Ethyl propionate, hydrolysis

The formation of acyloins (a-hydroxyketones of the general formula RCH(OH)COR, where R is an aliphatic residue) proceeds best by reaction between finely-divided sodium (2 atoms) and esters of aliphatic acids (1 mol) in anhydrous ether or in anhydrous benzene with exclusion of oxygen salts of enediols are produced, which are converted by hydrolysis into acyloins. The yield of acetoin from ethyl acetate is low (ca. 23 per cent, in ether) owing to the accompanying acetoacetic ester condensation the latter reaction is favoured when the ester is used as the solvent. Ethyl propionate and ethyl ji-butyrate give yields of 52 per cent, of propionoin and 72 per cent, of butyroin respectively in ether. 

Table 5 Specific Rate Constant kr x 10 min ) of the Resin Catalyzed Hydrolysis of Ethyl Propionate in Aqueous Solvents at 25°C...

Xiancheng Z, Xiaonan C, Ziming Q, Qian W. The alkaline hydrolysis of ethyl acetate and ethyl propionate in single and mixed micellar solutions. J Disper Sci Technol 1996 17(3) 339-348. 

Enantioselective D-A reactions of chiral esters and amides of acrylic acid can be achieved using achiral Lewis acid such as TiCU. After the reaction, enantiomeric pure carboxylic acid can be recovered on hydrolysis. For example, the reaction of acrylic acid with cyclopentadiene using chiral a-hydroxy ethyl propionate 95a as chiral auxiliary in the presence of TiCU gives only one enantiomeric product in large excess (93 %) [82]. The chiral auxiliary 95a reacts with dienophile to produce a chiral ester 95, which participates in the reaction with cyclopentadiene. 

Propionic acid [79-09-4] M 74.1, b 141 , d 0.992, n 1.3865, n25 1.3843, pK 5-6.8 (Ho scale, aq H2SO4), pK2 4.88. Dried with Na2S04 or by fractional distn, then redistd after refluxing with a few crystals of KMn04. An alternative purification uses the conversion to the ethyl ester, fractional distn and hydrolysis. [Bradbury J Am Chem Soc 74 2709 1952.] Propionic acid can also be heated for 0.5h with an amount of benzoic anhydride equivalent to the amount of water present (in the presence of Cr03 as catalyst), followed by fractional distn. [Cham and Israel 7 C/iem 5oc 96 I960.]... 

C. Hydrolysis of Ethyl a, fi-Dicyano- -phenyl Propionate — The product thus obtained is hydrolyzed by boiling under a reflux condenser for four hours with 80 cc. of concentrated hydrochloric acid (sp. gr. 1.19). The substance goes into solution and this clear solution, on cooling, deposits phenylsuccinic acid in small crystals which are nearly colorless. These are filtered off, washed with cold water and dried. The yield of product melting at 164-166° is 17.6-18.4 g. (91-95 per cent of the theoretical amount based on the weight of ester used) (Notes 1 and 2). 

The metabolism of carfentrazone-ethyl in animals and plants is similar. The major plant metabolites are carfentrazone-chloropropionic acid (C-CI-PAc), 3-desmethylcarfentrazone-chloropropionic acid (DM-C-CI-PAc), and 3-hydroxymethylcarfentrazone-chloropropionic acid (HM-C-CI-PAc). The major animal metabolites are carfentrazone-chloropropionic acid (C-CI-PAc) and carfentrazone-propionic acid (C-PAc). The tolerance expression for livestock and plant commodities is carfentrazone-ethyl plus the ester hydrolysis product, C-CI-PAc. 

Reactions of 2,3-dioxo-l,2,3,5,6,7-hexahydropyrido[l,2,3-carboxylic acids and the homologous acetic and propionic acids, prepared by basic hydrolysis of the corresponding ester, with amines, 28% NH4OH, and hydroxylamine derivatives in the presence of l-ethyl-3-[3-(dimethylamino)propyl]carbodiimide and hydroxybenztria-zole <1995BML1527>, 1995BML1533>, and in the presence of NEt3 and A, A -bis(2-oxo-3-oxazolidinyl)phosphinic... 

Hydrolysis, of ethyl a-(isopropylid-eneaminooxy)propionate, 48,121 of halogenated aromatic compounds in the presence of copper and cuprous oxide, 48, 96 of fl-iso valerol ac tam-N-su 1 fony 1 chloride to give /S-isovalerolactam, 46,51... 

The presence of the propionamide fragment in the stmcture of the anti-inflammatory agent broperamole (125-1) is reminiscent of the heterocycle-based NSAID propionic acids. The activity of this agent may trace back to the acid that would result on hydrolysis of the amide. Tetrazoles are virtually always prepared by reaction of a nitrile with hydrazoic acid or, more commonly, sodium azide in the presence of acid in a reaction very analogous to a 1,3-dipolar cycloaddition. A more recent (and safer) version of the reaction noted later (see losartan, 77-4) uses tributyltin azide. In the case at hand, reaction of the anion of mefa-bromobenzonitrile (125-1) with sodium azide and an acid affords the tetrazole (125-2). Condensation of the anion from that intermediate with ethyl acrylate leads to the product from Michael addition saponiflcation gives the corresponding carboxylic acid (125-3). This is then converted to the acid chloride reaction with piperidine affords broperamole (125-4) [136]. 

Carbonation of benzo[6]thienylmethylmagnesium chlorides usually gives only a low yield of the required acetic acid (Section VI,D,4).485,517,526,528 a- Hydroxy - a-(3-benzo[6]thienyl)propionic acid (306) is formed by hydrolysis of the product of the reaction between 3-benzo[6]thienylmagnesium bromide and ethyl pyruvate.207... 

The above directions are based upon the methods of Hoogewerff and Van Doip, as modified by Holm and by Hale and Honan. -Alanine has also been prepared by the action of h3q)obromite upon succinimide and hydrolysis of the resulting /3-ureidopropionic acid by the action of ammonia upon /3-iodo-propionic acid by the hydrolysis of methyl carbomethoxy-/8-aminopropionate, obtained by the action of sodiiun methoxide on succinbromimide by the reduction of 3-nitrosopropionic acid by heating ethyl acrylate with alcoholic ammonia from succinyl-glycine ester by the azide synthesis and by the action of liquid ammonia upon methyl acrylate. ... 

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