OXYPROPIONIC ACIDS. 149 



Potassium and sodium are dissolved in it with evolu- 

 tion of hydrogen, and by the action of ethyl iodide on 

 the resulting compounds are formed 



Ethyl ethyllactate (lactic-diethylether), C 2 H 4 



(O O 2 TT 5 

 CO C 2 H 5 ^is * s a * so P r0( ^ uce d by the decomposi- 



tion of chlorpropionic ether with sodium ethylate. 

 Colorless liquid, insoluble in water, boiling at 126.5. 

 Treated with caustic potassa, only one atom of ethyl 

 is replaced by potassium, and there is formed a potas- 

 sium salt of 



{n P 2 TT 5 

 CaOH. This is a strong 



acid and isomeric with ethyl lactate. 



When lactic acid is heated for a long time at 140- 

 145, it is converted into dilactic add C 6 H 10 5 , a yellow, 

 amorphous substance, which, when boiled with alka- 

 lies and acids, is reconverted into lactic acid. 



Lactide (lactic anhydride), C'HO 2 = CH 3 .CH j ^ Q > 



The distillate from lactic acid is evaporated at 100; 

 the residue washed with cold absolute alcohol and 

 crystallized from hot alcohol. llhombic plates, fusing 

 at 107, but slightly soluble in water, slowly uniting 

 with it to form lactic acid. 



Trichlorlactic acid, CCP.CH j QJ^ OH When 



hydrocyanic acid is allowed to act upon chloral, the 



{OTT 

 n-ff is obtained, 



which yields the acid when digested with moderately 

 concentrated hydrochloric acid. Crystalline mass, con- 

 sisting of small prisms; fusing point, 105-110 ; yields 

 crystallizing salts. 



Lactyl chloride, C 3 H 4 C1 2 = CH 3 .CHC1.CO.C1, is 



formed by the distillation of zinc lactate with double its 



13* 



