Chlor acetic acid

In hydrochloric-acid solution4 chlor-acetic acids occur, in, addition to the corresponding oxidation products (Riche 5). 

It reduces ammoniacal silver nitrate solution. It is oxidizable to tri-chlor acetic acid and, by the action of zinc and hydrochloric acid, is reduced to acet-aldehyde. Chloral is a most important soporific and is used in certain cases for anesthetic purposes. In this latter use it is always the readily soluble form of chloral hydrate which is employed. Its anesthetic action was, at first, attributed to the probable formation of chloroform but this is now doubted. 

This reaction of oxidation often takes place, as has been referred to in the case of tri-chlor aldehyde, or chloral, which yields tri-chlor acetic acid on oxidation. But this is not the ordinary method of preparation of the halogen acids. The commoh method of preparing these compounds is by the direct halogenation of the acids themselves. 

CH2CI—COOH Mono-chlor acetic acid, CHCI2—COOH Di-chlor acetic acid, CCI3—COOH Tri-chlor acetic acid. 

Tri-chlor acetic acid is a solid forming deliquescent crystals which melt at 52° and boil at 195°. It is strongly caustic and is used in medicine on account of this property. It is readily decomposed by boiling its solution, yielding chloroform and carbon dioxide,... 

The ether which is obtained in small yields by heating the hydroxy acid is more easily prepared by the reaction between two molecules of chlor acetic acid and potassium hydroxide. As this reaction probably takes place in two steps, the hydroxy acetic acid being first formed from the chlor acetic acid, the formation of the ether may be represented as given. The resulting compound which, in the above case, is an ether of di-(hydroxy acetic acid) is known as di-glycolic acid hydroxy acetic acid itself being glycolic acid. It yields an anhydride by the loss of water from the two carboxyls. 

The next higher hydroxy acid is hydroxy acetic acid CH2(OH)— COOH, known also as glycolic acid. It may be prepared (a) from chlor acetic acid, (b) from the cyan-hydrine obtained from formic aldehyde, or (c) hy the oxidation of ethylene glycol, by reactions which have been already discussed. Its relation to ethylene glycol gives it the name of glycolic acid. It may be considered as a direct oxidation product of ethane. 

In a similar way mono-chlor acetic acid (p. 234) by means of potassium cyanide yields mono-cyanogen acetic acid and this on hydrolysis yields malonic acid, as follows ... 

Analogous to amino acetic acid we have aniUiio acetic acid, better known as phenyl glycine, which is formed by the action of aniline upon chlor acetic acid. 

Phenyl Glycine ortho-Carboxylic Acid.—The next step toward indigo is the formation of phenyl glycine ortho-carbo3grlic acid which is an ortho-dimino derivative of a mixed ring-carboxy and side-chain-carboxy acid. With chlor acetic acid anthranilic acid forms an amino acetic acid derivative in which anthranilic acid, acting as ammonia or an amine, is substituted in acetic acid. 

Naphthalene to Anthranilic Acid.—Such a cheap source was found in naphthalene which was converted into anthranilic acid, orthoamino benzoic acid, and this by treatment with chlor acetic acid yields phenyl glycine ortho-carboxylic acid. The complete synthesis is as follows Naphthalene is oxidized to or// o-phthalic acid which then yields phthalic anhydride. This with ammonia, as ammonium carbonate, yields phthalimide or phthalamidic acid. 

Solubility of Silver Benzoate at 25° in Aqueous Solutions of Nitric Acid (N. and S.). Chlor Acetic Acid (N. and S.). 

In hydrochloric acid solution, chlor-acetic acids occur in addition to the corresponding oxidation products (Riche"). Habermann, on electrolyzing the alcohol in alkaline solution, obtained, besides carbon dioxide, an aldehyde resin (Lildersdorf and Con-nel") from which he isolated a body closely related to cinnamic aldehyde. In aqueous solution, on the addition of potassium acetate, the alcohol was split up into ethane, potassium ethyl-carbonate, carbon dioxide, and acetic ester. Also with propyl and butyl alcohols, to which potassium acetate had been added, analogous results were obtained by Habermann. 

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