Product description
Ethyl pyruvate has its formula be CH3COCOOC2H5. It is also known as 2-oxo-propionic acid ethyl ester. It is as a colorless transparent liquid at room temperature with fresh, sweet floral aroma. It can be applied to the formulation of flavors of apples, citrus, chocolate, etc. It is an extremely important intermediate of organic synthesis with wide applications in pharmaceutical (synthetic drugs of thiophene), pesticides (herbicides of DuPont company, thiophene-class fungicide), food (can be used as a preservative, antiseptic agent, etc.), cosmetics and other industries.
Ethyl Pyruvate has excellent efficacy in inhibiting the formation of tyramine enzyme in the epidermis. Therefore, it is possible to prevent the formation of melanin in the skin and has skin whitening effect. It can also serve as an effective active ingredient for being supplemented into the air freshener, and can effectively clear the ammonia and methyl mercaptan in the air with fresh and clean smells. Ethyl pyruvate also has excellent performance in constituting the heterocyclic compound and is indispensable raw material and intermediate in the synthesis of pesticides. It is widely used for the synthetic fungicides and herbicides. The oxazolone derivative synthesized from ethyl pyruvate is also an excellent fungicide and can effectively inhibit and kill the fungus at a concentration of 5.0 × 10-4.
Pyruvate is the main raw material for the production of tryptophan, phenylalanine, carbohydrate, protein and vitamin B. It is also the raw materials for biologic synthesis of L-dopamine (dopamine can be applied to the treatment of Parkinson's disease) and is the initiator of ethylene polymers as well as the raw material for preparation of grains protective agent. Starting from pyruvate, people are able to synthesize an efficient herbicide. This herbicide has an excellent selectivity with good efficacy in killing weeds such as sedge and green foxtail weeds while is safe to the crops. As feed and food additives, it has good preservative function and is currently used to store feed and wine in small amount. Ethyl pyruvate itself has a special flavor and can be applied to flavors, fragrances, and is also an important raw material for synthetic resins and plastic materials. Pyruvic acid esters can also be used as a special solvent for being applied to electronic materials. For the application of this area, the foreign demand is increasing rapidly.
The above information is edited by the chemicalbook of Dai Xiongfeng.
Limited use
(mg/kg): 50 Beverage; cold 20~150; candy 35; 40 bakery products.
It is limited to an appropriate amount (FDA, §172.515, b2001).
Chemical Properties
Methyl pyruvate is a yellow transparent liquid, [CAS 600-22-6] b.p.134~137 ℃, n20D 1.4040, relative density 1.130, it is soluble in alcohols, ketones and other organic solvents.
Ethyl pyruvate is a yellow transparent liquid with the b. p. being 144 ℃, n20D being 1.4050 and the relative density being 1.060; it is also soluble in organic solvents.
Uses
It can be used in the manufacture of pharmaceutical pindolol and pesticides thiabendazole. At the same time, it is an important intermediate of pharmaceutical and chemical industry. It is widely applied to various kinds of industries including medicine, pesticides, flavors and fragrances, food additives, air fresheners, fine chemicals and other industries. It can be used in the synthesis of cardiovascular drugs like expansion agent; it can also be applied to cosmetic of skin whitening and nutrition and can promote the healing of the wound, prevention and treatment of skin disease characterized by cracking, spalling and squamous metaplasia; it can be used as the high-efficiency active ingredients in the air fresheners and can effectively eliminate the ammonia and methyl mercaptan in the air; because itself has a special flavor, it can be applied to flavors, fragrance; it is also an important raw material for synthetic resins and plastics.
Production method
There are several methods for its preparation.
Gas-phase oxidation of ethyl lactate
Gas-phase oxidation of ethyl lactate is conducted in the presence of a catalyst with MoO3 catalyst exhibiting a higher selectivity than other kinds of metal oxides. In addition, binary oxide catalysts containing molybdenum oxide such as Fe2O3-MoO3 and TeO2-MoO3 also have a high selectivity on synthesis pyruvate ester (temperature 300 ℃, selectivity is higher than 90%), if using SnO2-MoO3 as the catalysts, it can be carried out at a relatively low temperature (for example, 250 ℃). SnO2-MoO3 catalysts can also be used as the catalyst of lactate liquid-phase oxidation with the reaction temperature being 130 ℃ and the reaction time being 3h. The conversion rate of ethyl lactate was 38.4% and the selectivity is 98.9% which produces ethyl pyruvate.
