto-esters are prepared, in reasonable yield, by the palladium-catalysed regioselective oxidation of Py-unsaturated esters. y-Keto-esters are obtained in good yield by the palladium-catalysed Reformatsky reaction of ethyl bromoacetate and acid chlorides. Derivatives of y-ketopimelic acid are formed by the rhodium-carbonyl-catalysed reaction of derivatives of acrylic acid with carbon monoxide. A mild method for the conversion of propiolic esters into P-keto-esters via thiol addition has been reported (Scheme 63) it has been used in a formal synthesis of ( )-thienamycin. 

Starting from nucleic acid bases, the carboxyethyl derivatives of the nucleic acid bases were prepared by a Michael type addition reaction of ethyl acrylate followed by hydrolysis. The carboxyethyl derivatives of nucleic acid bases were reacted with ( )-a-amino T-butyrolactone hydrobromide to give v-hutyrolactone derivatives of nucleic acid bases. For the coupling reactions, pentachlorophenyl ester derivatives were used with imidazole as a catalyst.22... 

Various esters of acrylic add are commercially available but methyl, ethyl and butyl acrylates are the most widely used. These esters are obtained by esterification of acrylic acid. The appropriate alcohol, acrylic acid and a catalyst (generally sulphuric add) are fed into a reactor at about 80°C and the ester separated by distillation. Higher acrylates are conveniently prepared by ester interchange. 

The preparation of esters of tertiary alcohols is accomplished by the reaction of an olefin with a carboxylic acid. For example, isobutylene condenses with malonic acid to give 58-60% of di-/cr/-butyl malonate, with monoethyl maleate to give 53-58% of ethyl tert-butyl malonate, and with acrylic acid to give 47% tert- >vAy acrylate. 

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