A Manual of the Chemistry of the Carbon Compounds

210 THE OBEM18TRY OF
+ 3HJJO is prepared by dissolving iron filings hi sour whey. It
forms nearly colourless crystalline crusts; it is but sparingly soluble
in water, and is used in medicine.
When a mixture of lactic acid and phosphorus di-iodide FtJt is introduced
in water, a iodopropionic add is formed, an oily liquid
insoluble in water, which, when heated with strong hydriodic acid
to 160°, is converted into propionic acid. This transformation of
laotio acid into propionic acid is explained by the following equations
:—
CH8
CH3
(1) CH.OH + HI = CHI +H4O
CO.OH CO.OH
CHa
CHS
(2) CHI +HI = CHj + T2
CO.OH CO.OH
Lacbyl OMoride C8H,OC1,.—This compound is obtained by distilling
two molecules of phospnorus pentaohloride with one molecule of
calcium lactate. It is a fuming liquid, which has not been obtained
quite free from phosphorus oxychloride. It is decomposed by cold
water with the formation of hydrochloric acid and a elUoropropionic
add, a colourless liquid, boiling at 186°.
CHa
CH3
HC1 + HaO = CHC1 + HC1
IOC1 CO.OH
ETHERS OP UCTIC ACID.
Ethyl Lactate, a colourless neutral liquid boiling at 156°, is produced
by heating lactic acid with absolute alcohol It is soluble in water;
its aqueous solution soon turns acid, being decomposed into alcohol
and lactic acid. Sodium dissolves in ethyl lactate with the evolution
of hydrogen. On heating the sodium compound thus formed with
ethyl iodide, diethyl lactate is formed, a liquid possessing an agreeable
odour, and boiling, like the monolactate, at 156°. By the action
of hot potash-solution it yields potassium etliyllactate; the free
ethyllaetic acid is as yet very little known. The constitution of
these ethers is shown by the following formula?:—