Ethyl 2,2-dichloroacetate

Ethyl dichloroacetate/535-75-97 M 157.0, b 131.0-131.5°/401mm, d 1.28, n 1.438. Shaken with aqueous 3% NaHC03 to remove free acid, washed with distd water, dried for 3 days with CaSOa and distd under reduced pressure. 

Figure 1.2. H NMR spectrum of ethyl dichloroacetate (CDCI3, 25 °C, 80 MHz). The proton of the CHCh group is less shielded (more strongly deshielded) in comparison with the protons of the CH2 and CHj residues...

The //NMR spectrum of ethyl dichloroacetate (Fig. 1.2), as an example, displays a triplet for the CHs group (two vicinal H), a quartet for the OCH2 group (three vicinal H) and a singlet for the CHCh fragment (no vicinal H for eoupling). 

Acetylamino-1 -(4-methylmercaptophenyl)-1,3-propanediol Hydrogen chloride Ethyl dichloroacetate Peracetic acid... 

A mixture of 1.1 g of 2-amino-1-(4-methylmercaptophenyl)-1,3-propanediol, obtained as described above and 1.6 ml of ethyl dichloroacetate was heated on a steam bath for three hours. The resulting viscous yellow oil was dissolved in 25 ml of ethylene chloride and filtered hot with charcoal, and the filtrate was allowed to cool to about 25°C. From the filtrate there separated 0,92 g of tiny white leaflets which were collected on a filter. Recrystallization of this product, which was a dextro-rotary form of 2-dichloroacetylamino-1-(4-methylmercapto-phenyl)-1,3-propanediol from nitroethane yielded the pure product, which melted at 111.6°C to 112.6°C,... 

METHYL-, HYDROCHLORIDE, 31, 37 Ethyl benzolacetate, 32, 85 O-Ethylcaprolactim, 31, 73 Ethyl chloroacetate, 30, 7 Ethyl /9-chloroisocrotonate, 32, 78 Ethyl cyanoacetate, 32, 45 Ethyl dichloroacetate, 32, 47 Ethylene, 32, 100 Ethylene, tetraphenyl-, 31,104... 

Ethyl diazoacetate, 36, 25 Ethyl dichloroacetate, 32, 47 Ethyl diethoxyacetate, 35, 59 Ethyl enanthylsuccinate, 34, 51 Ethylene, 32, 100 37, 65 Ethylene, 1,1-dichloro-2,2-dipi.uoro-,... 

Imidazole will function as a general base in the hydrolysis of acyl-activated esters such as ethyl dichloroacetate Qencks and Carriuolo, 1961) and esters where the p/STg-value of the leaving group is 2-3 units lower than that of ethanol and methanol such as... 

The acid chloride was obtained from the Eastman Kodak Company and was used without prior treatment. The submitters report that dichloroacetic acid or ethyl dichloroacetate may be substituted for dichloroacetyl chloride but that the reaction appears to be smoother with the acid chloride. 

Ethyl acetate Diazide (Bistriazo-essigs aure-ttthylester in Ger), (Ng CH.CO.OCsHj mw 170.13, N 49.4, OB to C02 -84-7, colorless, odorless, liquid, bp 70—72° (about 2 torr), sp gria 1.222, sp gr24-91.220, n 9 1.4640. It was prepd in 1908 by refluxing ethyl dichloroacetate with NaN3 (Ref 3). It tended to expl in contact with coned sulfuric acid. It was considered too dangerous to explore further Refs 1) Beil 2, 230 Sc (101) 2) J.C. Philip,... 

The slow step of this process is often the initial nucleophilic displacement, and although the alkaline hydrolysis reaction (Y = HO ) is unique in that only a single displacement is involved, the step concerned is the same as the ratedetermining step for the reaction with many other nucleophiles. Kinetically, therefore, the reactions are comparable. A second important type of catalysis by nucleophilic reagents does not involve direct attack by the nucleophile on the ester. For example, the hydrolysis of ethyl dichloroacetate is catalyzed by aniline, and no anilide is produced in the reaction186, viz. 

General base catalysis of ester hydrolysis by nucleophiles other than amines and oxyanions has not been characterized, though it would be expected to be closely similar to the reaction involving these bases. Cyanide ion, for example, would be expected to catalyze the hydrolysis of ethyl esters with activated acyl groups, such as ethyl dichloroacetate, by this mechanism. 

Heating a mixture of 6,7,8,9-tetrahydro-ll//-pyrido[2,l-b]quinazolin-ll-one (7) and acetyl and benzoyl chlorides, acetic anhydride, and vinyl acetate under reflux gave 6-condensation products (123), whereas reactions with ethyl chloroacetate, ethyl dichloroacetate, and chloral hydrate afforded 6-substituted products (124) (86MI7). 6,7,8,9-Tetrahydro-ll//-pyrido[2,l-b]quinazolin-l 1-one (7) and acetic anhydride, heated under reflux for 36 h, gave compound 123 (X = OAc, R = Me or X = Me, R = OAc, 18%) and its 6-acetyl derivative (124, R = COMe) in 31% yield (87JHC175 91JHC2071). 

Figure 2.5 The Br0nsted plot for the general-base catalysis of the hydrolysis of ethyl dichloroacetate. The logarithms of the second-order constants obtained from the plot of Figure 2.4 are plotted against the pAT s of the conjugate acid of the catalytic base. The slope is the /3 value. Note that the points for amine bases ( ) fall on the same line as those for oxyanion bases (O), showing that the catalysis depends primarily on the basic strength of the base and not on its chemical nature.

Fiqure 2.4 Determination of the rate constants for the general-base catalysis of the hydrolysis of ethyl dichloroacetate. The first-order rate constants for the hydrolysis are plotted against various concentrations of the base. The slope of the linear plot is the second-order rate constant (k2). The intercept at zero buffer concentration is the "spontaneous hydrolysis rate constant for the particular pH. A plot of the spontaneous rate constants against pH gives the rate constants for the H+ and OH" catalysis. It is seen that pyridine is a more effective catalyst than the weaker base acetate ion. [From W. P. Jencks and J. Carriuolo, J. Am. Chem. Soc. 83,1743 (1961).]... 

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