138 Formation of Gly colic Acid from Acetic Acid. 



The amides were divided by Gerbaidt and Laurent into six 

 classes, all of which are derivable from neutral or acid ammonia 

 salts of monobasic or polybasic acids by the loss of water ; and 

 acediaraine would he an amide derivable from a basic ammonia 

 salt, inasmiich as by its decomposition it yields one equivalent 

 of acetic acid and two of ammonia. Strecker considers it pro- 

 bable that many of the natural alkaloids, which contain in one 

 equivalent two equivalents of nitrogen, might be derived like 

 acediaraine, from two equivalents of ammonia and one equiva- 

 lent of a neutral or acid body. 



In an investigation on monochloracetic acid, Hofmann* ob- 

 served a peculiar decomposition of its salts, in which, by simply 

 heating the air-dried salt, a metallic chloride was formed, and 

 the previously neutral liquid assumed an acid reaction. He sug- 

 gested that this might take place by the assimilation of water, 

 and an acid be formed which would have the composition of gly- 

 f*o!ip flf*i fi 



C4H2ClM04-f2HO = C'*H''06 + MCl. 



Kekulet has examined this reaction, and has found Hofmann^s 

 supposition confirmed, and that glycolic acid is in fact formed 

 from acetic acid. This is interesting, as being the first example 

 of the formation of a biatomic acid from a monoatomic acid of 

 the acetic acid group. It is in fact, in the series of acids, exactly 

 parallel to the formation of glycol from alcohol in the series of 

 alcohols. Glycolic acid bears the same relation to acetic acid 

 that glycol does to alcohol, — 



Alcohol, TT >-0^. Acetic acid, „ ?-0^ 



Glycol, ^* 2^1 0""- Glycolic acid,^' ^^ ^^\ 0\ ' 



Monochloracetate of potash, heated for some time to.l20° C, 

 becomes yellow and assumes an acid reaction. On treatment with 

 cold water, glycolic acid and chloride of potassium are dissolved 

 out, and there is left a small quantity of a white powder which 

 is glycoUde, the formation of which might be thus expressed : — 



C* 112 Kci 0*= KCl + C W 0\ 

 From the aqueous solution which still contains chloride of potas- 

 sium, the acid is easily obtained by evaporating the solution to 

 dryness, and extracting with a mixture of alcohol and sether. 

 After evaporating the alcohol the acid remains as a yellow syrup. 

 Kekule confirmed the identity of the acid by preparing and ana- 

 lysing the silver, lime, baryta, and lead salts. 



Kekule made an experiment to ascertain if this reaction ex- 

 * Phil. Mag. vol. xiv. p. 50. f Liebig's Annalen, March 1858. 



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