Trichloracetic acid

Chloral hydrate is obtained by the action of chlorine upon ethyl alcohol. The solid chloral alcoholate is foimed, CClj.CHOH.OCjHj, which, when decomposed with sulphuiic acid, yields chloral, CCI3.COH, a licpiid which combines with water to form the ciystalline hydrate. 

Properties.— It crystallises in prisms, which dissolve easily in water, alcohol, and liquid hydrocarbons. It has a peculiar smell m. p. 57 b. p. 97 5°- It volatilises on evaporating its aqueous solution. 

Reactions.—i. Add a few drops of a solution of chloral hydrate to a little ammonio-silver nitrate solution and waiin. Metallic silver will be deposited. 

Add a little caustic soda to a solution of chloral and warm gently. The heat of the hand is sufficient for the purpose. A smell of chloroform is at once apparent, CCl3.CH(OH)o + NaOH = CHClj +HCO.ONa + HjO. Sodium foimate remains in solution. 

Add a few drops of ammonium sulphide solution and warm gently. A brown colouration 01 precipitate is formed. 

---

In acidic solution, the degradation results in the formation of furfural, furfuryl alcohol, 2-furoic acid, 3-hydroxyfurfural, furoin, 2-methyl-3,8-dihydroxychroman, ethylglyoxal, and several condensation products (36). Many metals, especially copper, cataly2e the oxidation of L-ascorbic acid. Oxalic acid and copper form a chelate complex which prevents the ascorbic acid-copper-complex formation and therefore oxalic acid inhibits effectively the oxidation of L-ascorbic acid. L-Ascorbic acid can also be stabilized with metaphosphoric acid, amino acids, 8-hydroxyquinoline, glycols, sugars, and trichloracetic acid (38). Another catalytic reaction which accounts for loss of L-ascorbic acid occurs with enzymes, eg, L-ascorbic acid oxidase, a copper protein-containing enzyme. 

Trichloracetic Acid. - This acid may also be olitained by diieel. siihslitulion of ai etir aud by ehloiine (Dumas) (see Piep. 17, ]i. 87). The o idaliou of the corresponding aldehyde is, howeiei, llu iiioie (onvenient method. Trichloracetic acid del.oiiiposes with alkalis on heating into carbon dio. ddc and chloroform,... 

Tartaric acid, 114 Terephthalic acid, i7r Tetrabromocresol, 165 7 hiocarbamide, 128 Thiocarbanilamide, 159 Thiocarbanilide, 159 Thiourea, 128 /i-Tolyl bromide, 167 / Tolyl chloride, 165 /-Tolyl cyanide, 169 Tolyliodochloride, 169 Toluene from toluidine, 163 / Toluic acid, 170 Tribromophenol, 180 Trichloracetic acid, 99 Trimethylxanthine, 131 l rinitrophenol, 185 Triphenylguanidine, ito Triphenylmetbane, 2 4 J schugac s hydroxyl method, 223 Tube furnace, 23 Tyrosine, 133... 

In the Webb and Levy test (60) for 2-deoxy pentoses, the same hydroxyaldehyde intermediate (4) (30), formed by treating the sugars with trichloracetic acid, reacts with p-nitrophenylhydrazine to yield the pyridazinium salt (5) from which a quinonoid dye (6) absorbing at 560 m/i, is formed in alkaline medium. 

NaC103 4, dextrin 3, and trichloracetic acid 1.8 parts. More than 370 formulations are described, many using germanium dioxide, boron... 

You require 0.150 L of a buffer with pH = 3.00. On the shelf is a bottle of trichloracetic acid/sodium trichloracetate buffer with pH = 2.95. The label also says trichloracetate = 0.200 M. What mass of which substance (trichloracetic acid or sodium trichloracetate) should you add to 0.1 50 L of the buffer to obtain the desired pH ... 

Glycolic acid Jessner s solution Pyruvic acid Resorcinol Salicylic acid Trichloracetic acid Deep chemical peels... 

Combinations peels salicylic acid + trichloracetic acid... 

Salicylic acid 20-30% Jessner s solution Glycolic acid 20,35,50,70% Trichloracetic acid 10-30%... 

Medium depth chemical peels 35% trichloracetic acid,50-70% pyruvic acid [7]... 

Acidification with trichloracetic acid catalyses oxidation , the fractional increase in the rate coefficient per mole of acid added, viz. Ak/ko)/[sicid], being of the order of two. Strong catalysis by alkali metal acetates has been observed for several oxidations, e.g. of m-cyclohexane-l,2-diol °, formic acid , methyl mannoside and galactoside and several a-hydroxycarboxylic acids °. 

Changing the reaction medium from acetic acid to water does not reduce the efficiency of the oxidant and, indeed, gradual dilution of an acetic acid medium with water, methanol or benzene increases the rates of oxidation of several glycols of factors of 500 to 1000 (ref. 260). This effect raises the question of whether the catalysis by trichloracetic acid vide supra) is solely an effect of acidity. 

Rates of polymerization of isobutylene in n-hexane by TiCfi with either water or trichloracetic acid as co-catalyst at —90 to 0°C have been estimated by Plesch from the adiabatic temperature rise. His... 

---