Ethyl acetic ester

The ozonolysis reaction, followed by reductive workup with sulfur dioxide, as described in Part A of the present procedure, illustrates a general method which has been developed for the preparation of acetals. Application of the procedure is illustrated by conversion of the following olefins in alcoholic solution to the corresponding acetals (1) l-chloro-4-(o-nitrophenyl)-2-butene to o-nitrophenylacetaldehyde dimethyl acetal in 84% yield (2) l,4-dibromo-2-butene tobromoacetaldehyde dimethyl acetal in 67% yield (3) 3-butenoic acid to malonaldehydic acid diethyl acetal ethyl ester in 61% yield (4) cyclopentadiene to malonaldehyde bis(diethyl acetal) in 48% yield and (5)... 

Scheme 2.2 Enantioselective kinetic resolution of cis/ttoris (IR,5R)-bicyclo[3.2.0]hept-6-ylidene-acetate ethyl ester, 1, catalyzed by immobilized lipase from Candida antarctica (Novozyme 435). The reaction is run in a pH-stat at pH 8.0 and...

Despite the fact that solvent effects on enzyme enantioselectivity appear to resist our efforts to rationalize their outcome using commonly accepted solvent descriptors, the effects are certainly there. An impressive example is provided in a report on the successful resolution of ds/trans-( 1 R,5 R)-bicyclo[3.2.0]hept-6-ylidene-acetate ethyl esters, intermediates in the synthesis of GABA (y-aminobutyric acid) analogs, by the Pfizer Bio transformations and Global R D groups (Scheme 2.2) [136]. From a screening protocol, CaLB was identified as a reactive catalyst for the hydrolysis of the racemic mixture of / //-os lor enantiomers with approximately equal activity for the ds- and tmns-isomers and a rather modest (E = 2.7) preference for the /Z-(lR,5R)-enantiomers. Application of medium engineering resulted in a phenomenal increase in the enantioselectivity (addition of 40% acetone, E > 200), while the ds- and trans-isomers were still converted at an almost equal rate. 

Preparation 199.—Ethyl Acetate [Ethyl ester of ethan acid], CH3.COOC2H5. C4H802. 88. 

The sodium (18 gms.), in small pieces, or in the form of wire, is added gradually, and a few drops of acetic ethyl ester may be added to accelerate the reaction. 

Phenyl hydrazine (10 gms.) is added to acoto-acetic ethyl ester (12-5 gms.) and well shaken much heat is evolved, and when the reaction is over the oily product is separated from tlio water formed, and heated on the water-batli till a sample poured into water becomes solid (2 hours). Tlio whole is poured while still warm into ether, the white precipitate... 

Diethyl oxalate or ethyl oxalyi chloride. a-Oxydiethyl-acetic ethyl ester. Pranidand, Annalen, 1863, 126, 109 Prankland and Duppa, Anmleti, 1865, 135, 29 Henry, Ber., 1872, 5, 950. 

Capronic and isobutyl-acetic ethyl esters--Ethyl alco-... 

As a general guide, however, it may be noted that the following have fairly easily recognisable odours methyl and ethyl formate methyl and ethyl acetate (apples) methyl and ethyl benzoate methyl salicylate (oil of winter-green) and ethyl salicylate methyl and ethyl cinnamate. (It is however usually impracticable to distinguish by odour alone between the methyl and ethyl esters of a particular acid.) Methyl and ethyl o. alate, and methyl and ethyl phthalate are almost odourless. Succinic and tartaric esters have faint odours. 

The addition of active methylene compounds (ethyl malonate, ethyl aoeto-acetate, ethyl plienylacetate, nltromethane, acrylonitrile, etc.) to the aP-double bond of a conjugated unsaturated ketone, ester or nitrile In the presence of a basic catalyst (sodium ethoxide, piperidine, diethylamiiie, etc.) is known as the Michael reaction or Michael addition. The reaction may be illustrated by the addition of ethyl malonate to ethyl fumarate in the presence of sodium ethoxide hydrolysis and decarboxylation of the addendum (ethyl propane-1 1 2 3-tetracarboxylate) yields trlcarballylic acid ... 

Esters. re-Butyl acetate Ethyl acetate Ethyl benzoate. 

