From Trichloroacetic Acid

COCCI3 Preparation by reaction of trichloroacetonitrile on hydro- I quinone (Hoesch reaction) (40%) [4619]. 

T)-ichloro-l-[4-hydroxy-2-methyl-5-(l-methylethyl)phenyl]ethanone 

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Trichloroacetanilide has been prepared from hexachloroacetone and aniline, from trichloroacetyl chloride and aniline, by the action of aniline magnesium iodide on ethyl trichloroacetate, by heating N-phenyltrichloroacetimidyl chloride with dilute methanol, and from trichloroacetic acid and aniline in the presence of phosphorus oxychloride. ... 

The cationic complex [CpFe(CO)2(THF)]BF4 (23) can also catalyze the proton reduction from trichloroacetic acid by formation of Fe-hydride species and may be considered as a bioinspired model of hydrogenases Fe-H Complexes in Catalysis ) [44]. This catalyst shows a low overvoltage (350 mV) for H2 evolution, but it is inactivated by dimerization to [CpFe(CO)2l2-... 

Fung, J.F., Sengelmann, R.D., KenneaUy, C.Z. Chemical injury to the eye from trichloroacetic acid. Dermatol Surg 28, 609-610 (2002)... 

In addition to the usual adenine nucleotides (such as adenosine 5-phosphate, adenosine 5-pyrophosphate, and adenosine 5-triphosphoric acid) present in bacterial extracts, several adenine nucleotides of uncertain structure have been reported. These substances, termed adenylyl peptides have been isolated from trichloroacetic acid extracts of Staphylococcus aureus ... 

Two major metabolites were isolated by paper chromatography (from trichloroacetic acid extracts of the cells) and were identified as 8-azaguano-sine 5-phosphate and 8-azaguanosine, respectively. The two compounds were present in the ratio of 4 1. The structure of the 8-azaguanosine 5-phosphate was indicated by chromatographic and electrophoretic comparison of it with (a) the 5-nucleotide prepared by the action of snake venom on the bacterial ribonucleic acid containing 8-azaguanine, and (b) the 3-nucleotide prepared by alkaline hydrolysis. 

Another method is the iodometric procedure described by the reviewer (G6, G7), where dissolved mucin was precipitated with 1.5 volumes of acetone at 40°G from trichloroacetic acid filtrate of the gastric juice. Mucin, in the precipitate, was quantitated by iodometric titration with the use of a standardization curve of electrodialyzed mucin solution and methylene blue as indicator. The mucin values of gastric juice determined by this method were 20-210 mg%, those of saliva 50-300 mg %. The method was subsequently used by many investigators, yielding satisfactory results (K6, K20, M25, M52, T33, W20, W21) it was considered to yield accurate results (Przylecki, cited in K20) with 6% error (Labby et al, cited in T33). 

Dichloroacetic acid has been prepared by the chlorination of acetic or chloroacetic acid, by hydrolysis of pentachloro-ethane, from trichloroacetic acid by electrolytic reduction or the action of copper, and by the action of alkali cyanides on chloral hydrate. The method described here is essentially that of Delepine. ... 

Analogous decarboxylations, sometimes in the presence of Ca(OD)2, have been used for preparation of labeled aromatic hydrocarbons from the corresponding carboxylic acids,76 e.g.9 [D6]benzene from mellitic acid,77 deuteriochlo-roform from trichloroacetic acid,78 and [6-DJuracil from orotic acid.24... 

Rathore, H. S., Kumari, K., and Agrawal, M. (1985). Quantitative separation of citric acid from trichloroacetic acid on plates coated with calcium sulfate containing zinc oxide. J. Liq. Chromatogr. 8 1299-1317. 

Another example of the use of ion-exchange membranes in electrosynthesis is cathodic dehalogenation. Dichloroacetic acid has been obtained with almost quantitative current yields from trichloroacetic acid by elimination of chlorine at controlled potential [21]. The overall reaction which takes place in the electrolyzer can be written as follows ... 

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. 

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). 

Lynestrenol is the des-3-oxo derivative of norethindrone (28). It has been prepared through a similar synthetic pathway as aHylestrenol (37) (52), ie, addition of potassium acetyUde, rather than aHyl magnesium bromide, affords lynestrenol (73). Lynestrenol is also available from norethindrone (28). Reduction of the 3-keto group is accompHshed by treating norethindrone (28) with sodium borohydride in the presence of trifluoro- or trichloroacetic acid... 

