336 HIPPURIC ACID. 



chlorine at a slightly elevated temperature, it is con- 

 verted into chloracetyl benzene C 6 IF.CO.CH 2 C1 (crystal- 

 line; fusing point, 41 ; boiling point, 246). Yields 

 nitrosubstitution-products with nitric acid. Hydrogen, 

 in statu nascendi, converts it into secondary phenyl- 

 ethyl alcohol (p. 316). Oxidizing agents convert it 

 into benzoic and carbonic acids. 



Ethylphenylketone, C 6 H 5 .CO.C 2 H 5 . Is prepared 

 by the action of benzoyl chloride on zincethyl. Boil- 

 ing point, 208-212. Insoluble in water. Yields by 

 oxidation benzoic and acetic acids. 



Hippuric acid (BenzoyMycocol) C 9 H 9 N0 2 = 



( N H C 7 H 5 

 CH 2 -j pQ QTT Occurs in small quantity in normal 



human urine, in large quantity in the normal urine of 

 graminivorous animals. Toluene, benzoic acid, cinna- 

 mic acid, and oil of bitter almonds, taken into the 

 system, are converted into hippuric acid in all animals ; 

 quinic acid, in the case of man and graminivorous 

 animals, likewise undergoes the same change. Ob- 

 tained artificially, by the action of benzoyl chloride 

 on glycocol-zinc or glycocol-silver (p. 85). To prepare 

 it, fresh urine of horses or cows is evaporated to about 

 one-fourth its volume, and then acidified with hydro- 

 chloric acid, the hippuric acid being thus thrown 

 down as a crystalline magma. The yield varies very 

 much, according to the fodder of the animals, and ac- 

 cording as they have lived in stalls or in the open air. 

 The crude acid is washed out with cold water, pressed, 

 digested with a large quantity of chlorine water, and 

 finally dissolved in it at boiling temperature. On 

 cooling it separates in colorless needles. Or the crude 

 acid is dissolved in boiling weak soda-ley, sodium 

 hypochlorite gradually added until the color is removed, 

 and then, when the solution has ceased boiling, hydro- 

 chloric acid is added until the whole has an acid 

 reaction. It is completely purified by recrystallizing 

 from water. 



