34:0 ALPHATOLUIC ACID, ETC. 



b. Alphatoluic Add (Phenylacetic Acid). 

 C 6 H 5 .CH 2 .CO.OH. 



Is produced by boiling benzyl cyanide (p. 276) with 

 alkalies ; by the action of hydriodic acid on mandelic 

 acid ; together with methyl alcohol and oxalic acid by 

 boiling vulpic acid with barium hydroxide ; by melt- 

 ing atropic acid with caustic potassa ; its ethyl ether 

 by heating a mixture of monobrombenzene and ethyl 

 chloracetate with copper to 180-200. Crystallizes in 

 broad, lustrous laminae. Very similar to benzoic acid. 

 Fuses at 76.5, and boils without decomposition at 

 261-262. Oxidized with chromic acid, it is converted 

 into benzoic acid. 



When bromine and nitric acid are allowed to act 

 upon alphatoluic acid without the aid of heat, substi- 

 tution-products result which consist principally of 

 members of the para-series, and by oxidation yield para- 

 brom- or paranitrobenzoic acids. Together with these, 

 in small quantities, are formed isomeric compounds, pro- 

 bably belonging to the meta-series. 



When mandelic acid is heated with concentrated hy- 

 drochloric acid to 140-150, and when bromine acts 

 upon heated alphatoluic acid, another class of substitu- 

 tion-products is formed, in which the hydrogen of the 

 acetic acid residue is replaced (for example : phenyl- 

 chloracetic acid C 6 H 5 .CHC1.CO.OH). 



3. Acids, C 9 H 10 2 . 



1. Mesitylenic acid, ^ 8 OH (1: 8: 5) * Is 



formed by oxidizing mesitylene with dilute nitric acid. 

 The crude acid is purified like para-toluic acid. Crystal- 

 lizes from water in small, colorless needles, from alco- 

 hol in large, transparent, monoclinate crystals. Almost 

 insoluble in cold water, very difficultly in hot water, 

 very easily in alcohol. Fuses at 166, and sublimes with- 

 out undergoing decomposition. By further oxidation, 

 it is converted into uvitic and trimesic acids. Distilled 

 with an excess of lime, it yields meta-xylene. 



