dry retort of about 1 litre capacity and covered with The retort is connected with a

a layer of ether.
spiral condenser. A mixture of 100 grms. anhydrous
chloroform and 117 grms. absolute alcohol are added
drop by drop from a tap funnel. At the commence-
ment the reaction proceeds rather violently and the
retort must be well cooled with ice. The clear liquid
becomes gradually thick from the separation of sodium
chloride and changes to a brown colour. The reaction
is completed by warming the mass on the water-bath
with inverted condenser until the whole of the sodium
is converted into sodium chloride. The contents of
the retort are poured into water whereby the ethyl
orthoformate dissolved in the ether separates out on
the surface of the water in the form of a brown liquid.
The ethereal solution is drawn off, well washed with
water, separated from the aqueous layer and de-
hydrated over calcium chloride. It is then distilled
on the water-bath, and when no further liquid passes
over the distillation is continued over the bare flame.
The distillate passing over above 110° is redistilled
and the orthoformic ether is then pure.

CHCl3 + 3C2H5OH + 3Na = CH(OC2H5)3 + 3NaCi + 3H
Chloroform Alcohol
Ethyl Orthoformate.

Properties-Colourless liquid; b. p. 145-147°; sp.

gr. 8964.

PREPARATION XLVII.

POTASSIUM ETHYL SULPHATE, C2HÁОSK =
C2H2O.SO2OK.

Literature.—Berthelot (1855), Ann. Ch. Phys. (3) 43, 385; Claesson (1879), Journ. Prakt. Ch. (2) 19, 246. 500 grms. absolute alcohol

To 500 grms. commercial absolute alcohol contained in a porcelain basin about 1 litre capacity, 375 grms. conc. sulphuric acid are slowly added and the two layers quickly mixed, whereby the temperature rises to So-90°. The mixture is heated for some time on the water-bath. The product then contains in addition to the acid ether, free sulphuric acid and unchanged alcohol. On cooling, the liquid is diluted by first adding ice to prevent any great increase of temperature, and then water. It is neutralised with chalk ground into a paste with water. The filtered solution of calcium ethyl sulphate made slightly alkaline with lime water, may be concentrated on the water-bath without fear of decomposition. By adding a concentrated solution of potassium carbonate until the calcium is just precipitated, the soluble potassium salt of ethyl sulphate is formed, which is separated by filtration from the precipitated calcium carbonate.

The clear solution, with the addition of a small quantity of potassium carbonate, can be evaporated without decomposition on the water-bath until crystallisation begins. By slowly concentrating the liquid a well crystallised product may be obtained.

C2H5OH + H2SO4 = C2H¿SOH + H2O.

=

Ethyl Sulphate.

(C2H5SO4)2Ca + H2O + aCO2 Calcium Ethyl Sulphate.

(C2H5SO4)2Ca + K2CO2 = 2C2H2SOK + CaCO3

Potassium Ethyl Sulphate.

Properties.-Colourless, foliated crystals; easily soluble in water and dilute alcohol; insoluble in absolute alcohol and ether.

PREPARATION XLVIII.

PROPIONITRIL, C2H,N=C,H,CN.
(Ethyl Cyanide.)

LITERATURE.-Pelouze (1834), Ann. Ch. Pharm. 10, 249 Linnemann (1868), Ann. Ch. Pharm. 148, 252; Rossi (1871), Ann. Ch. Pharm. 159, 79.

50 grms. potassium ethyl sulphate

Fifty grms. finely powdered potassium ethyl sul phate dried at 100,° and 50 grms. dry powdered commercial potassium cyanide are thoroughly mixed

and introduced into an iron tube closed at one end, which is one-third filled with the mixture. A small channel is formed along the upper surface to allow the gaseous products to escape by tapping the tube horizontally. The tube is placed in a combustion furnace, the open end of which should project about 3 cm. from the furnace (Fig. 17) and is connected with a condenser and receiver. The mixture is carefully subjected to dry distillation, beginning at the front end and proceeding gradually towards the closed end of the tube. The yellowish brown oily distillate, which possesses an unpleasant smell, is re-distilled, and the portion passing over below 110° and consisting of propionitril, isopropionitril, alcohol, and water, collected. Isopropionitril is dissolved out by shaking the distillate with a small quantity of conc. hydrochloric acid. The oil floating on the surface of the acid is separated, washed with a small quantity of water, dehydrated with calcium chloride and anhydrous potassium carbonate, and then distilled. The propionitril dissolved in the washings may be separated by adding calcium chloride.

C,H,SO,K + KCN = C2HCN + K2SO4
Potassium Ethyl Sulphate Propionitril.

Properties.-Colourless liquid having a peculiar ethereal smell; b. p. 98°; sp. gr. 0.789 at 12°; somewhat soluble in water.

PREPARATION XLIX.

PROPIONIC ACID, C2H¿O2=CHCH2CO.OH. LITERATURE.-Gottlieb (1844), Ann. Ch. Pharm. 52, 127; Frankland, Kolbe (1848), Chem. Soc. J. 1, 60; Ann. Ch. Pharm. 65, 269; Williamson (1853), Phil. Mag. (4) 6, 204; Rossi (1871), Ann. Ch. Pharm. 159, 79 ; Beckurts, Otto (1877), Ber. 10, 262.

To 50 grms. ethylcyanide contained in a roundbottomed flask of about 1 litre capacity, and connected with a reflux condenser, 150 grms. of a mixture of 2 vol. water and 3 vol. conc. sulphuric acid are slowly added and allowed to stand for some time. mixture is then heated to 100° without disconnecting the condenser. The originally clear liquid becomes cloudy owing to the separation of propionic acid, which is insoluble in the solution of ammonium

The

sulphate formed during the reaction. When no more oil separates out on the surface of the liquid (with 50 grms. of the cyanide about 12 hours heating is necessary) the reaction is complete. After allowing the liquid to cool down to 50°, the almost colourless acid is separated and purified by distillation.

2C2H5CN+H2SO + 4H2O = 2C2H5COOH + (NH4)2SO4 Ethyl Cyanide Propionic Acid.