The pixyl ether is prepared from the xanthenyl chloride in 68-87% yield. This group has been used extensively in the protection of the 5 -OH of nucleosides it is readily cleaved by acidic hydrolysis (80% AcOH, 20°, 8-15 min, 100% yield, or 3% trichloroacetic acid). It can be cleaved under neutral conditions with ZnBrj, thus reducing the extent of the often troublesome depurination of A -6-benzyloxy-adenine residues during deprotection. Conditions which remove the pixyl group also partially cleave the THP group (t,/2 for THP at 2 -OH of ribonucleoside = 560 s in 3% Cl2CHC02H/CH2Cl2). ... 

Triethylammonium trichloroacetate [4113-06-8] M 263.6. Equimolar solns of triethylamine and trichloroacetic acid in -hexane were mixed at 10°. The solid so obtained was recrystd from CHCl3/ benzene. 

H. Reaction with Formic and Trichloroacetic Acids Enamines derived from aldehydes have been treated with formic acid under the conditions of the Leuckart-Wallach reaction 141) to give saturated tertiary amines 142). The enamine (98) reacts vigorously with formic acid at room temperature to give N-isobutyl morpholine (204). 

A similar sequence of reactions has been shown to take place with the dienamine derived from isophorone and morpholine (77). Reaction of this enamine with trichloroacetic acid gave a trichloromethyl derivative which was not isolated but which undergoes rearrangement and hydrolysis with base to give the diene acid (210). 

The reaction of iminium salts such as 66 with salts of trichloroacetic acid has been shown to yield amides such as 84 on hydrolysis 126). It was suggested that the reaction proceeds by addition of dichlorocarbene to give an aziridinium intermediate (85), which was opened by trichloroacetate followed by hydrolysis to give the observed products 126). The observed products from the reaction can be accounted for by formation of CCI3,... 

Similarly, a-trichloromethylamines (522) were obtained by decomposition of trichloroacetic acid in morpholine enamines, but an amide ester was formed from sodium trichloroacetate and the imonium salt of pyrrolidino-cyclohexene (523). The product is presumably derived from opening of an intermediate dichloroaziridinium salt. 

The addition of various Kolbe radicals generated from acetic acid, monochloro-acetic acid, trichloroacetic acid, oxalic acid, methyl adipate and methyl glutarate to acceptors such as ethylene, propylene, fluoroolefins and dimethyl maleate is reported in ref. [213]. Also the influence of reaction conditions (current density, olefin-type, olefin concentration) on the product yield and product ratios is individually discussed therein. The mechanism of the addition to ethylene is deduced from the results of adsorption and rotating ring disc studies. The findings demonstrate that the Kolbe radicals react in the surface layer with adsorbed ethylene [229]. In the oxidation of acetate in the presence of 1-octene at platinum and graphite anodes, products that originate from intermediate radicals and cations are observed [230]. 

Trichloroacetic Acid (TCA) causes precipitation of proteins and coagulative necrosis of epidermal cells [4]. The extent of damage is indeed concentration dependent. Concentrations range from 10 to 50%. Superficial TCA peeling is induced by concentrations of 10-30% whereas higher concentrations cause medium depth or deep peeling. The combination of salicylic acid followed by TCA 10-15% induces superficial wounding. 

Ethanol formulations of salicylic acid (20 and 30%) are used for combination peeling (see salicylic acid section). Trichloroacetic acid is prepared as an aqueous solution, since ethanol solutions do not penetrate the skin. It is prepared by mixing the appropriate concentration of crystals with up to 100 cc of distilled water. Ten and fifteen percent TCA is prepared by mixing 10 or 15 g of crystals in up to 100 cc of total volume, respectively. Aqueous solutions of TCA remain stable for up to 6 months unless contaminated. Other methods have been used to formulate TCA peeling solutions however, the weight/volume methods appear to be the most reliable formulation [5]. Premixed TCA solutions are available from a variety of medical... 

Geranyl chloride can be prepared from geraniol by the careful use of triphenylphosphine in carbon tetrachloride. Tris(dimethylamino)phosphine reacts with carbon tetrachloride to form the complex (42) which can be used to form the enol esters (43) from acid anhydrides. Similarly, aldehydes form the alkenes (44), and esters or amides of trichloroacetic acid are converted to glycidic esters. ... 

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