Dichloroacetic acid is produced in the laboratory by the reaction of chloral hydrate [302-17-0] with sodium cyanide (31). It has been manufactured by the chlorination of acetic and chloroacetic acids (32), reduction of trichloroacetic acid (33), hydrolysis of pentachloroethane [76-01-7] (34), and hydrolysis of dichloroacetyl chloride. Due to similar boiling points, the separation of dichloroacetic acid from chloroacetic acid is not practical by conventional distillation. However, this separation has been accompHshed by the addition of a eotropeforming hydrocarbons such as bromoben2ene (35) or by distillation of the methyl or ethyl ester. 

Analytical results of distilled spidts are expressed either by chemical class or by individual constituent. When these results are expressed by chemical class, the most prevalent constituent within that class is used as the marker, eg, acetic acid for acids, acetaldehyde for aldehydes, and ethyl acetate for esters. Wet chemical methods are employed in the deterrnination of results by chemical class, while more advanced and refined techniques are employed in the deterrnination of individual chemical constituents. 

Since the acetal exists in equiUbtium with the aldehyde, it is possible for the aldehyde to be released when water is added in a mixed drink, changing the balance and giving a burst of freshness to a mixed drink. Ethyl esters of terpene alcohols in citms oils and other botanicals, plus the ethyl esters of fatty and volatile acids, are formed during prolonged exposure to ethyl alcohol. Certain beverage alcohol products that need to contain milk, eggs, or other protein containing materials must be developed carefully and the added flavors must be considered to prevent the precipitation of the protein and separation of the product. 

Esters of medium volatility are capable of removing the water formed by distillation. Examples are propyl, butyl, and amyl formates, ethyl, propyl, butyl, and amyl acetates, and the methyl and ethyl esters of propionic, butyric, and valeric acids. In some cases, ternary azeotropic mixtures of alcohol, ester, and water are formed. This group is capable of further subdivision with ethyl acetate, all of the ester is removed as a vapor mixture with alcohol and part of the water, while the balance of the water accumulates in the system. With butyl acetate, on the other hand, all of the water formed is removed overhead with part of the ester and alcohol, and the balance of the ester accumulates as a high boiler in the system. 

The hydrolysis of ethyl acetate, prepared by the reaction of ethylene with acetic acid under pressure (154), and the hydrolysis of the ethyl ester of chlorosulfonic acid (155) have been considered and found to be of Httie industrial importance. 

Acetanilides, benzoyl-colour couplers in colour photography, 1, 372 Acetanilides, pivaloyl-colour couplers in colour photography, 1, 372 Acetazolamide — see l,3,4-Thiadiazole-2-sulfonamide, 5-acetamido-Acetic acid, acetamidocyano-ethyl ester, 1, 307 Acetic acid, 2-acylphenyl-isochroman-3-one synthesis from, 3, 858 Acetic acid, 3-benzo[6]thiophenyl-biological activity, 4, 912 Acetic acid, l,2-benzoxazol-3-yl-electrophilic substitution, 6, 48... 

Acetic acid, 3-ethoxycarbonyl-l-methyl-2-pyrrolyl-ethyl ester reduction, 4, 287 Acetic acid, 9-hydroxyethoxy-as metabolite of dioxane, 1, 245... 

Acetic acid, 2-hydroxy-2-(2-pyrrolyl)-ethyl ester... 

Me2Sn(SMe)2, BF3-Et20, PhCH3, 0°, 3-24 Ji AcOH, 75-100% yield." An ethyl ester can be hydrolyzed in the presence of an MEC ester with 1 N aqueous NaOH-DMSO (1 1), and MEC esters can be cleaved in the presence of ethyl, benzyl, cinnamyl, and t-butyl esters as well as the acetate, TBDMS and MEM ethers. 

Carbethoxymethylene)triphenylphosphorane, (Ethoxycarbonylmethylene)tri-phenylphosphorane Acetic acid, (triphenylphosphoranylidene)-, ethyl ester (8,9) (1099-45-2)... 

Acetate Esters Methyl acetate Ethyl acetate Propyl acetate Isopropyl acetate Butyl acetate Isobutyl acetate Amyl acetate... 

Enantiomerically pure dipeptide is obtained when the /7-nitrophenyl ester of N-henzoyl-L-leueine is coupled with glycine ethyl ester in ethyl acetate ... 

Esters — These are not very reactive. Only the lowest molecular weight esters have appreciable solubility in water (e.g., ethyl acetate, 8%). Methyl and ethyl esters are more volatile than the corresponding unesterified acids. Most common esters are flammable. Esters are often easily recognizable due to their sweet to pungent odors. 

Chemical Designations - Synonyms Acetic acid, ethyl ester. Acetic ester. Acetic ether. Ethyl ethanoate Chemical Formula CHjCOOCHjCHj... 

---