Dichloroacetic acid methyl ester

The outflow of a sewage pipe continuously adds dissolved dichloroacetic acid methyl ester (dichloromethylacetate, DCMA) to a small river. The mean concentration in the effluent is 400 pg L 1. In the river, DCMA undergoes a base-catalyzed reaction (see Table 13.8). At a water temperature of 15°C, kh is 0.2 h-1 for pH = 7 and 2.0 h 1 for pH = 8. 

DICHLOROACETIC ACID see DELOOO DICHLOROACETIC ACID METHYL ESTER see DEM800... 

Cuprous Oxide 1317-39-1 Dichloroacetic Acid Methyl Ester 116-54-1 Diisobutyl Adipate 141-04-8... 

DICHLOROACETIC ACID, METHYL ESTER (116-54-1) Combustible liquid (flash point 176°F/80°C). Aqueous solution is an acid incompatible with sulfuric acid, alkalis, ammonia, aliphatic amines, alkanolamines, alkylene oxides, amides, epichlorohydrin, organic anhydrides, isocyanates, vinyl acetate. Strong oxidizers may cause fire and explosions. Attacks metals in the presence of moisture. 

Carbonyl Chloride - Dichloroacetic Acid Methyl Ester... 

Much effort towards stereoselective synthesis of 3-deoxy-2-ulosonic acids resulted in the development of several strategies based on the diverse building units. Among them aldol reaction between D-arabinose derivative 50 and methyl dichloroacetate (51) deserves some attention [78] (Scheme 14). The condensation product isolated as oxirane derivative 52 reacted smoothly with Mgk to give the intermediate 53, easily convertible into 3-deoxy-D-ara6mo-2-heptulosonic acid methyl ester 56 in high yield. 

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. 

Derivatization is also useful to detect volatile metabolites. Liu et al. [282] described a specific, rapid, and sensitive in situ derivatization solid-phase microextraction (SPME) method for determination of volatile trichloroethylene (TCE) metabolites, trichloroacetic acid (TCA), dichloroacetic acid (DCA), and trichloroethanol (TCOH), in rat blood. The metabolites were derivatized to their ethyl esters with acidic ethanol, extracted by SPME and then analyzed by gas chromatography/negative chemical ionization mass spectrometry (GC-NCI-MS). After validation, the method was successfully applied to investigate the toxicokinetic behavior of TCE metabolites following an oral dose of TCE. Some of the common derivatization reagents include acetyl chloride and TV-methyl-iV- ft-b u (y Idi methyl si I y I) tro (1 uoroacctam i nc (MTBSTFA) for phenols and aliphatic alcohols and amines, dansyl chloride and diazomethane for phenols, dansyl chloride for amines, acidic ethanol and diazomethane for carboxylic acids, and hydrazine for aldehydes. 

Dichloroacetic acid, often abbreviated DCA, is the chemical compound with formula CHCI2COOH. It is an acid, an analogue of acetic acid in which two of the three hydrogen atoms of the methyl group have been replaced by chlorine atoms. The salts and esters of dichloroacetic acid are called dichloroacetates. Salts of DCA are used as drugs since they inhibit the enzyme pyruvate dehydrogenase kinase. 

Chloroacetate esters are usually made by removing water from a mixture of chloroacetic acid and the corresponding alcohol. Reaction of alcohol with chloroacetyl chloride is an anhydrous process which Hberates HCl. Chloroacetic acid will react with olefins in the presence of a catalyst to yield chloroacetate esters. Dichloroacetic and trichloroacetic acid esters are also known. These esters are usehil in synthesis. They are more reactive than the parent acids. Ethyl chloroacetate can be converted to sodium fluoroacetate by reaction with potassium fluoride (see Fluorine compounds, organic). Both methyl and ethyl chloroacetate are used as agricultural and pharmaceutical intermediates, specialty solvents, flavors, and fragrances. Methyl chloroacetate and P ionone undergo a Dar2ens reaction to form an intermediate in the synthesis of Vitamin A. Reaction of methyl chloroacetate with ammonia produces chloroacetamide [79-07-2] C2H ClNO (53). 

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