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Ethyl acrylate is an with the formula CH2CHCO2CH2CH3. It is the of . It is a colourless liquid with a characteristic acrid odor. It is mainly produced for paints, textiles, and non-woven fibers. It is also a in the synthesis of various pharmaceutical intermediates.


Production
Ethyl acrylate is produced by acid-catalysed esterification of acrylic acid, which in turn is produced by oxidation of . It may also be prepared from , and ethanol by a Reppe reaction. Commercial preparations contain a polymerization inhibitor such as , , or hydroquinone ethyl ether.


Reactions and uses

Precursor to polymers and other monomers
Ethyl acrylate is used in the production of polymers including resins, plastics, rubber, and denture material. Ethyl acrylate Hazardous Substance Fact Sheet, New Jersey Department of Health and Senior Services

Ethyl acrylate is a reactant for homologous alkyl acrylates (acrylic esters) by transesterification with higher alcohols through acidic or basic catalysis. In that way speciality acrylates are made accessible, e.g. 2-ethylhexyl acrylate (from 2-ethylhexanol) used for pressure-sensitive adhesives, cyclohexyl acrylate (from ) used for automotive clear lacquers, 2-hydroxyethyl acrylate (from ) which is crosslinkable with to form gels used with long-chain acrylates (from C18+ alcohols) as comonomer for for reduction of the solidification point of and 2-dimethylaminoethyl acrylate (from dimethylaminoethanol) for the preparation of flocculants for sewage clarification and paper production.

As a reactive monomer, ethyl acrylate is used in homopolymers and copolymers with e.g. , and its salts, and esters, , , , , , vinylidene chloride, , butadiene and unsaturated polyesters. Copolymers of acrylic acid ethyl ester with ethene (EPA/ethylene-ethyl acrylate copolymers) are suitable as adhesives and polymer additives, just like ethene vinyl acetate copolymers. Copolymers with acrylic acid increase the cleaning effect of , copolymers with methacrylic acid are used as gastric juices tablet covers (Eudragit).

The large number of possible comonomer units and their combination in copolymers and terpolymers with ethyl acrylate allows the realization of different properties of the acrylate copolymers in a variety of applications in paints and adhesives, paper, textile and leather together with cosmetic and pharmaceutical products.


As Michael acceptor and HX acceptor
Ethyl acrylate reacts with amines catalyzed by Lewis acids in a to β-alanine derivatives in high yields:

The nucleophilic addition at ethyl acrylate as an α,β-unsaturated carbonyl compound is a frequent strategy in the synthesis of pharmaceutical intermediates. Examples are the or the (obsolete by now) Pharmazeutische Wirkstoffe: Synthesen, Patente, Anwendungen; von A. Kleemann u. J. Engel; 2., neubearb. u. erw. Aufl.; Stuttgart, New York; Thieme; 1982, or more recent therapeutics such as the COPD agent or the .D. Lednicer, The Organic Chemistry of Drug Synthesis, Volume 7, J. Wiley & Sons, 2008,

Ethyl 3-bromopropionate is prepared by of ethyl acrylate.


Dienophile
With , ethyl acrylate reacts as a good dienophile in Diels–Alder reactions e.g. with buta-1,3-diene in a 4+2 reaction to give a cyclohexene carboxylic acid ester in a high yield.K.P.C. Vollhardt, N.E. Schore, Organische Chemie, 5. Aufl., Wiley-VCH, 2012,


Natural occurrence
Ethyl acrylate is also used as a flavoring agent. It has been found as a volatile component in and and is a secondary component in vanilla flavor obtained from heat extraction of vanilla in amounts of up to 1 ppm. In such high concentrations it negatively affects the extracted aroma. Sensory-Directed Flavor Analysis, Ray Marsili edit., CRC Press, Taylor & Francis Group, Boca Raton, 2007,


Safety
The International Agency for Research on Cancer stated, "Overall evaluation, ethyl acrylate is possibly carcinogenic to humans (Group 2B)." IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Volume 71, International Agency for Research on Cancer (1999) The United States Environmental Protection Agency (EPA) states, "Human studies on occupational exposure to ethyl acrylate... have suggested a relationship between exposure to the chemical(s) and colorectal cancer, but the evidence is conflicting and inconclusive. In a study by the National Toxicology Program (NTP), increased incidence of squamous cell papillomas and carcinomas of the forestomach were observed in rats and mice exposed via gavage (experimentally placing the chemical in the stomach). However, the NTP recently determined that these data were not relevant to human carcinogenicity since humans do not have a forestomach, and removed ethyl acrylate from its list of carcinogens." EPA Technology Transfer Network, Air Toxics Web Site , United States Environmental Protection Agency (accessed 2008) However, ethyl acrylate also increased the incidence of thyroid follicular cell adenoma in male mice, and thyroid follicular cell adenoma or carcinoma (combined) in male rats exposed through inhalation.

It is possibly carcinogenic and it is toxic in large doses, with an LD50 (rats, oral) of 1020 mg/kg. As of October 2018, the FDA withdrew authorization for its use as a synthetic flavoring substance in food.

One favorable safety aspect is that ethyl acrylate has good warning properties; the odor threshold is much lower than the concentration required to create an atmosphere immediately dangerous to life and health. Reports of the exact levels vary somewhat, but, for example, the EPA reports an odor threshold of 0.0012 parts per million (ppm), but the EPA's lowest level of health concern, the Acute Exposure Guideline Level-1 (AEGL-1) is 8.3 ppm, which is almost 7000 times the odor threshold.

However, as a possible carconigen, NIOSH maintains "that there is no safe level of exposure to a carcinogen. Reduction of worker exposure to chemical carcinogens as much as possible through elimination or substitution and engineering controls is the primary way to prevent occupational cancer."


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