Liquid phase oxidation of ethyl lactate
Ethyl lactate is subject to liquid-phase oxidation in the presence of a small amount of bromine as the catalyst. Use H2O2 as the oxidant for performing the oxidation reaction, for example, 50% H2O2 was stirring added drop wise to a dichloromethane solution of ethyl lactate and the bromine upon sunshine. The reaction temperature is maintained at 25 ℃ and the addition time of H2O2 is controlled at about 1.5 h and the reaction was continued for 3 h after the completion of the dropping. The solution was neutralized with NaHCO3 and washed with Na2SO3 solution; destroy and remove the peroxide ethyl lactate, peroxide and then obtain the ethyl pyruvate through concentration and distillation under reduced pressure.
The oxidation of acrylate
Use H2O2 to oxidize the acrylate to generate pyruvate ester in the presence of Cr or V compound as the catalyst. For example, to make isopropyl acrylate, in the presence of chromium triacetylacetate as the catalyst, add H2O2 with stirring to the acetonitrile solvent; the reaction temperature is maintained at 50 ℃ with 8 h obtaining isopropyl acrylate with the selectivity being 99.1% and the conversion rate being 87.9%. Another example is that, methyl acrylate, in the presence of chromium triacetylacetate or chromic acid, is added of triethylamine for reaction of 20h with the temperature 40 ℃, the selectivity 72% and the conversion rate of 82% to give methyl pyruvate.
In addition, methylglyoxal and methanol can be subject to gas phase reaction in the presence of nickel phosphate catalyst to obtain methyl pyruvate.
Chemical Properties
clear pale yellow liquid
Chemical Properties
Ethyl pyruvate has a vegetable, caramel odor.
Occurrence
Reported found in Parmesan cheese, cognac, grape wines, cocoa and mushrooms.
Uses
Ethyl pyruvate is used as a flavoring agent in food and anti-inflammatory agent for the treatment of critical inflammatory conditions. It is used in the treatment of critical illnesses such as severe sepsis, acute respiratory distress syndrome, burn injury, acute pancreatitis and stroke. It plays an important role in cardiac function after coronary ischemia and reperfusion.
Uses
Ethyl pyruvate can undergo asymmetric Henry reaction with nitromethane to form α-hydroxy β-nitro esters. It can be used as the model compound for α-ketoesters to study the mechanism of enantioselective hydrogenation reactions.
Uses
Ethyl pyruvate (EP) has demonstrated neuroprotective effects against acute brain injury through its anti-inflammatory action.
Definition
ChEBI: Ethyl pyruvate is an oxo carboxylic acid.
Preparation
By direct esterification of pyruvic acid with absolute ethyl alcohol at the boil and subsequent vacuum distillation; by
esterification via oxidation of vapors of ethyl lactate in the presence of V2O5 at 155°C
Taste threshold values
Taste characteristics at 60 ppm: sweet, rum-like with a fruity ethereal nuance.
General Description
Ethyl pyruvate is a volatile aliphatic ester of the pyruvate metabolite. It is present as a food additive/odor-active component in various food and beverage products. It is also used as an inhibitory odorant to repel the insects from human proximity.
Purification Methods
Shake the ester with 10mL portions of saturated aqueous CaCl2 solution (removes ethyl acetate) and the organic layer is removed by centrifugation, decantation and filtration, and is distilled under reduced pressure. Purification of small quantities is carried out via the bisulfite adduct: the ester (2.2mL) is shaken with saturated NaHSO3 (3.6mL), chilled in a freezing mixture when crystals separate rapidly (particularly if seeded). After 5minutes EtOH (10mL) is added and the crystals are filtered off, washed with EtOH and Et2O and dried. Yield ca 3g of bisulfite adduct. Then treat the adduct (16g) with saturated aqueous MgSO4 (32mL) and 40% formaldehyde (5mL) and shake, whereby the ester separates as an oil which is extracted with Et2O. The extract is dried (MgSO4), filtered, evaporated and the residue is distilled (b 56o/20mm), and then redistilled (b 147.5o/750mm) to give 5.5g of pure ester. [Cornforth Org Synth Coll Vol IV 467 1963, Beilstein 3 IV 1513.]
